CalculiX comparabilities with SAP2000 and Analytical Calculations in Analyzing

Reinforced Concrete 3D Frame Structure

Project MembersSameer Alam (10-PWCIV-3457)

M. Bilal Qazi (10-PWCIV-3444)

Shad Muhammad (10-PWCIV-3449)

SupervisorAsst. Prof. Faisal-ur-Rehman

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Content● Introduction

● Problem Statement

● Objectives

● Literature Review

● Methodology

● Expected Outcome

● Work Overview

● Project Time-line

● References

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Introduction

● Finite Element Analysis (FEA) is a numerical technique for

understanding behavior of structures.

● Commercial software are black boxes and proprietary i.e one cannot

see/modify the source code. It is difficult to acquire the output tailored

for research.

● Reliability of analysis softwares is required to be studied.

● To explore CalculiX - A free Finite Element Software, for the analysis

of Reinforced Concrete(RC) Frame Structures.

● To use a genuine and ethically legal software for analysis.

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Problem Statement● SAP2000, SAFE and ETABS are commercial and proprietary

softwares are less suitable for engineering research.

● A FEA software for CED is required that can be modified and

developed as per our own requirement.

● Remember, all softwares provide disclaimer and provide no

guarantee on accuracy and reliability of results.

● Hence we require, 'a comparative analysis of CalculiX, analytical

and commercial FEA software by using example of RC frame

structure to explore the capability of CalculiX'.

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Objectives

● Getting complete grasp over application of FEA to frame structures.

● Bringing forward & learning a new software “CalculiX”: which may

be more reliable and productive in structural analysis results.

● To create tables and graphs of comparative results.

● To test the effectiveness of using CalculiX.

● To lay out background for adopting CalculiX as a home grown

software for the Department of Civil Engineering, UETP.

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Mission Statement

To Develop a Free Structural Engineering software for the Department of Civil Engineering, UETP, which can be designed, modified and used

as per our own requirement.

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Scope

● Our major work will be carried out in CalculiX, while SAP2000

and manual calculation will be used for cross-check.

● To master SAP2000 and incorporating MATLAB as a tool for

data processing, to help us increase the results efficiency and

productivity.

● A case study will be conducted on a Warehouse of KPK FATA

Secretariat.

● We will only perform computational & manual analysis.

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Limitations

● Only frame structure will be worked out.

● No experimental testing will be conducting.

● Only one case study will be carried out.

● No design calculations and design reports.

● Only gravity and earthquake loads will be taken.

● Linear analysis

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Why Structure Analysis Softwares?

● More Efficient

● Entity Behavior Modeling

● Greater Flexibility

● Fewer Flaws

● Time saving

– For professional engineers, contractors and architects, structural analysis software is a time saver

● Peace of Mind

– A building project is stressful enough without worrying about integrated building codes, proper construction techniques, and architectural calculations

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CalculiX● A Free Software, Three-Dimensional Structural Finite Element

Program, designed to solve field problems.

● It can be used, shared, decoded and rebuilt “FREELY”.

● It’s a Multi-Physics software covering many scientific disciplines and

providing many analysis options.

e.g.

– Seepage under Dams

– Maximum stress in a para-glide

– Pipe Flow analysis, Channel Flow Modeling, Time History Analysis, etc.

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Literature Review

● Literature about Basics of CalculiX

● Analysis of Frames in SAP2000

● Analytical Analysis of Frame Structures

(Stiffness Method, Moment Coefficient Method, etc)

● Reference manuals and documentations of CalculiX

and SAP2000

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Methodology

● We will start our work with basic structural models and leading

towards 3D frame structures.

● We will use analytical methods to manually analyze the 3D 2-Storey,

3 Bay frame model

(Stiffness Method, Moment Coefficient Method, etc)

● Analyze frames in SAP2000

● Analyze same frame in CalculiX

● Finally, comparing the results of both softwares and manual

calculations by using a case study.

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Expected Outcome

● We will get the comparative results in graphical & tabular

form for frame structure analysis in CalculiX & SAP2000.

● Percentage difference based on the result will be taken.

● Conclusions and recommendations will be provided.

● A comprehensive documentation for analysis procedure

of 3D frame structure using CalculiX will be prepared.

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Work ProgressBasic Model of Beam in CalculiX

Fig. 1 Steps involved in Modeling and Analysis of a Cantilever Beam in CalculiX

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Work ProgressBasic Model of Cantilever Beam in CalculiX

1kips

10'

Location Loads (kips)

10' Distance 1

Fig. 2 Cantilever Beam in CaluliX

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Basic Model of Continuous 3-Bay Beam in CalculiX

Location Loads (kips)

Bay 1, Midspan 1

Bay 2, Midspan 1

Bay 3, Midspan 1

Fig. 3 Continuous 3-Bay Beam in CalculiX

1kips 1kips 1kips

30'

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Basic Model of Truss in CalculiX1kips

5'

5'

Location Loads (kips)

At Joint #2 1

Fig. 4 Truss example in CalculiX

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Basic Model of Cantilever Beam in SAP2000

Fig. 5 Shear Force & Bending Moment Diagrams of Cantilever Beam in SAP2000

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Basic Model of Continuous 3-Bay Beam in SAP2000

Fig. 6 Shear Force & Bending Moment Diagrams of Continous 3-Bay Beam in SAP2000

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Basic Model of Truss in SAP2000

Fig. 7 Axial Force Diagram of 2D Truss in SAP2000

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Basic Model of 2D-RC Frame Structure in SAP2000

Fig. 8 Shear Force & Bending Moment Diagrams of 2D RC Frame Structure in SAP2000

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Manual Calculations Result2D-RC Frame Structure using Stiffness Method

Fig. 9 2D-RC Frame Structure using Stiffness Method

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Manual Calculations Result2D-RC Frame Structure using Moment Coefficient Method

Fig. 10 2D-RC Frame Structure using Moment Coefficient Method

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Finalized 3D-RC Frame Structure will Look Like following...

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Project Overview

● We performed the analysis of basic structures and structural

elements i.e Beams, truss and frames in SAP2000 & manually.

● Having a difference in results up to 7 to 8%.

● Solved 3 examples (2 Beams, 1 Truss element) in CalculiX &

SAP2000.

● We have made a GUI based on parametric solution for

automatic calculation for CalculiX having a simple GUI

(Graphical User Interface).

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Next Tasks● MATLAB interface

● Slab analysis

● 3D Frame analysis

● Lateral earthquake loading

● Interface for parametric inputs

● Custom output formats

● Importing/exporting models to SAP2000

● Creating analysis report

● Documentation of all the processes

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Project Time-line: Gantt Chart

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Weekly Meeting ScheduleDate Day Task Name Student Status

13/09/13 Friday Literature review on CalculiXM. Bilal Qazi

Sameer Alam Shad Muhammad

Completed

20/09/13 Friday 2D RC-Frame Structure analysis in SAP2000 Sameer Alam Completed

26/09/13 Thursday Manual Calculations & analysis of 2D RC-Frame structure M. BilalShad Muhammad

Completed

05/10/13 Saturday 1st Presentation Preparation Shad Muhammad Completed

04/10/13 Friday Presentation Review & Delivery PracticeM. Bilal

Sameer Alam Shad Muhammad

Completed

31/10/13 ThursdaySimple Beam analysis in CalculiX

M. Bilal QaziSameer Alam

Shad Muhammad

Completed

05/11/13 TuesdayTruss, cantilever beam & 3 Bay beam example in Calculix

M. Bilal QaziSameer Alam

Shad Muhammad

Completed

27/11/13 Wednesday Recheck of manual calculation using MATLAB M. Bilal Qazi Shad Muhammad

Completed

15/01/14 Wednesday Working on Project Copy Sameer AlamShad Muhammad

In progress

21/02/14 Friday Automating Calculations in Octave Shad Muhammad In Progress

04/03/14 Tuesday 2nd Presentation Preparation M. Bilal Qazi Sameer Alam

Completed

05/03/14 Wednesday Presentation review Shad Muhammad Completed

10/03/14 Monday Making and interface based on Parametric Procedures Shad Muhammad In progress

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References

● CalculiX USER'S MANUAL

(www.bconverged.com/calculix/doc/cgx/html/index.html)

● Getting Started with CalculiX (www.bconverged.com/content/calculix/doc/GettingStarted.pdf)

● SAP2000 Tutorial Manual - Extra Materials

● Tutorial to SAP2000 Student Edition

● Stiffness Method details

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THANK YOU

Special Thanks to

Sir Faisal-ur-Rehman for his hard work &

cooperation