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TABLE OF CONTENTS

HOW TO ACHIEVE YOUR GOALS ........................................................................................................... 6

WELDING DISTORTION ENGINEERING .................................................................................................................................. 6

WELD QUALITY ENGINEERING ............................................................................................................................................. 8

AVAILABLE WELDING SIMULATION PACKAGES .................................................................................. 11

WELD PLANNER PROFESSIONAL PACKAGE ........................................................................................................................ 12

WELDING ASSEMBLY PACKAGE ......................................................................................................................................... 12

WELDING PACKAGE ............................................................................................................................................................ 12

THE WELDING SIMULATION SOLUTION ............................................................................................................................. 12

WELDING - UNIVERSITY EDUCATION ................................................................................................................................. 12

PREPARATION OF THE CAD MODEL ................................................................................................... 13

DISTORTION ENGINEERING - QUICK EVALUATION ............................................................................. 14

IMPORT FROM VISUAL MESH .............................................................................................................................................. 14

LOOKING INTO JOINT DETAILS ........................................................................................................................................... 15

GENERATE NEW JOINTS ...................................................................................................................................................... 15

DISPLAY / INVERSE THE RUNNING DIRECTION OF JOINTS ................................................................................................. 16

SPLIT JOINTS IN DISCONTINUOUS SECTIONS ...................................................................................................................... 16

MODEL THE PROGRESSION OF WELDING FABRICATION .................................................................................................... 17

DETERMINE THE LENGTH OF WELDING JOINTS ................................................................................................................. 17

CHECK THE JOINT SIZE THAT WILL SHRINK ....................................................................................................................... 17

DEFINE / CHECK PROPERTIES OF CLAMPS .......................................................................................................................... 18

DEFINE / CHECK PROPERTIES OF OBJECTS ......................................................................................................................... 18

DEFINE THE WELD PLAN..................................................................................................................................................... 19

SOLUTION ............................................................................................................................................................................ 20

Generate the Input for the Solution .............................................................................................................................. 20

Generate the Input for a Transient Solution in VISUAL WELD ..................................................................................... 20

Solve the Project ............................................................................................................................................................ 20

POST-PROCESSING ............................................................................................................................................................... 21

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Load the Result File ....................................................................................................................................................... 21

Display Results............................................................................................................................................................... 22

Tolerance Evaluation .................................................................................................................................................... 23

Stresses and Plastic Strains .......................................................................................................................................... 23

COMPENSATION - EXPORT OF THE DEFORMED GEOMETRY .............................................................................................. 24

Modification of the Mesh Coordinates with Computed Results.................................................................................. 24

DISTORTION ENGINEERING - PROCESS SECURITY .............................................................................. 25

SECURE THE WELDING FABRICATION ................................................................................................................................ 25

SET UP AND RUN THE SIMULATION IN 9 EASY STEPS ........................................................................................................ 25

Step 1 Project Description ....................................................................................................................................... 25

Step 2 Definition of the Global Parameters ............................................................................................................ 26

Step 3 Definition of Component Properties ............................................................................................................ 27

Step 4 Definition of the Welding Process ................................................................................................................ 27

Step 5 Definition of Cooling Conditions ................................................................................................................. 28

Step 6 Definition of Clamping Conditions .............................................................................................................. 28

Step 7 Definition of Loads and Deformations ........................................................................................................ 29

Step 8 and 9 Definition of Solver Parameters and Solution Launch ..................................................................... 29

POSTPROCESSING................................................................................................................................................................. 30

PRECISION DISTORTION ENGINEERING FOR HUGE MODELS .............................................................. 33

GLOBAL MODEL SIMULATION PAM-ASSEMBLY ...................................................................................................... 34

WELD PARAMETERS AND VIRTUAL MATERIAL DATA GENERATION / MANAGEMENT ....................... 41

WELDWARE ..................................................................................................................................................................... 41

WELDING PARAMETERS ........................................................................................................................................... 42

DETAILS OF THE WELDING PARAMETERS ........................................................................................................... 43

VALIDATION OF THE COOLING TIME ................................................................................................................... 44

PRE-HEATING .............................................................................................................................................................. 45

WELD GEOMETRY PARAMETERS ............................................................................................................................ 46

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POST-WELD PARAMETERS ....................................................................................................................................... 47

MATERIAL DATA GENERATION AND MANAGEMENT ....................................................................................... 48

WELDING CCT DIAGRAMS........................................................................................................................................ 48

MECHANCIAL PROPERTIES DEPENDING ON COOLING RATES ..................................................................... 50

Calibration of Yield Stress and Strain Hardening ....................................................................................................... 51

Calibration of PHase Transformations ........................................................................................................................ 52

Material Data Manager ................................................................................................................................................ 53

WELD QUALITY FABRICATION DETAILS ........................................................................................... 54

SINGLE-PASS AND MULTI-PASS WELDING WITH A COUPLE OF PASSES ........................................................................... 54

WORKFLOW ......................................................................................................................................................................... 56

SELECTED EXAMPLES AND COMPUTED RESULTS .............................................................................................................. 56

MULTI-PASS WELDING FOR THICK MATERIAL WITH MANY PASSES ............................................................................... 64

SPOT WELDING .................................................................................................................................. 66

DISTINCTIVE COMPETENCE ................................................................................................................ 68

GENERAL FEATURES ........................................................................................................................................................... 68

WELDING DEDICATED GENERAL CAPABILITIES ................................................................................................................ 68

WELDING DEDICATED MESHING ........................................................................................................................................ 68

GENERAL SOLVER CAPABILITIES ....................................................................................................................................... 69

WELDING DEDICATED SOLVER CAPABILITIES ................................................................................................................... 69

WELDING DEDICATED POST PROCESSING FOR TRANSIENT WELDING ............................................................................. 71

FAST SHRINKAGE METHODS ............................................................................................................................................... 71

LOCAL GLOBAL DEDICATED GRAPHIC USER INTERFACE AND SOLVER CAPABILITIES ................................................... 71

WELDING DEDICATED GRAPHIC USER INTERFACES ......................................................................................................... 72

CHAINING WITH SHEET METAL FORMING .......................................................................................................................... 72

CHAINING WITH HEAT TREATMENT FOR POWER TRAIN APPLICATIONS .......................................................................... 73

GETTING VALUE ................................................................................................................................. 73

GENERAL OBJECTIVES ........................................................................................................................................................ 73

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INDUSTRIAL BENEFITS ........................................................................................................................................................ 74

IMPROVEMENT OF THE PERFORMANCE AND QUALITY OF THE PRODUCT ......................................................................... 75

DISTORTION ENGINEERING COST REDUCTION.............................................................................................................. 76

POSITION IN THE PRODUCT CY CLE ..................................................................................................................................... 76

GETTING DETAILED INFORMATION FOR R&D .................................................................................... 78

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HOW TO ACHIEVE YOUR GOALS

WELDING DISTORTION ENGINEERING

Your goal is to get a stress minimized welding assembly within tolerances at minimum cost, keeping the specs and

securing the production.

Distortion needs to be kept within tolerances.

Tell me the stress level in the structure and I tell you how good the design is is often heard. Residual stresses can

cause a change of shape in cases of painting or assembly changes when the assembled body is modified to fit design

variants. Residual stresses have a negative impact on fatigue.

You want to

Keep distortion within given tolerances

Develop a weld plan

Identify distortion directions and magnitude

Minimize gap fit up forces

Minimize deviation from fixture forces

Minimize the amount of weld consumables needed

Minimize clamp tooling

Reduce the amount of prototyping and distortion repair work

You want to manage all those aspects at their best, at minimum cost, in the minimum time.

Using the Welding Simulation Solution from ESI you will achieve this goal. You can reduce 3-6 months needed for the

design and fabrication planning of complex assemblies by 20% to 50%.

How does it work? First, a quick evaluation of the welded assembly is done using the WELD PLANNER. With simulations

in weld blocks, it takes only minutes to indentify the welds that cause the majority of the distortion. Once identified,

clamping conditions and weld sequences can be optimized for the identified joints. This takes again only minutes for

each variant. The optimization of the clamping tools without simulation is a difficult task the more clamped, the

more stresses will be conserved in the structure, which is completely the contrary of the goal. The less clamped, the

more distortion develops, but the tolerances need to be kept. The WELD PLANNER will help you to quickly find the best

compromise, in less than a day. At the end of the evaluation, a complete sequence can be performed to confirm the

global picture.

Once the evaluation is carried out which should not take more than half a day to one day based on an existing

mesh the fine tuning of the assembly can be performed with PAM-ASSEMBLY. Focusing on the critical joints, variants

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in energy / unit length of weld, welding process, material variants, etc. can be investigated. At this step, you will add

precision to your decision.

In order to validate and secure the production, you can simulate microstructure, distortion, residual stresses and

plastic strains on the full structure, including all the physics of material and all process details.

The WELD PLANNER writes directly an input deck for VISUAL WELD. The rest is done by the computer. It is done pretty

fast, even for huge welded assemblies the SYSWELD solver is today available in DMP and solves huge problems in

less than a day.

For advanced users today, it is possible to chain the Welding Assembly simulation with sheet metal forming

simulations carried out in PAMSTAMP 2G.

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WELD QUALITY ENGINEERING

Your goal is to get the best possible welded design. You want to secure virtually - your welding manufacturing

processes, including all fabrication details. You want to avoid failure of critical welded designs knowing that even

the failure of a simple weld causes the failure of the design.

You want to

Investigate in detail the distortion, microstructure and residual stress consequences of variants in the

welding fabrication process.

Check the feasibility of welded designs but with high precision.

Avoid backside temperature problems (overheating of critical areas in a weld repair process).

Avoid failure due to a wrong microstructure.

Control and minimize distortion with the highest possible precision.

Control distortion that can cause failure by buckling if the welded member is subjected to compressive

stresses.

Avoid stress corrosion cracking (SCC, unexpected sudden failure of normally ductile metals subjected to a

tensile stress in a corrosive environment).

Avoid failure by producing uniform stress distribution and avoiding stress concentrations.

Uncover residual stress spots all over the design due to the welding fabrication process, and avoid

fatigue problems.

Avoid crack initiation due to tensile stresses at the wrong place

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Minimize the overall residual stress level to avoid problems when painting at high temperatures or

modifying the initial design.

Despite the complex physics of material involved, the tool should be easy and straight forward to use.

You expect nothing but the best possible result quality.

VISUAL-WELD gives you the answers. VISUAL-WELD has been designed with the objective to give you an easy access to

more than 100 man-years of experience in welding simulation. Running the SYSWELD solver, VISUAL-WELD offers the

best possible combination of user-friendliness and result quality. The new DMP version allows you to treat even

huge welding cases in a short time frame.

VISUAL WELD

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Speed up with the DMP version as a function of the processors with the DMP version

0

2

4

6

8

10

0 4 8 12 16 20 24 28 32 36

Nbr Processors

Sp

ee

d U

p

CPU SYSWELD

ELAPSE SYSWELD

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AVAILABLE WELDING SIMULATION PACKAGES

The product offer from ESI GROUP in the field of welding simulation distinguishes between distortion engineering

and weld quality. In order to provide the maximum efficiency, three simulation methods exist. For each method (and

thus for each engineering domain), a dedicated package is available.

Methods, engineering domains and available packages

Distortion Engineering Early design and fabrication planning phase - Shrinkage method Weld Planner

Package

Distortion Engineering Get precision in your decision - Local-global method Welding Assembly

Package

Weld Quality and Residual Stress Engineering - Process security and fabrication details - Transient method

Welding Package

The Welding Simulation Solution includes amongst others single pass welding, multi-pass welding, and spot welding.

The heat effects of arbitrary welding processes can be predicted, allowing distortion engineering, and weld quality

and residual stress control. The Welding Simulation Solution is being successfully applied in the Commercial Vehicle

and Automotive Industry, Heavy Industry, the Energy Industry, Nuclear Industry, and the Shipbuilding Industry. A

significant simulation engineering knowledge base is provided with the software and extensive in-depth training

courses are available on all aspects of welding simulation engineering. The following program packages are available

starting from March 2010.

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WELD PLANNER PROFESSIONAL PACKAGE

This package is dedicated to supporting distortion engineering for large-scale welded assemblies, making use of a

shrinkage method.

Engineers use it to identify, in the shortest possible time range, distortion critical weld joints, clamping conditions

and weld sequences to minimize distortion, and the distortion magnitude.

It includes VISUAL MESH, VISUAL VIEWER, and the WELD PLANNER, which has been developed under the guidance of

INPRO, Daimler, VW and Thyssen. It offers a fast shrinkage method and allows distortion engineering within one day.

WELDING ASSEMBLY PACKAGE

This package is dedicated to supporting distortion engineering for large-scale welded assemblies, making use of the

local-global method.

Engineers use it to compute distortion with precision, including all physics.

It includes VISUAL MESH, VISUAL WELD and PAM-ASSEMBLY. It offers a fast local-global method that allows distortion

engineering for large scale structures including all physics.

WELDING PACKAGE

This package is dedicated to supporting weld quality and structural stress engineering.

It includes VISUAL MESH, VISUAL WELD and VISUAL VIEWER. It offers a transient method with a temperature field that

moves in time on the global structure. It helps you to simulate distortion, weld quality and residual stresses for

single-pass welding, multi-pass welding, spot welding and other welding processes. It is dedicated in particular to

give answers on questions related to temperature field, changes in microstructure, hardening, stresses and material

exposure.

THE WELDING SIMULATION SOLUTION

The Welding Simulation Solution includes all packages.

WELDING - UNIVERSITY EDUCATION

This package is concordant with the Welding Package, but node limited.

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PREPARATION OF THE CAD MODEL

The Welding Simulation Solution is based on the method of Finite Elements. The mesh is generated based

on a CAD model, using VISUAL MESH. All commonly used CAD interfaces are available.

With the Welding Simulation Solution of ESI, you can treat shell, shell-solid and solid structures.

Meshing of the CAD model in VISUAL MESH

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DISTORTION ENGINEERING - QUICK EVALUATION

The WELD PLANNER is used in this first engineering step.

IMPORT FROM VISUAL MESH

In the object tree on the right side, you will find components, welds and clamps. As defined in VISUAL MESH.

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LOOKING INTO JOINT DETAILS

Mark joints in the object tree and look into joint details.

GENERATE NEW JOINTS

Via Weld Seams Weld Detection Find all Welds, new welds are detected wherever components

have nodes in common. You have several options to guide this process.

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You can generate welds in the Menu Weld Seams either under Weld Detection or Weld Definition.

Many options allow you to generate weld joints as you wish.

DISPLAY / INVERSE THE RUNNING DIRECTION OF JOINTS

Click with the right mouse button on a weld joint. You can see animated arrows that show the running

direction. Click on , then display the running direction again. The running direction has been

reversed.

SPLIT JOINTS IN DISCONTINUOUS SECTIONS

In order to be able to simulate a weld joint that is fabricated in discontinuous sections, you can split welds.

The split weld will be automatically deleted, and only the subsets will be kept. You can re-join the subsets

into welds again if required.

Below, the joint has been split in two parts.

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MODEL THE PROGRESSION OF WELDING FABRICATION

In order to simulate the progression of the fabrication of a weld, you do not need to split it. You can rather

define in Process Definition how many fabrication steps you want to simulate along a weld joint.

DETERMINE THE LENGTH OF WELDING JOINTS

The length of welds can be displayed at any time.

CHECK THE JOINT SIZE THAT WILL SHRINK

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Click on Visual Effects Generate Tubes or Generate Spheres. All what is inside the tubes or spheres

will shrink in the simulation.

DEFINE / CHECK PROPERTIES OF CLAMPS

Click on a clamp in the object tree. In the right bottom corner of software window, the properties related

to the marked object are listed and can be defined / modified / checked.

DEFINE / CHECK PROPERTIES OF OBJECTS

Click on any object in the object tree. In the right bottom corner of software window, the properties

related to the marked object are listed and can be defined / modified / checked.

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DEFINE THE WELD PLAN

Display all objects that should be included in the weld plan.

Then click on Process Definition .

Definition of the Welding Sequence

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SOLUTION

GENERATE THE INPUT FOR THE SOLUTION

Click on Input Deck and generate the input files

for the solution. Make sure to choose the computation option (non-linear or linear) prior to generating the

input files. Now you can directly solve using the shrinkage method

GENERATE THE INPUT FOR A TRANSIENT SOLUTION IN VISUAL WELD

A file is written, that contains all groups for a transient analysis as needed by VISUAL WELD. You can load the

file in VISUAL MESH and inspect all generated groups.

SOLVE THE PROJECT

Click on Calculation and solve the project. The

progress is shown in a progress window.

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POST-PROCESSING

LOAD THE RESULT FILE

Click on Result Analysis and load the result file.

Distortion of a car chassis with 2.7m length of weld joints. The sequential simulation takes about 10

minutes.

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Distortion of a bridge segment spanning over several meters. The one step simulation takes around one

minute.

DISPLAY RESULTS

Values of computed displacements can be displayed in an information window. Generate the window

(mark Show / Hide with a hook) and then define the size of the information window with the scroll bar.

Next, select the value you want to display under Label. Zoom into the part and move the nodes you want

to measure inside the information window. You need to click once in the information window before the

display of values is activated.

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Distortion Values

TOLERANCE EVALUATION

With a tool based on Microsoft Excel, you can evaluate tolerances.

Computed distortion (blue) against tolerances (red)

STRESSES AND PLASTIC STRAINS

Stresses and plastic strains are as well computed and can be reviewed with VISUAL VIEWER. The shrinkage

method gives you an idea of the stress level in the structure. You could do a quick evaluation of the fatigue

life at this stage.

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V. Mises stresses as computed with the WELD PLANNER

COMPENSATION - EXPORT OF THE DEFORMED GEOMETRY

MODIFICATION OF THE MESH COORDINATES WITH COMPUTED RESULTS

Load the assembly, load the result and click on Tools Apply Displacements. The mesh coordinates will

be modified with a scaling factor of 1. Then you can export the deformed mesh.

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DISTORTION ENGINEERING - PROCESS SECURITY

SECURE THE WELDING FABRICATION

When you export the mesh with joints and clamps in SYSWELD format, all necessary groups to set up a

transient welding simulation are generated, and you can directly start to define the transient welding

fabrication simulation using VISUAL WELD.

Welding Fabrication Simulation in VISUAL WELD

It will take only 30 minutes to define all the details of the transient welding process, for example energy /

unit length of weld and others. Then you can directly start a transient analysis, including all the physics of

welding, like temperature field, phase transformation, transformation plasticity and so on.

SET UP AND RUN THE SIMULATION IN 9 EASY STEPS

In the following, you get a quick overview on 9 simple steps to set up and run a simulation.

STEP 1 PROJECT DESCRIPTION

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In this first step, the title of the project and the working directory are set. There is the possibility to enter a

description of the project, and the used material.

Project description

STEP 2 DEFINITION OF THE GLOBAL PARAMETERS

Now the global model parameters are set. From the mesh loaded, it usually determines these parameters

automatically. The mesh is prepared with VISUAL MESH.

Global parameters in VISUAL MESH

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STEP 3 DEFINITION OF COMPONENT PROPERTIES

The components are identified in the object tree and in a list of components. Now the material assignment

happens. In case of shell-meshed component, the thickness of the components needs to be entered

additionally.

STEP 4 DEFINITION OF THE WELDING PROCESS

The welding process is defined in this step. Based on an energy / unit length of weld approach, the

definition is simple and safe. In case you want to define or use your own heat source, you can do this at

this stage.

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STEP 5 DEFINITION OF COOLING CONDITIONS

Now the cooling conditions are defined. You can define several different cooling conditions to manage all

kind of natural and forced cooling conditions.

STEP 6 DEFINITION OF CLAMPING CONDITIONS

The clamping conditions are another important factor. You can define rigid and elastic clamping conditions

to match all fabrication situations.

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STEP 7 DEFINITION OF LOADS AND DEFORMATIONS

External loads and deformations are defined to model compensation due to fixture or external loads to

apply for fatigue conditions.

STEP 8 AND 9 DEFINITION OF SOLVER PARAMETERS AND SOLUTION LAUNCH

Only the minimum information is needed at this stage.

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POSTPROCESSING

Temperature field of the transient welding process as computed with VISUAL WELD, taking into account all

the physics of material and welding process details.

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Activation of control boxes via double - click

Animation of the results

Animation of the results

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Comparison of model variants, synchronizaiton of the display, display of the model differences in a new

window and step by step animation

Comparison of the distortion of two variants, display of the difference in a new window

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PRECISION DISTORTION ENGINEERING FOR HUGE MODELS

Welding assembly design and fabrication simulation for large-scale assemblies, using a temperature field

on the global structure, is not fast enough to keep the pace of engineers and designers in the early product

phase. The time-consuming part of such a welding fabrication simulation is the mechanical simulation.

However, what is a large-scale assembly? On a reasonable single processor PC, using a mesh with around

50,000 nodes, around 200 mechanical time steps can be performed in a few hours. One mechanical time

step covers the maximum time needed to cross half of the typical length of the molten zone (the heat

source is moving stepwise) or 1/10th of the time needed to deposit a bead instantaneously. If the total

length of the simulated joints exceeds approximately 100 times the typical length of the molten zone or 20

instantaneous welds, a welding simulation with a temperature field on the global structure starts to be

time consuming.

To overcome this limitation, and to avoid the necessity that designers need to deal with nonlinear Finite

Element simulations on the full structure, the local-global approach has been developed.

First, inner residual forces due to the heat effects of welding are computed remote from the global

structure, on a local model. Then, the residual inner forces are extracted and transferred to the global

model, and the distortion of the global structure is computed.

To be consistent with t8/5 (steel) or t4/1.5 (aluminum) guidelines, various technologies are included to

ensure that the computed internal forces in the local models are representative of the internal forces

actually generated in the global structure.

One advantage of this method against others is the fact that no physics is suppressed and the residual

forces are computed using a sufficient mesh density, which is not possible for large-scale structures.

Another advantage is the fact that all distortion modes are well treated there is no simplification in the

local model. Consequently, precise results can be achieved.

Distortion Engineering is also included in weld quality and stress engineering. The computation time is

however longer, and the maximum feasible part size is determined by the available time and computer

configuration.

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GLOBAL MODEL SIMULATION PAM-ASSEMBLY

Representative Objects that have been treated with Pam-Assembly

After more than five years validation by many industrial partners, PAM-ASSEMBLY is addressed to designers,

planners and manufacturing practitioners to help them quickly simulate distortion due to the heat effects

of welding. PAM-ASSEMBLY computes the displacements after each step of an assembly sequence and after

unclamping. The user is able to optimize, compare and finally select the best possible welding sequence

and choice of clamping tools. PAM-ASSEMBLY does not require any advanced knowledge in simulating the

highly nonlinear physics of welding as it is based on an intuitive process building solution.

In PAM-ASSEMBLY, the local-global method is applied to simulate the effects of welding assembly. It is the

most efficient method for large-scale assembly designs. PAM-ASSEMBLY serves as an easy-to-use front end to

perform welding assembly simulations. The physics of welding is fully treated in the local models, which are

simulated with the VISUAL LOCAL MODEL ADVISOR. The basic idea behind the local-global method

implemented in PAM-ASSEMBLY is to provide precision in Advanced Manufacturing simulation without

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simplification of the physics of welding, whilst remaining user-friendly and efficient with respect to

computation time, even for large-scale assemblies.

PAM-ASSEMBLY includes the following benefits that reduce time needed for simulation engineering to a

minimum.

Local model results are stored in a library, which can be filled offline from the global

simulation. Once generated, the library is available for other simulations as well

Automatic detection of components, welding paths and components to be welded

Graphically guided positioning of cross sections of local models

Fully automatic embedding and mesh linking between local models and the global structure.

This will save more than 90% of the time needed against conventional meshing methods. It

takes into account CAD imperfections

Fully automatic extraction of inner forces from the local model and generation of loads for the

global model

The meshing workflow is illustrated hereafter. It saves 90% of the time against usual methodologies

Positioning of a welding cross section along a weld path

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Insertion of solid elements along the trajectory, taking into account all CAD imperfections

Automatic re-meshing to guarantee a compatible mesh

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Further usage also as shell-only application

Auto-Meshing Application Example

Automatic insertion of welding joints in shell meshed components - Courtesy Automobilarbeitskreis

(German Automotive Industry)

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Positioning of cross sections

Extrusion of cross-sections, taking into account CAD imperfections in the components

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Re-meshing of components for FEM compatibility The mesh is also usable for a shell-solid analysis

Mesh usable for Welding Macro Element or shell analysis

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Details

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WELD PARAMETERS AND VIRTUAL MATERIAL DATA GENERATION / MANAGEMENT

WELDWARE

WeldWare is a modular welding advisory system which serves for the calculation of heat procedures in welding. The output is taken as input for distortion, weld quality and residual stress analysis on complex

structures.

WeldWare is a product from SLV M-V GmbH Rostock / Germany. It works well together with the ESI

Welding Suite.

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WELDING PARAMETERS

WeldWare allows the determination of heat input and pre-heat temperature for the best weld quality.

The heat input module works not only for unalloyed steels but for high alloyed steels as well as aluminium,

titanium or nickel alloys, too.

The cooling time given above depends on the material behaviour during welding (module CCT diagram,

microstructure, and Heat Affected Zone properties). If WeldWare determinates a too high heat input due

to the chosen process to achieve the cooling time the user gets this information, otherwise the calculated

value.

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DETAILS OF THE WELDING PARAMETERS

Based on the computed heat input current, voltage and speed can be determined.

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VALIDATION OF THE COOLING TIME

The cooling time for best weld quality can be determined using idealized geometries.

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PRE-HEATING

In case needed a preheating temperature also can be determined via additional formulas.

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WELD GEOMETRY PARAMETERS

Weld geometry parameters like weld cross section and number of layers can be determined.

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POST-WELD PARAMETERS

In case post-weld heat treatment is needed the best possible parameters can be computed.

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MATERIAL DATA GENERATION AND MANAGEMENT

WELDING CCT DIAGRAMS

Based on the chemical composition a welding CCT diagram can be computed.

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MICROSTRUCTURE DEPENDING ON COOLING RATES

Based on the chemical composition the microstructure can be computed for typical cooling rates.

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MECHANCIAL PROPERTIES DEPENDING ON COOLING RATES

Based on the chemical composition mechanical properties can be computed for typical cooling rates. The

mixture of base and wire material can be computed for carbon or low alloyed steels. Based on the new

chemical composition further analysis can be performed.

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CALIBRATION OF YIELD STRESS AND STRAIN HARDENING

Based on WeldWare or measured data, the yield stress and the strain hardening of phases can be

calibrated depending on the temperature. The data of austenite is hard wired.

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CALIBRATION OF PHASE TRANSFORMATIONS

Based on WeldWare or measured data, the phase transformations can be calibrated for usage in

SYSWELD.

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MATERIAL DATA MANAGER

The material data manager allows gathering all calibrated material data. Thermo-physical properties of all

steel classes are hard-wired. A material database in SYSWELD format can be exported and imported.

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WELD QUALITY FABRICATION DETAILS

In a transient welding simulation, the heat source is applied to the global structure. This method is applied

in case engineers need to investigate the details of the welding fabrication. The temperature field, changes

in microstructure, hardening, distortion, stresses, and the yield stress depending on the microstructure and

material exposure is computed for the complete structure and available for any stored time step.

SINGLE-PASS AND MULTI-PASS WELDING WITH A COUPLE OF PASSES

To validate the process security of welded designs with contiguous welds of thin- and thick-walled

structures, VISUAL WELD is available. The simulation solution of the welding fabrication task is performed by

SYSWELD in black box mode.

VISUAL WELD Multi-Pass Welding

VISUAL WELD helps to plan and set up transient welding simulations of the heat effects of welding, based on

the method of Finite Elements. It performs a task planning and set up for the SYSWELD multi physics solver

and is applicable in all kind of Industries: Commercial Vehicle and Automotive Industry, Ship Building,

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Aerospace and Energy / Nuclear. The major benefits are virtual control of distortion, stresses, hardening,

and microstructure and material exposure.

VISUAL WELD in combination with the SYSWELD solver allows addressing MIG, MAG, TIG, Submerged Arc, and

Electrode, Laser, and Electron Beam Welding processes. All types of metallic material can be treated, as

aluminum alloys series 2000 to 7000, standard and high-strength car body steel, structural steels, high-

strength quenched and tempered structural steels, high-alloy ferritic and pearlitic-martensitic steels, high-

alloy austenitic steels, quenched and tempered steels, case hardening steels, titanium alloys and others.

The welding sequence, the weld time or weld velocity and the energy per unit length of weld can be

manipulated. Complex heat sources can be used on demand. Rigid and elastic clamping conditions help to

model the fabrication conditions based on the real stiffness of the clamping tools.

There is no limitation in the simulation of the physics of the heat effects of welding. The user does not deal

with numerical details the solution process is fully automatic and the necessary material behavior to be

simulated is recognized.

The following fabrication conditions can be included in a simulation:

Pre-heating

Welding with Multiple Sources

Hybrid-Welding

Contiguous joints fabricated in sections

Post heat treatment of joints

Tack welds

Simulation of contact between components

Elastic distortion compensation when clamping

Unclamping and re-clamping

One-directional stops

External loads (gap closing, compensation distortion)

Self weight

It is important to understand that the generic capabilities of SYSWELD offer all capabilities for welding

simulation, also for very advanced analysis, for example chaining with heat treatment simulation, turning,

press fitting, etc. Some of those operations will require an advanced usage of the generic SYSWELD program

and are not available through the shop floor dedicated process definition interface.

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WORKFLOW

Please refer to chapter Distortion Engineering - Process Security. A typical object is displayed below.

SELECTED EXAMPLES AND COMPUTED RESULTS

There is no particular limitation in the possibilities to simulate welding fabrication of welded designs.

Typical examples are components of frames and suspension systems in transportation industry, exhaust

systems, power train components or weld specimen for arbitrary purpose.

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Courtesy SKODA Power Steam Turbine Assembly

Comparison of computed results and measurements

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Specimen - ITER

Comparison of computed results and measurements

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Courtesy Automobilarbeitskreis Chassis component

BMW 1-series, cross tube of front axle carrier, Courtesy BMW

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BMW 1-series, cross tube of front axle carrier, Courtesy BMW Temperature field validation

Generation of geometry and mesh in VISUAL MESH

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Geometry and mesh are done in VISUAL MESH

VISUAL MESH is a state of the art product for meshing CAD geometry

VISUAL MESH includes particular features to support welding simulation

Post-processing in Visual Viewer - Temperature field

Retained martensite

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Distortion after unclamping

Residual stresses in welding direction the effect of phase transformations

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Accumulated plastic strains generated in the austenite phase

Yield stress at the end

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MULTI-PASS WELDING FOR THICK MATERIAL WITH MANY PASSES

Multi-pass welding joints are a very important part of thick walled designs with many passes (50 to 500, to

give an idea). Defects occur very often in such joints. Tensile stresses at the surface have negative influence

on the structure lifetime and the brittle fracture resistance. This is in particular a problem for stress

corrosion cracking at the roots of the welds. Residual stresses create a balanced system of inner forces,

which exists even under no external loading. The welding joints have to be designed and produced with

care.

ESI group has developed a MULTI-PASS WELDING WIZARD for designs with hundreds of passes that helps the

user to manage multi-pass welding. It simplifies significantly the workload of the user. All welds involved in

the multi-pass process are computed according to the scheme initially defined in the Standard Welding

Wizard. When the project is stored the mesh is checked, updated and all input data for the multi-pass

welding simulation is automatically created.

Tools for multi-pass welding

There is no particular limitation in the possibilities to simulate multi-pass welding fabrication of welded

designs. Most examples are from energy and nuclear industry.

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Multi-pass welding Courtesy SERCO

Multi-pass Welding Courtesy AREVA NP (Former FRAMATOME)

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SPOT WELDING

Resistance spot welding is an efficient process to join vehicle body parts. This process involves strong

interactions between electrical, thermal, metallurgical, and mechanical phenomena. With the coupling

between electromagnetism, heat transfer, metallurgy, and mechanics, this process is accurately simulated

with SYSWELD.

This numerical approach makes it also possible to account for the evolutions of the contact surfaces. The

electro-thermal contact conditions are affected on a macroscopic scale by the evolution of the contact

surfaces but also on a microscopic scale in the evolution of electro thermal contact resistances.

Comparison between numerical (Blue and Red line) and experimental nugget size at the end of

heating

It is important to note that this simulation can be considered as a local model and repeated several times

on a global model by using local global approach. The main interest is to analyze and optimize, with very

short computation time, the welding sequences in order to reduce on the global distortion.

A Spot Welding Wizard has been developed to simplify the set up of spot welding simulations.

Workflow of the Spot Welding Wizard

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There is no particular limitation in the possibilities to simulate spot-welding fabrication of welded designs.

Most applications are from Automotive Industry.

Spot welding simulation and validation

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DISTINCTIVE COMPETENCE

GENERAL FEATURES

A complete welding simulation solution

Development team with more than 100 years of experience in welding simulation

All available welding simulation methods widely validated by Science and Industry, also for large

structures (see The Welding Simulation Solution)

Shrinkage, local-global and transient methods

State of the art meshing (VISUAL MESH) with all usual CAD interfaces

State of the art post-processing

WELDING DEDICATED GENERAL CAPABILITIES

Welding material database, definition of properties in Microsoft Excel

Welding heat source database for ARC, Laser and Electron Beam Welding

Dedicated Graphic User Interfaces to set up all available welding simulation methods

Five different methods to simulate the heat effects of welding: Transient, steady state, macro

step, local-global and shrinkage

Chaining with sheet metal forming and crash simulation

Toolbox CD with tutorials covering all welding methods and meshing

Engineering guide covering all aspects of weld modeling

Extended Welding User Guides, including expert knowledge (how to model welding, frequently

asked questions, quick checklist of welding simulation projects etc.)

Dedicated welding training courses

WELDING DEDICATED MESHING

Automatic generation of local models

Solid and / or Welding Macro Element insertion along weld paths based on shell meshed

components and 1D meshed trajectories

Automatic detection of to be welded components

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Automatic detection of the link between trajectories and components

GUI driven comfortable positioning of the cross section of the to-be-inserted 3D welding joints

Automatic extrusion or block methods to insert the 3D welding joints along the weld path

Automatic re-meshing of shell meshed components in order to generate a compatible mesh

between 3D joints and components

Export of shell- or shell-solid meshes for transient, macro step or WME based analysis.

GENERAL SOLVER CAPABILITIES

All options of nonlinear heat transfer, including melting, solidification and phase transformation

enthalpy

All options of nonlinear mechanics, including contact

Birth and death of elements

All options of programming (solver command language, simplified Fortran, Fortran, SYSTUS

interface language)

Many programmable user functions for arbitrary purposes

User defined subroutines, for user defined material laws, element formulations, and many other

purposes

WELDING DEDICATED SOLVER CAPABILITIES

All hereafter-listed capabilities are available for 2D Generalized Plain Strain, Axial-Symmetric, 3D

Solid, Shell, and Shell-Solid computation options, both for thermal-metallurgical and

mechanical-metallurgical computations, including chemistry. Available are linear and parabolic

element shape functions.

Welding and heat treatment dedicated macro language for the generation of welding project

files. It allows a quick integration of the solver in any graphic or data management environment

(for example MS Excel ). This language is one level more general as the usual command

language.

Power input managed through moving heat sources

Predefined heat sources for standard welding tasks

Programmable heat sources

Movement of heat sources along arbitrary paths in space

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Orientation of heat sources in space with reference lines

Automatic management of the heat source movement through start time, end time or velocity

Intensity function along weld-lines, to guarantee a mesh independent and constant power input

GUI supported check of the heat source operation and all heat source parameters

Variable stiffness definitions for surface elements in local reference frames, to simulate realistic

properties of clamping tools

Management of time stepping through practical welding process parameters

Automatic management of the linear system of equation solver and iterative technique (BFGS,

etc.)

All material properties depending on temperature, phases and chemistry

Direct coupling of temperature field and phase transformations in the element formulations

Many different phase transformation kinetics laws

Erase of material history above a user defined temperature, when heating

Birth of material history below a user defined temperature, when cooling

Management of yet to be deposited material through material law or birth and death

Automatic and mesh independent detection of the molten zone shape depending on the power

input

Possibility to mix different materials (laser welding of cast iron and low alloyed carbon steel

using an FeNi wire, to name an example)

Mesh independent management of melting and solidification, by material law.

Mesh independent application of temperature and phase dependent properties

Ideal plasticity, isotropic, kinematic and mixed hardening including phase transformations and

phase dependent material properties.

Dedicated Viscous-Plastic material formulation including phase transformations

Consistent tangent material matrix for isotropic, kinematic and mixed hardening, including

phase transformations

Transformation plasticity

Non-linear mixture of phase dependent mechanical properties

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Non linear geometry

Restoring of strain hardening during phase transformations

Particular linear tetrahedral element formulation to reflect best complex plasticity

Fully automatic solution process

Axial symmetric and 3D resistance welding (Coupling of Electrokinetics, Heat Transfer,

Metallurgy), mechanics including contact

DMP (Distributed Memory Parallel)

WELDING DEDICATED POST PROCESSING FOR TRANSIENT WELDING

Tracking of the evolution of the resulting yield stress of material

Tracking of the evolution of thermal strains (current position in the dilatometer)

Tracking of loads (temperature, thermal strains and phases) in the mechanical result file, to be

able to compare loads and results at the same time in multi-window displays

Comparison of variants

Separation between accumulated plastic strains of alpha and gamma phases

Tracking of the evolution of accumulated plastic strains in the alpha phases after transformation

FAST SHRINKAGE METHODS

The WELD PLANNER offers in a dedicated graphic user interface a fast shrinkage method that

allows shop-floor engineers, designers and planners distortion engineering of large and complex

components within one day

Validated with major German OEMs and suppliers

LOCAL GLOBAL DEDICATED GRAPHIC USER INTERFACE AND SOLVER CAPABILITIES

Local-global method packaged in a GUI usable by practitioners (PAM-ASSEMBLY)

Local Model generation packaged in a GUI usable by practitioners (VISUAL LOCAL MODEL ADVISOR)

Welding Macro Element technology to simulate the local-global approach (unique technology to

transfer inner forces between local and global models, shell behavior (6 DOF) in the Welding

Macro Element area).

Fast local-global method for huge structures

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Local model database including data base management

2D and 3D local models

Local models including multi-passes

Extrusion and block method for the transfer of inner forces between local and global models

Fully automatic transfer of inner forces between local and global model

Sequence and clamping manager

Tacking modeling

Sub-assembly modeling (taking into account an initial defect)

WELDING DEDICATED GRAPHIC USER INTERFACES

VISUAL WELD and WELDING ADVISOR to set up classic transient, macro step and steady state

welding projects

Enhanced WELDING PROJECT CHECKING TOOL

HEAT SOURCE FITTING TOOL to calibrate the heat source

VISUAL WELD for shop floor and planning. Dedicated to applications of contiguous welding in

Commercial Vehicle, Automotive and Aerospace Industry. Enables a complete welding task

definition. Meshing, post-processing and solver run.

HARDNESS COMPUTATION WIZARD

PHASE TRANSFORMATION CALIBRATION TOOL to adjust CCT and IT diagrams

MULTI-PASS WELDING ADVISOR to manage automatically the welding of hundreds of passes

SPOT WELDING ADVISOR to manage automatically the resistance welding of up to 9 sheets with

different material and sheet thickness

MS Excel based WELDING MATERIAL DATA MANAGER

VISUAL LOCAL MODEL ADVISOR, to manage the computation of local models

PAM-ASSEMBLY to manage welding assembly simulations based on the local-global method

VISUAL MESH, state of the art meshing tool with all usual CAD interfaces.

CHAINING WITH SHEET METAL FORMING

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Automated transfer of quantities between sheet metal forming and welding, in both directions

Transfer of quantities managed between different material laws, shell element formulations and

incompatible meshes

Mapping of quantities between different mesh shapes and mesh types

Transfer of component shape, sheet thickness, accumulated plastic strains and stresses

Particular methodology to manage the transfer of quantities between shell and solid elements,

for the purpose of tailored blank welding and stamping

CHAINING WITH HEAT TREATMENT FOR POWER TRAIN APPLICATIONS

All kinds of power train heat treatment, like surface heat treatment, through hardening and

case hardening

Turning of heat treated parts

Mounting of heat treated parts with press fitting

Welding of mounted and heat treated parts

In-service behavior simulation (maximum rpm, external loads etc.)

GETTING VALUE

GENERAL OBJECTIVES

The general objectives that can be achieved with The Welding Simulation Solution are

Market effectively

Reduce costs

Shorten time to market

Reduce downtime

Improve productivity

Increase efficiency

Improve profitability

Gain access to new, global markets

Enhance product quality and reliability

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Introduce innovation

Reduce weight

Reduce scrap and rework

Avoid failure

The Welding Simulation Solution has been designed to get value with respect to the listed

objectives, though computer modeling.

INDUSTRIAL BENEFITS

Using The Welding Simulation Solution, you will be able to

Minimize production cost

Minimize structural weight

Keep distortion within tolerances (distortion engineering)

Develop a weld plan

Minimize product risk in the earliest stage of the product development cycle

Master assembly problems

Ascertain the level & distribution of stresses

Control and minimize hardness and grain size in the fusion- and heat affected zone

Avoid cold cracks

The Welding Simulation Solution helps you to

Improve the product design

Identify better processes or materials

Meet procedure approvals

Meet product acceptance standards

Implement new production methodologies

Meet contract quality requirements

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Your objective to provide the best product possible is achieved by simulation-based process design through

Improved understanding of the effects that lead to distortions and stresses

Subsequent optimization of the product design and the manufacturing processes

A key feature of The Welding Simulation Solution is the sensitivity analysis. The sensitivity parameters

studied are

Welding process itself

Welding process parameters

Process stability (gap)

Welding sequence

Number and length of welding joints

Position of welding joints

Clamping conditions

Design

Material properties

Material combinations

Weld Quality

IMPROVEMENT OF THE PERFORMANCE AND QUALITY OF THE PRODUCT

Controlling material characteristics via the computer can significantly enhance the

performance and quality of a product. Controlling stresses via the computer can

significantly enhance the quality and structures service life.

Stresses control via modeling can:

Reduce weight

Maximize fatigue performance

Lead to quality enhancements

Minimize costly service problems

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The Welding Simulation Solution was specifically developed for this purpose. It offers all existing Finite

Element based methodologies to control material exposure, microstructure and stresses via the computer.

DISTORTION ENGINEERING COST REDUCTION

Designing the welding fabrication via the computer to minimize or control distortion can significantly

reduce fabrication costs.

Fabrication design via modeling can:

Eliminate the need for expensive distortion corrections

Reduce machining requirements

Minimize capital equipment cost

Improve quality

Permit pre-machining concepts to be used

The Welding Simulation Solution was specifically developed for this purpose. It offers all existing Finite

Element based methodologies to control welding fabrication via the computer.

POSITION IN THE PRODUCT CYCLE

The Welding Simulation Solution is placed at the earliest stage of the product cycle to

Study distortion influencing parameters in material, process and design

Take preventive measures for low-distortion welding constructions

Avoid over-dimensioning

The Welding Simulation Solution is placed at the earliest stage of the product cycle to choose the best

Welding process

Type of welding joint

Number and length of welding joints

Sequence and welding direction

Clamping conditions

The Welding Simulation Solution is placed at the earliest stage of the product cycle to

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Choose the best design dimensions regarding cost and weight

Make the design decisions taken more safer

Minimize post-design costs by avoiding failure or repair at a late stage of the product

cycle

Understand the physics which lead to distortions, stresses, material exposure and

failure during in-service behavior

Derive or improve design rules from sensitivity analysis

Understand the differences between adjustment-specimen and real parts

Improve established production processes

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GETTING DETAILED INFORMATION FOR R&D

The Welding Simulation Solution Booklet

This document contains extended information on the simulation of the heat effects of welding and the

coupling with other simulation disciplines, for example:

Applications (on more then 30 pages)

Scientific Work (on more then 20 pages)

Available Software Tools

Available Engineering Tools

Documentation

Key Technology

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Chaining with Stamping and Crash Simulation

Chaining with Fatigue and Structural Analysis

Joining of Large-Scale Structures

Available Simulation Methodologies

Training Courses

And much more