Control technologies/CADCAM

Reprinted from International Sheet Metal Review May/June 2006

Simulated sheet metal forming operations have improved

product quality, reduced body component lead time and

married a more distinct, attractive design with improved manufacturability

at Volvo Cars Body Components’ plant in Olofström, Sweden.

ISMR SAYS:

Volvo Cars’ designers and engineers have allied form and function with

speed and precision in the development, production and delivery of car

body components – using simulation techniques to achieve their goal

Form and fuIn Sweden, roughly one in everyfive cars sold is a Volvo. In 2005,the Swedish manufacturer sold a

total of 443,947 cars to over onehundred countries.

Volvo Cars head office, productdevelopment, marketing and admi-nistration are all based in Göteborg,Sweden. Its final assembly facilitiesare in Göteborg, Ghent (Belgium)and Pininfarina in Uddevalla. Mostof the car body components arestamped at Volvo Cars BodyComponents in Olofström andGöteborg. Volvo Cars is currentlyto start local automotive produc-tion in China – the new Volvo S40will be built at Volvo Cars’ partnerChangan Ford’s production plant inChongqing.

Volvo Cars has been a whollyowned subsidiary of Ford MotorCompany since 1999 and is part ofthe Premier Automotive Group(PAG) with Jaguar, Land Rover andAston Martin. Volvo Cars is also aCentre of Excellence for Safety forFord Motor Company and a Centreof Excellence for Telematics forPAG.

ISMR was invited to its 291,314m2 plant at Olofström, 150km northeast of Malmö, which producesapproximately fifty million car bodycomponents per year. In 2005,Olofström consumed 400,000tonnes of sheet metal, deliveringcar body components by train andcontainer to various plants and cus-tomers.

New launches and requirements

With a vision to be recognised asthe most competitive stampingoperation delivering high quality carbody components through a robust,lean and environmentally-friendlyproduction process, Volvo CarsBody Components at Olofströmhas, with the smart use of metalforming simulation techniques,improved the manufacturability ofVolvo Cars’ distinctive design andreduced costs and part lead-times.

Volvo Cars Body Componentsuses mainly mechanical presses andhas twenty press lines, two transferpresses, one power press and fivecoil-fed presses. It is also in theprocess of constructing a new

Volvo Cars Body

Components’ plant in

Olofström, Sweden

Volvo Cars Body

Components has

twenty press lines

hydraulic press line which shouldstand ready in the end of 2007.

The Olofström plant deliversbody components mainly to VolvoCars’ final assembly facilities inGöteborg, Ghent and Uddevalla. Italso delivers components to Ford ofEurope and PAG.

“We produce panels and subassem-blies for two body-in-whites perminute,” said Anders Skogsgårdh,manager, Engineering StampingCAE, at Volvo Cars BodyComponents. “Ten car models arecurrently in production and thereare approximately two new car pro-jects per year. It is unique to have somany models in the same press shopat the same time and we makeextensive use of forming simulationto early secure manufacturability,reduce lead times and costs.”

Sheet metal forming simulation

Core processes for Volvo CarsBody Components include manu-facturing engineering, tooling and

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Control technologies/CADCAM

nction

Reprinted from International Sheet Metal Review May/June 2006

robustness evaluations. “Some car manufacturers distin-

guish between simulation and finalvalidation and they like to have twoor three different software codes forfinal validation but we only useAutoForm,” commented KristofferTrana, senior forming analysis engi-neer, Volvo Car Body Components.“We found that a multi-codeapproach was not good enoughbecause if we encounter problemsvery late in the developmentprocess, it may result in unnecessarylate changes.

the new car models in production.“From 2000, with big changes in

our workload and multiple pro-jects on hand, we made the deci-sion to just use AutoForm softwarefor sheet metal forming,” saidAnders Skogsgårdh. AutoForm’sIncremental, DieDesigner andSigma modules have allowedVolvo Cars Body Components toperform more accurate simula-tions, analyse more parametersand ensure many more loops and

Above right and

below: AutoForm

software has

enabled Volvo Cars

Body Components

to perform more

accurate

simulations

the production of body compo-nents (stamping, sub assembly andmaterial planning/logistics). TheStamping Engineering encompassesStamping CAE, Die ProcessEngineering and it liaises withStrategy and Concept, AssemblyEngineering, Geometry and theR&D/Design in Göteborg for newproduct development.

“There are forty people inStamping Engineering,” AndersSkogsgårdh told ISMR, “and sevenof us work in sheet metal formingsimulation.”

Volvo Cars Body Componentsuses AutoForm CAE software fordraw-die development/optimisa-tion, layout of trimming and flang-ing tools, detection of surfacedefects, calculation and compensa-tion of springback, optimisation ofmaterial usage etc. Pre-productionwork includes die development,simulated forming, analysis and themanufacture of the formed dies. Alot of dies are analysed to support all

Above (l-r):

Kristoffer Trana,

senior forming

analysis engineer;

Anders Skogsgårdh,

manager of

Engineering

Stamping CAE and

Dr. Mats Sigvant,

technology area

leader, FE-simulation

at Volvo Cars Body

Components

15

Sigvant, technology area leader, FE-simulation, Volvo Cars BodyComponents. “To be able toincrease production, we needed tobe better in the pre-production andsimulation phase to remove as manyproblems as possible before the cars

Reprinted from International Sheet Metal Review May/June 2006

Control technologies/CADCAM

Streamlining processes

Volvo Cars Body Components hasrecorded a huge increase in outputsince 2000, incorporating the pro-duction of the new S40/V50 (theold S/V40 was stamped at anotherplant) within its current press shop.

“We have made large steps inaccuracy with our simulationprocesses,” commented Dr. Mats

“AutoForm’s tooling/tryout solu-tion allows us to simulate moreprocesses,” added Trana. “We needhigh precision and we are con-stantly trying different processesand simulations to find a optimumbetween product attributes andmanufacturability. One indicatorfrom using sheet metal formingsimulation is that the quality of thetry-out and the body of the firstseries production car is so muchbetter than it was five years ago.Surface finish is also muchimproved. With increased volumesand focus on material utilisationthe nesting-module has becomemore important.”

Trana also points out the impor-tance of having core stamping expe-rience and sheet metal knowledgewhen performing simulations.

“The same engineer who does thesheet metal forming simulation isalso present at the tryout floor – thisis crucial because we can learn fromactual production, get vital feedbackand strive for improvement,” he toldISMR. “This means that there is realliaison between all the departments.”

Skogsgårdh agrees. “Simulation isa key enabler to shorten toolinglead-time and secure manufacturingrobustness. We can be assured ofreliable, lean stamping productiondue to stable forming processes,quality assured dies before die man-ufacturing and better/faster tryout,”he told ISMR. “We increase ourknowledge with each simulationand, in the process, gather correctCAD data for part and die, which isinvaluable for future projects.”

Above:

Die Design for die

manufacturing

Simulation result

from the new Volvo

S80 bonnet inner

Below: Forming sequence of the new Volvo

S80 bonnet outer

Left: Tooling and

high speed milling

at Volvo Cars Body

Components

16

come to production. We havestreamlined the process and loweredtryout times. We now have very fewproblems with forming dies sincethe simulation is working well, weare saving money and the results arerespected. The bottom line is thatpeople like simulations, they see thebenefit. It saves time and cost.”

In the pre-study stage, Volvo CarsBody Components simulates almosteverything – all line dies, transferdies and a lot of progressive dies. Diedesign for simulation is done inAutoForm-DieDesigner or Catia.Volvo Cars Body Components alsospecifies that contracted toolmakersmust use AutoForm software.

“Toolmakers send us their simula-tion files and we check and approvethem,” commented Dr. Sigvant.“We would have previously sup-plied our simulation model andmaterial database to the supplier.We then discuss the best way of pro-ducing the tool. Suppliers must pro-duce tools within safety margins forproduction. One of the benefitsfrom using simulation is to get bet-ter tools from third parties. We alsosupport R&D/Design in Göteborgwith feasibility studies for new carconcepts - different areas may haveto be modified using simulation.”

Material issues and challenges

Volvo Cars Body Components has along history of using high strengthsteel and aluminium – it was one ofthe first carmakers to use dual phasematerials in volume production andhas been steadily increasing its usageof this material over the last tenyears. It also uses a lot of tailoredblanks but has reached a maturelevel of consumption for these.

“Today, we have tougher materialsbut also quite tough requirements,”commented Kristoffer Trana. “Weneed to be aware of issues like spring-back. This means getting a pressedpanel from the draw die quicklywhile putting the other dies on hold.In this way, we can make correctionsto the draw die before we start spendtime and money on the followingdies. This is also an area where CAEsimulation is crucial.”

Anders Skogsgårdh agrees.“Simulation allows us more time

to spend on other processes and pro-cedures. We don’t have the time towaste – we go from one model toanother and there are limited time-frames, which is where good simula-tion tools are vital.”

“With some high strength steels,we can find springback problems,”commented Dr. Mats Sigvant.“Springback is a challenge and cangive different results. In tryout, thephysical material results can be dif-ferent so it is equally hard to handlein the virtual world.” Therefore, thespringback problem goes hand inhand with, and is very much relatedto, process robustness and materialproperties.

AutoForm is tackling the spring-back problem with a die compensa-tion package in a new version of itssoftware, and with its Sigma mod-ule, which was launched one and ahalf years ago.

“We also determine the materialdata for forming simulation in cor-poration with a research companybased in Olofström so that we havecontrol over the material datawhich is input to our simulationprocesses,” added Sigvant. “Thismeans that our database is con-stantly being updated with newmaterial data.”

Another key issue, such as mate-rial utilisation, can also be con-trolled using simulation software,which is particularly crucial in aclimate of high steel prices.

Volvo Cars has already adopted aworking method with upfront sim-ulation in its car programmes butfuture demands on lead-timereductions will reinforce this needeven further.

“We need to work even harderand be more dedicated with ourforming expertise and simulations inthe concept, pre-study and diedesign phase onwards,” Skogsgårdhtold ISMR. “We need closer collab-oration with our suppliers and weneed to continuously develop with afocus on four main areas – enhancedmaterials models (improved mater-ial data, failure criteria etc.), spring-back, surface defects and robust-ness.”

“Car bodies are becoming strongerand lighter,” he concluded. “We aimto develop processes with excellentmanufacturability that can meetVolvo Cars’ distinctive and attrac-tive exterior requirements, demandsand core values.” ISMR

Reprinted from International Sheet Metal Review May/June 2006

Control technologies/CADCAM

Above: Kristoffer

Trana shows ISMR

a simulation of a

Volvo car body

component

Right and below:

Analysis of surface

defects in simulation

and at tool

tryout/presshop

17