3DCS FEA Compliant Modeler - Finite Element Analysis and Tolerance Analysis

2. Dimensional Control Systems | 2017 All Rights Reserved Available in All 3DCS Platforms 3DCS FEA Compliant Modeler is an Add-on module available for all versions of 3DCS, including all integrated versions and the stand alone version (multi-CAD)

3. Dimensional Control Systems | 2017 All Rights Reserved Value of Compliant Modeler Increase the accuracy of your variation analysis by simulating the effects of clamping, welding and bending, or from gravity and thermal influence. ● Add variation from process and environmental forces to your model for a more comprehensive analysis. ● Design to account for process ● Optimize processes to reduce variation such as riveting sequences, clamps and bending.

4. Dimensional Control Systems | 2017 All Rights Reserved What is Compliant Modeler? Compliant Modeler is an add-on module for 3DCS Variation Analyst Software. Compliant Modeler uses mesh files from an FEA Preprocessor to simulate the effects on parts and materials from processes, both environmental processes like gravity and heat, as well as manufacturing processes like welding, clamping, bolting and riveting. Compliant Modeler solves the deformation as part of the variation analysis, adding the variation from deformation and process to the stack up. Using a Stiffness Matrix from a Solver, 3DCS simulates the deformation from the process in conjunction with your Variation Analysis.

5. Dimensional Control Systems | 2017 All Rights Reserved Reasons to Use Compliant Modeler Deformation in parts causing less accurate variation analysis results Over Constrained assemblies in the model Parts deforming or has more than 3 primary datums Clamping sequences and locations need optimizing Welding, bolting, riveting in the model Concentrated forces Springback issues Gravity, stresses or residual forces Thermal deformation causing variation in use or production

6. Dimensional Control Systems | 2017 All Rights Reserved Compliant Modeler Requirements Increased Hardware Requirements • 3DCS FEA Compliant Modeler adds advanced analysis in addition to the normal analysis. In order to keep analysis time down, higher level hardware specifications are recommended. Finite Element Analysis - FEA Experience • To generate the output files from the FEA Solver, experience with FEA Analysis is highly recommended. This will improve the accuracy of the files and analysis.

8. Dimensional Control Systems | 2017 All Rights Reserved One Software, Two Analyses One Software for the entire analysis: Apply your Finite Element Analysis (FEA) in the same tool as your variation analysis, determining any interactions and reducing the need for training in other solutions.

9. Dimensional Control Systems | 2017 All Rights Reserved Optimize Processes • Find the optimal weld, bolt or riveting sequence • Find the optimal amount of welds, bolts and rivets needed • Find the optimal placement of welds, bolts and rivets • Reduce variation as well as cost by removing unneeded processes

11. Dimensional Control Systems | 2017 All Rights Reserved Clamping, Welding, Bolting and Riveting One degree of freedom or all degrees of freedom can be constrained using clamp move ● Simulating Joint between 2 parts: > Spot Weld : > Bolting : > Fastener :

12. Dimensional Control Systems | 2017 All Rights Reserved Gravity 1. Released from tooling 2. Weight of parts move parts after manufacturing and assembly Example: Rear Fascia sags after released from tooling

13. Dimensional Control Systems | 2017 All Rights Reserved Thermal (Environment) Expansion from thermal effects in the environment or the function of parts (exhaust pipes) can cause variation and issues down the line. Simulate the expansion and variation caused by heat and how it affects your assembly.

14. Dimensional Control Systems | 2017 All Rights Reserved Over Constrained Parts ● Simulating an over constrained assembly: • A part deforms to another part • A part which has more than 3 primary datums • Can be simulated with Bend moves in 3DCS base software, using Compliant Modeler is approximately 14% more accurate.

16. Dimensional Control Systems | 2017 All Rights Reserved FEA Mesh Files Compliant Modeler allows the user to apply an FEA Mesh file to a part or multiple parts. • These need to be generated from an FEA Software. • The FEA Software is not needed for any analysis Once the Mesh file is applied to the part, Compliant Moves are added to simulate different kinds of processes and forces. The Deformation changes the nominal position, allowing further tolerance analysis stack ups to determine overall variation results.

17. Dimensional Control Systems | 2017 All Rights Reserved Process Flow – Model Creation CAD • CATIA • NX • Creo • Other (Multi-CAD) FEA • Abaqus Mesh File • Hypermesh Mesh File SIM • 3DCS Variation Analyst

20. Dimensional Control Systems | 2017 All Rights Reserved Process Flow – Model Creation CAD • CATIA • NX • Creo • Other (Multi-CAD) FEA • Abaqus Mesh File • Hypermesh Mesh File SIM • 3DCS Variation Analyst Load CAD Model into 3DCS Create and Export Mesh file - Material Properties Load Mesh and Apply to parts - Change nominal position

21. Dimensional Control Systems | 2017 All Rights Reserved Workflow Summary • Moves to Simulate Force • Utilize Finite Element Analysis Solver (FEA) 1. Model in CATIA V5 2. Create Mesh in Abaqus 3. Run Analysis in 3DCS

28. Dimensional Control Systems | 2017 All Rights Reserved Output Results (Changes to Gap) Measurement Effect of Gravity (mm) Effect of Thermal (mm) Total Variation (mm) M1 2.71 5.80 8.51 M2 2.28 4.60 6.88 M3 1.83 3.58 5.41 M4 1.79 3.40 5.19 M5 2.64 4.26 6.90 M6 2.25 3.52 5.77 M7 1.52 2.21 3.73 3DCS

30. Dimensional Control Systems | 2017 All Rights Reserved Mesh File Creation NOTE: Mesh file should be created by an FEA specialist. •You need an individual mesh file for each compliant part in the DCS model. One Part, One Mesh File •If modelling an assembly as one part then the mesh file needs to be created as an assembly with connections between parts in the assembly. If Assembly is 1 Part, Then Mesh Needs to be an Assembly •Number of nodes per part can be judged based on part geometry. Increasing number of nodes per part might increase the accuracy but can result in slower simulation time. More Nodes, More Accuracy, More Time Simulating Optimum mesh file size is 10mb or less. The part mesh file from an FEA pre processor does not need to have any boundary conditions. DCS creates boundary conditions.

31. Dimensional Control Systems | 2017 All Rights Reserved Modeling Best Practices First step is creating the whole model including all MTMs! (Moves, Tolerances, Measures) Build Rigid Body First  Then Add Compliant Moves

32. Dimensional Control Systems | 2017 All Rights Reserved Modeling Best Practices ● While writing compliant moves, all compliant parts should be fully constrained before doing any further operation such as Weld, Forces, Thermal, Gravity etc. A part can be fully constrained using: o One point in a Hard/Coincident Clamp Move (using 6dof FEA files) o Three points in a Hard/Coincident Clamp Move (using 3dof FEA files) o 6 points in a Soft Clamp Move. o Position 3 points(1 point in 6dof) having x, y & z checked. ● It is recommended not to mix and match Hard and Soft clamp in one move.

33. Dimensional Control Systems | 2017 All Rights Reserved Thermal Best Practices If simulating thermal deformation, create your thermal move and pick all the points that have a thermal deformation and input the change in temperature. Check the thermal move section in help file to understand the difference of having a thermal deformation on whole part and on some points on the part.

34. Dimensional Control Systems | 2017 All Rights Reserved Clamping Best Practices While unclamping/unpositioning, need to make sure the assembly/parts are still fully constrained after unclamping/unpositioning. When simulating a multi-stage assembly, unclamping must be a 2 move process. In the first move you unclamp all but the points needed to fully constrain the assembly and then use Skip Deformation option in an Unclamp Move for remaining clamps. Skip Deformation option removes the clamps from the software memory but does not deform the part. Skip Deformation Unclamp Move should be the last move in the 1st fixture stage.

35. Dimensional Control Systems | 2017 All Rights Reserved FEA Mesh Creation Best Practices Make sure the FEA files are supported by stiffgen/Compliant Modeler! Refer to help file for supported files. Product Mesh File Extension Stiffness Matrix Extension Abaqus .inp .mtx Nastran .bdf, .blk, .dat, .nas .bdf Optistruct .fem, .parm .dmig MSC Nastran .dat .pch

36. Dimensional Control Systems | 2017 All Rights Reserved FEA Mesh Creation Best Practices ● Make sure consistency of units is maintained while creating the mesh file. For reference to consistency of units see the DCS help file. ● If using Stiffgen to create the FEA files then select the mesh file units in stiffgen. ● If you have multiple FEA solvers available on your machine, make sure to select the same FEA solver that was used as a pre-processor for creating mesh file. ● It is recommended to create 6 Degree of Freedom (DoF) FEA files for a shell mesh. ● You can only create a 3 Degree of Freedom (DoF) FEA file for a solid mesh.

37. Dimensional Control Systems | 2017 All Rights Reserved FEA Mesh Creation Best Practices ● Select Mass Matrix/Thermal load option in stiffgen if you have Gravity or Thermal Expansion resp. in your model. ● It is recommended to always have a 6 Degree of Freedom (DoF) thermal load file for shell mesh. ● Once you hit Generate FEA Files, make sure the batch process ran successfully and the files were generated. If you see an error then check the .dat or .msg files in the dcsFEA_DATA folder for any error messages. For Thermal / Gravity

38. Dimensional Control Systems | 2017 All Rights Reserved Nominal Build Best Practices 1. Create the Input FEA Data move and select all the compliant parts and corresponding mesh/stiffness files in it. Move it above all the compliant moves in the tree. 2. Deactivate all the compliant moves and hit nominal build and check all the DCS points are linked to FEA nodes using FEA Point Linking Wizard. 3. If everything looks good, activate all the compliant moves and hit nominal build again. 4. If you have any unrealistic deformation of points in the model, make sure to check the consistency of units in FEA files.

40. Dimensional Control Systems | 2017 All Rights Reserved Over Constrained Assembly ● Model 1: Two piece rail model ● Objective: Simulate an over constrained assembly taking into account Manufacturing Process and Gravity to calculate: o Spring back due to manufacturing process. o Deformation o Reaction Forces

41. Dimensional Control Systems | 2017 All Rights Reserved Results Nominal Build Rigid Body Gravity Weld 1 Unposition Clamp Base Force Weld 2 Unclamp Gap(mm) 5.00 3.75 3.83 3.75 0.00 0.00 0.00 4.80 Reaction Force(N) 0.00 4.01 3.55 3.94 8.46 9.13 22.26 0.32 2000 Sample (Range) Gap(mm) 4.75

42. Dimensional Control Systems | 2017 All Rights Reserved Exhaust Pipe ● Model 2: Exhaust Pipe ● Objective: To simulate the effect of change in temperature to calculate deformation. Measurement Deformation(mm) M1 5.58 M2 5.57 *All of these calculations include component and assembly dimensional variation

46. Dimensional Control Systems | 2017 All Rights Reserved 1. Front 2. Mid 3. Mid2 4. Upper Determine the location of lowest flush variation between Hood and Fender. Simulate the placement of Bumpers at (4) locations:

50. Dimensional Control Systems | 2017 All Rights Reserved 1. Front 2. Mid 3. Mid2 4. Upper 2.173 mm 2.172 mm 2.305 mm 2.328 mm 2.483 mm0. None Mid2 bumper location is best for Hood to Fender flushness.

3DCS FEA Compliant Modeler - Finite Element Analysis and Tolerance Analysis

Benjamin Reese

3DCS FEA Compliant Modeler - Finite Element Analysis and Tolerance Analysis