1 Tolerance Analysis of Deformable Assembly CATIA Training Exercises Version 5 Release 8 March 2002 EDU-CAT-E-TAA-FX-V5R8

2 Modify the External and Temporary paths in Tools, Options, Analysis & Simulation, Tolerance Analysis, General. Change for a disk where there is enough space to avoid storage problems. Check that the material is under the part in the tree, and not under the product component. Furthermore, you must do External Views on your parts as the case may be. Preliminaries

3 Introduction to TAAp.5 The Process Product Resource conceptp.6 Presentation of TAA productp.7 Data loadingp.8 Supports and mechanical joints creating p.9 Positioning systems creatingp.10 Fastening and contact creatingp.11 Annotations creatingp.12 Activities creating and items assignmentp.13 Computing and results visualizationp Plates assembly Interactive Tolerance analysisp.15 Process presentationp.18 Supports and Joints creationp.19 Positioning systems creationp.22 Spot Welding and Contact creationp.25 Deviations creationp.28 Activities creationp.31 Computation and results visualizationp.33 Table of Contents (1/2)

4 2. Parts assembly Tolerance analysisp.36 Load a product and TAA data p.39 Understand the text file inputsp.41 Study of the first positioning activityp.43 Statistical analysisp.45 Add supports and joints by the text filep.49 Replace a positioning system interactivelyp.52 Replace a positioning system by the text filep.54 Analyse and comparep.56 3.V4 Mesh assembly Tolerance analysisp.59 Load data from the text filep.62 Understand the text file inputsp.64 Compute and visualize resultsp.66 Run a sensitivity analysis p.70 Modify a deviationp.72 Replace a positioning systemp.74 Resumep.77 Hints and Tipsp.80 Table of Contents (2/2)

5 Introduction to TAA In this lesson, you will learn about the Tolerance Analysis of Deformable Assembly Workbench by : Process Product Resource concept Main functionalities

6 Introduction to TAA : P.P.R. concept We can also have access to all TAA data created or imported, at the end of the tree. Resources : Contains supports as assembly on tooling, and reference points. Product : Contains the assembly components and the parts which contain reference points. Process : Contains the different activities of the process (Positioning, Fastening and Release)

7 Data loading 1 Computing and Results visualization 6 Activities creation and items Assignment 5 Import mesh Import Data Import Product Annotations creation 4 Fastening and Contact creation 3 Supports, Joints and Positioning systems creation 2 Introduction to TAA : Main functionalities

8 Open a new process. Import assembly components : You can work from model files. You can import data from a text file (components and/or TAA data). You can import a product. First steps: open a new process and load data. Introduction to TAA : Data loading

9 Supports Rigid support Flexible support Mechanical joints The next step is the creation of supports and mechanical joints. 1. Give a name 2. Select TasResources in the tree 3. Select a point or a node 3. Select the assembly component 4. Select a support 1. Give a name 5. Select a point or node 2. Choose a type Introduction to TAA : Supports and mechanical joints creation

10 Positioning systems Once the mechanical joints are created, we can regroup them to create positioning systems. 3. Keep per default, tighten or release mechanical joint degrees of freedom 2. Select a set of mechanical joints 1. Give a name Introduction to TAA : Positioning systems creation

11 Fastenings Spot Welding Riveting Bolting Spot glueing Contacts Contacts are generally applied around Fastening points to avoid clash problems. Next, w e can apply fastenings depending on the process. 3. Select the common point or node 2. Select components to fasten together 1. Give a name 3. Select the common points or nodes from a single component 2. Select the components in contact 1. Give a name Keep the same name and components for multi selection Introduction to TAA : Fastening and contact creating

12 Input deviations They are applied on an assembly component, and are obtained from measurements. Output deviations They are applied on the whole assembly, and correspond to target values which will be compared to input deviations. Annotation bag It contains annotations set. We can apply input deviations on each assembly component, and output deviations on the whole assembly. 2. Select the component 1. Give a name 3. Select the positioning system for measurement 4. Select the point or the node Introduction to TAA : Annotations creation

13 Create an activity Positioning Fastening Release Assign/Unassign items Link the activities We can define the process activities, choose their order and assign them items. 1. Assign positioning systems 2. Assign fastenings 3. Assign Annotations bags You can link the activities. Introduction to TAA : Activities creation and items assignment

14 Compute an activity Visualize results Analysis results We can compute tolerance analysis on given activities, and visualize displacements or residual stresses. Sensitivity analysis can also be done. Choose the type of computing. Only Pre-processing just for meshing. If you select the last activity, all the process activities will be displayable. Generate a report Select displacements or residual stresses visualization Select the activity Choose a determinist or a statistic visualization Select determinist or statistic results. Select deviations or forces Select the activity Choose a sensitivity analysis and reframe automatically on the chosen element. Output deviations which are in the activity annotations bag Introduction to TAA : Computing and visualization

min. Master Exercise 1. Plates Assembly Interactive Tolerance analysis In this exercise you will learn how to compute a tolerance analysis in an interactive way. Skills needed : Creating Supports, Joints, Positioning Systems, Welding Points, Contact, Deviations, Activities. Launching a Computation Displaying Results

16 Creating Positioning Systems, Welding Points, Contacts, Deviations and Activities. Launching a Computation. Displaying results. Design Intent : Interactive Tolerance analysis

17 Design Process: Plates assembly Interactive Tolerance Analysis Model files loading 1 Positioning systems creation 2 Welding Points and Contacts creation 3 Deviations creation 4 Activities and assignations creation 5 Compute and display Results 6

18 Process Presentation

19 20 min. Master Exercise Interactive Tolerance Analysis : Supports and Mechanical Joints creation Tasks to complete : Load model files. Apply Supports on nodes. Apply Mechanical Joints on supports.

20 First, we need to load meshes and create Supports. Open a new process. Import meshes. Select the import mesh icon. Select the product in the tree. Choose the model file, and repeat for the other one. Create Rigid Supports. Select the TasResources object Create support nodes by selection (12 nodes). (Rk: 12 rigid supports for 12 nodes) Load : Plate.model Load : Curved Plate.model 12 Supports (6 for the curved plate And 6 for the plate) 8 elements + Do It Yourself (1/2)

21 Once the supports are created, we can apply Mechanical joints. Create Mechanical Joints selecting Supports previously created. 1/ Select the curved plate as first component. 2/ Select the Rigid Support. 3/ Choose a Spherical (3 rotations allowed), an Annular-Linear (3 rotations and 1 translation allowed), and a Point joint type (5 d.o.f.) for the three first supports. 4/ Choose Point joint type for the three last supports in the middle of the part. Repeat this sequence for the Plate part. Spherical Point Annular-Linear Point Do It Yourself (2/2)

22 20 min. Master Exercise Interactive Tolerance Analysis : Positioning Systems creation Tasks to complete : Choose the joints to regroup. Create Positioning Systems depending on process activities.

23 A Positioning System represents a set of links used to support or to tight a part of an assembly. Positioning Systems for Positioning Activity (positioning of the two parts in our case) 1/ Select the Positioning System icon. 2/ Select the six mechanical joints created before from the Curved Plate part (all the different types of joints must form at least an isostatic set). Call it PositionSys1. 3/ Repeat these operations for the Plate part and call it PositionSys2. There may be one Positioning System for each use : Positioning System for each part used for the process activities ( part tightened or not). Positioning System for Fastening activity. Positioning System for the Release activity. Positioning System for each part used for the deviations measurement. You can select joints from the tree or directly on the part. Do It Yourself (1/2)

24 Positioning systems for Fastening Activities We will create same positioning as the previous positioning systems PositionSys1&2. But, we fasten all DOF except Rx, in selecting Tightening option, on one point (generally on a Point type). Call it PositionSys3 & PositionSys4. Positioning systems for Release Activity : We will use the PositionSys1. It means that since both components are welded each other, we release Curved Plate component. Positioning Systems for the deviations measurement : 1/ For Curved Plate : we will use PositionSys5. 2/ For Plate : create PositionSys6, based on PositionSys5 model for the Plate part. Rx must be always released because parts welded together are supposed to move unrestrainedly around the X axis, normal to plane by convention. Clamped point Do It Yourself (2/2)

25 10 min. Master Exercise Interactive Tolerance Analysis : Welding points and Contacts creation The parts will be welded together : Apply Welding Spots. Apply Contacts around Welding points, to prevent assembly components to clash near a fastening element.

26 1/ Click on the Spot Welding icon. 2/ Select the two parts to weld together. 3/ Select the welding spot nodes. 4/ Repeat the sequence for the two other welding points. If there are several superposed points or nodes (like here), select just one of them. A blue welding symbol appears at the welding point. A Spot Welding icon appears in the tree. Do It Yourself (1/2)

27 1/ Click on the Contact icon. 2/ Select the two parts to apply contact. 3/ Multi select the 8 contact nodes. If there are several superposed points, select just one of them. A green contact symbol appears at the contact point. A Spot Welding icon appears in the tree. Contact links are generated between contact points and spot welds. Contact are used to prevent clash problems between parts because of deformations. They are generally applied around fastening points. Do It Yourself (2/2)

28 20 min. supports deviations Spot welds Master Exercise Interactive Tolerance Analysis : Deviations creation We will apply the two main Deviations types : Input Deviations which are measured tolerances on one single part of the assembly. Output Deviations which are target tolerances applied on the product, used to compare final results.

29 Input deviations 1/ Select the deviations icon and choose the Curved Plate component. 2/ Select the Positioning System created for the deviations : PositionSys5. You may activate Set parameters as default for a faster selection (V5R8SP1) 3/ Select a deviation node on the Curved plate mesh (see next slide). 4/ Deviation is showed by a white arrow and statistic values. Repeat for the others nodes (7 deviations by part). 5/ Repeat for the Plate component (with PositionSys6). Mean = 1 Standard Deviation = 0.10 Do It Yourself (1/2)

30 supports deviations Spot welds Do It Yourself (2/2)

31 20 min. Master Exercise Interactive Tolerance Analysis : Activities creation We will create the different activities presented at the beginning, and assign them items : Create activities. Assign Positioning systems and Spot Welding. Link all the activities together.

32 Select Positioning Activity icon. Select the Process icon in the tree. Select Fastening Activity icon. Select the Process icon in the tree. Repeat two times for the others SpotWelding activities. Select Release Activity icon. Select the Process icon in the tree. Select Item Assignment icon. Select PositionSys1, and then the Positioning.1 activity created previously. Repeat with PositionSys2. Do the same for the Fastening.1 activity, and add a SpotWelding by selecting it in the tree or on the geometry. Repeat for the others Fastening activities. Assign the PositionSys1 for the Release activity. Choose the Open PERT Chart icon. Reorder and link the different activities. Do It Yourself

33 15 min. Master Exercise Interactive Tolerance Analysis : Computation and Results Visualization We will show how to compute a simple Tolerance Analysis : Compute an analysis. Visualize displacements for each activity.

34 Compute an analysis. Select the last activity so as to have the possibility to visualize all the process activities. Visualize displacements for each activity. Clashes visualization may be a deformation scale factor effect. Do It Yourself

35 Fundamental Steps Create Positioning Systems : Create supports and mechanical joints on nodes. Regroup joints and create positioning systems. Create Welding Spots and contacts : Create welding spots on nodes. Create contacts around welding points on nodes. Create Deviations : Create Input deviations on nodes. Create Activities : Create activities, assign them with positioning systems and welding, link them. Launch an Analysis and Visualize results : Compute a tolerance analysis. Visualize displacements for each activity.

36 90 min. Industrial context Exercise 2. Parts Assembly Tolerance analysis In this exercise you will learn how to compute a tolerance analysis from a product and a text file which contains tolerance analysis features and assembly process. We will also do modifications of the text file so as to add supports, joints and positioning systems.

37 Design Intent : Parts Assembly Tolerance analysis Load a product and TAA data from a text file. Study of the first Positioning activity. Statistical analysis. Add supports and joints. Replace a positioning system interactively and by the text file. Analyse and compare with the previous configuration.

38 Statistical analysis 3 Study of the first positioning activity 2 Load a product and TAA data from a text file 1 Add supports and joints by the text file 4 Analyse and compare 6 Replace a positioning system Interactively and by the text file 5 Design Process: Part Assembly Tolerance Analysis

39 5 min. Exercise Parts Assembly Tolerance Analysis : Load a product and TAA data We will see how to : Load a CATProduct file. Load TAA data from a text file.

40 Open a new process. Load the Traverse.CATProduct file. Load the text file. Let edit it and see its content : Resources (number: 1) Supports (number: 16) Joints (number: 16) Positioning systems (number: 9) Spot Welding (number: 10) Contacts (number: 2) Annotations (number: 2) Assembly process (number: 6) Load : Traverse.CATProduct Load : Data.txt Data are first applied on the geometry, then mesh is generated, and elements are created to link data to nodes. Incompatible mesh is taken into account. A …_out.txt file is always generated in the same folder after import. It shows all the TAA features loaded and finished where the import had stopped. Do It Yourself

41 10 min. Exercise Parts Assembly Tolerance Analysis : Understand the text file inputs We will see how the inputs of the text file are generated : Welding points Deviations

42 Once the text file loaded, let see in the tree and on the geometry. For example : Welding points : 10 spots generated. Deviations : 8 deviations generated. Spot Weld Contact Do It Yourself

43 15 min. Exercise Parts Assembly Tolerance Analysis : Study of the first Positioning activity We will only analyse the first activity of the process : Computing of the first positioning activity. Visualize Crossmember input deviations. Visualize Crossmenber deviations and positioning system.

44 Compute the first positioning activity. Visualize Crossmember displacements. Click on Visualization icon, and select the Crossmember part. Here are only crossmember deviations effects. Click on Visualization icon, and select the Positioning activity. Visualize Crossmember deviations and Positioning System. Double click two times on Dev.1 icon. Edit the corresponding Positioning System. Visualize symbols on geometry. Do It Yourself

45 30 min. Exercise Parts Assembly Tolerance Analysis : Statistical analysis We will do : Compute a statistical analysis of the last release activity. Visualize displacements and residual stresses for each activity. Check analysis results.

46 Process presentation Do It Yourself (1/3)

47 Launch a computation and select the last activity (Release). Visualize displacements for each activity. WeldingClosing Clamps Positioning Rail 303Positioning Rail 302 Positioning Cross member Release clamps Do It Yourself (2/3)

48 Check Analysis results. Choose a Determinist analysis. Select the Release activity. Check annotations and forces. Visualize Residual Stresses. Select the Release Activity. Mean Simu : Output deviation mean value computed from analysis, that we can compare with Mean Spec thanks to Mean Delta. Mean Spec : Target deviation mean value expected. Do It Yourself (3/3)

49 30 min. Exercise Parts Assembly Tolerance Analysis : Add supports and joints to prepare the tooling for the new component to weld We will see how can we add supports and mechanical joints with the text file, so as to prepare for the next process step and so decrease the displacements level.

50 Assembly studied Next process (not studied here) : Welding with another component Need to add two clamps (revolute type joints) to prepare the tooling for the new component to weld Mechanical joints to add here so as to rigidify rails and placed to avoid clash problems Do It Yourself (1/2)

51 Save as the Data text file, and rename it by Modif.txt. Add two supports : 1/ Change the number of supports from 16 to 18. 2/ Copy/Paste of 2 existent support blocks. 3/ Rename them by Sup_303 and Sup_302. 4/ Change coordinates by : (2738, -200, ) for 303 and (2738, 200, ) for 302. Add two mechanical joints : 1/ Change the number of joints from 16 to 18. 2/ Copy/Paste of 2 existent joints blocks. 3/ Rename them by Tight_303 and Tight_302. 4/ Choose a Revolute (1 rotation free) type. 5/ Change for between : Crossmember. 6/ Change coordinates (see Supports). Save the Modif text file. Do It Yourself (2/2)

52 30 min. Exercise Parts Assembly Tolerance Analysis : Replace a positioning system interactively We will create a new positioning system that will be used for the release activity. First, we will do it in an interactive way.

53 Load the product and the text file. See the 2 new mechanical joints. Create a new positioning system : 1/ Select the Positioning system icon. 2/ Call it Positioning Release. 3/ Select the two Revolute joints created before, and the two PIN2 and PIN2-2 cylindrical joints. 4/ Click OK. Assign the positioning system to the release activity : 1/ Select the unassign an item icon. 2/ Select the Release_Clamp activity. 3/ Select Positionning Crossmember for measurment, and Unassign. 4/ Select the item assignment icon. 5/ Select Positioning Release. 6/ Select Release_Clamp activity. Do It Yourself

54 30 min. Exercise Parts Assembly Tolerance Analysis : Replace a positioning system by the text file We will do the same thing but using the previous Modified text file, which is a faster way.

55 Open the Modif text file. Save as Modif2.txt. Create a new positioning system : 1/ Change the number of positioning systems from 9 to 10. 2/ Go to the end of the positioning systems part. Copy/Paste Positioning Crossmember for measurement. 3/ Rename it by positioning-Release. 4/ Change the number of joints by 4. 5/ Add Tight_303 and Tight_302 with a 0 value for Tightening. Assign the positioning system to the release activity : 1/ Go to the end of the text file, to the Release_Clamp block. 2/ Replace Positioning Crossmember for measurement by positioning-Release. Save the Modif2 text file. Load the product and the text file. PIN2 and PIN2-2 are cylindrical joints and had 1 as Tightening value, which corresponds to restrain Tx move. Put 0 here. Do It Yourself

56 30 min. Exercise Parts Assembly Tolerance Analysis : Analyse and compare We will compute a new tolerance analysis and compare displacements results with the previous configuration which had no tights in the release activity.

57 Compute the Release activity. Visualize displacements for the release activity (where the modified positioning system is used). Compare with the previous analysis. The two Revolute mechanical joints limit the torsion effects caused by the rails deviations. Do It Yourself

58 Fundamental Steps Load input data : Load a product. Load TAA data by a text file. Statistical analysis : Launch a tolerance analysis. Visualize displacements, forces and residual stresses. Check analysis results. Add supports and joints : Add supports and mechanical joints by the text file. Modify a positioning system interactively. Modify a positioning system by the text file.

min. Exercise 3. V4 Mesh Assembly Tolerance analysis In this exercise you will learn how to compute a tolerance analysis from a text file which contain components, tolerance analysis features and assembly process. We will also do a sensitivity analysis, and modify deviations and positioning systems.

60 Design Intent : V4 Mesh Assembly Tolerance analysis Using the text file. Compute and visualize results. Run a sensitivity analysis. Modify a deviation. Replace a positioning system. Resume

61 Compute and visualize results 2 Run a sensitivity analysis 3 Replace a positioning system 5 Import components and TAA data by a text file 1 Modify a deviation 4 Design Process: V4 mesh Assembly Tolerance Analysis

62 5 min. Exercise V4 Mesh Assembly Tolerance Analysis : Load data from the text file We will explain the text file contents : Components. Tolerance analysis features. Assembly process.

63 Open a new process. Load the text file. Let see its content : Assembly components (number: 4) Resources (number: 1) Supports (number: 24) Joints (number: 24) Positioning systems (number: 10) Spot Welding (number: 23) Contacts (number: 4) Annotations (number: 5) Assembly process (number: 7) Load : Input_5700. txt ` Here, models and text files must be in the same folder. Here, all the data are loaded by the text file, even the meshed assembly components. Do It Yourself

64 5 min. Exercise V4 Mesh Assembly Tolerance Analysis : Understand the text file inputs We will see how the inputs of the text file are generated : Welding points Deviations

65 Once the text file loaded, let see in the tree and on the geometry. For example : Welding points : 23 spots generated. Deviations : 5 sets of deviations. Do It Yourself

66 20 min. Exercise V4 Mesh Assembly Tolerance Analysis : Compute and visualize results Once the text file loaded, we just have to launch a computation. We will see how to Launch a tolerance analysis. Display displacements and residual stresses results.

67 Process presentation Part 3 Part 1 Part 2 Part 4 Parts 1&2 Parts 1&2 Part 4 Parts 1&2 Part 4 Part 3 Do It Yourself (1/3)

68 Launch a computation and select the last activity (Release). Visualize displacements for each activity. Release Welding Part3 Positioning with Part3 more Welding Part4 Positioning with Part4 more Welding Part1&2 Positioning Parts1&2 Do It Yourself (2/3)

69 Check Analysis results. Choose a Determinist analysis. Select Release activity. Check for Annotations and forces. Click on Mean Simu to order deviations. Visualize Residual Stresses. Select the Release Activity. Mean Spec : Target deviation mean value expected. Mean Simu : Output deviation mean value from analysis that we can compare with Mean Spec thanks to Mean Delta. Do It Yourself (3/3)

70 20 min. Exercise V4 Mesh Assembly Tolerance Analysis : Run a sensitivity analysis Now, we will run a sensitivity analysis to find the most influent input deviation.

71 Choose a Statistic Analysis for the Release activity. We have also access to S-D data. Click on Mean Simu until reorder output deviations and show the maximum value. It is the Dev.15 deviation, and its mean value is 7.3. The goal is to reduce this value. Select the Sensitivity Analysis option. Percentages of deviations participation can be visualized near the deviations points or nodes (with red arrows for strongest participations and blue arrows for the smallest ). Click on Dev.15. Look for the most influent input deviation. We see that this most influent deviation has a mean value of 0.41 and a Standard Deviation value of Close the Analysis Results window, and double click on the white arrow. The most influent input deviation is Dev.3 with a participation of 46%, from the Part3 component. Do It Yourself

72 25 min. Exercise V4 Mesh Assembly Tolerance Analysis : Modify a deviation Once we have find the most influent input deviation, we can reduce its mean value : Modify the most influent input deviation mean value. Re compute and visualize statistical results. Check the most important output deviation value.

73 Edit the Dev.3 deviation. Change the Mean value from 0.41 mm to 0.2 mm. Re compute the last release activity. Visualize statistic results and check the most important output deviation mean value. We notice that the most important output deviation has a mean value of 6.08 mm, whereas the previous value was 7.3 mm. Do It Yourself

74 25 min. Exercise V4 Mesh Assembly Tolerance Analysis : Replace a positioning system We have seen that the deviation value modification has not important consequences on the global result. So, we will try another solution by replacing a positioning system.

75 Change the Dev.3 mean value by the initial 0.41 value. We will delete the release activity positioning system. 1/ Select the unassign an item icon. 2/ Select the Release.7 activity. 3/ Select PositionSys9, and Unassign. Now, we can replace it by PositionSys.10 which contains a tight more (Joint.16). 1/ Select the item assignment icon. 2/ Select PositionSys.10. 3/ Select Release.7 activity. Re compute the release activity. Do It Yourself (1/2)

76 Compare the 2 positioning systems. Select Analysis data icon. 1/ Select the Release activity. 2/ Choose a Statistical analysis. 3/ Click on Mean Simu. We have now a mean value of 4.35 mm. We have added a tight to the Part3, where the displacements are important. Do It Yourself (2/2)

77 10 min. Exercise V4 Mesh Assembly Tolerance Analysis : Resume We will resume the different results thanks to displacements visualizations.

78 Compare displacements visualizations for each case. Dev.3 mean value : 0.41 Release : PositionSys9 Disp max : 9.08 mm. Dev.3 mean value : 0.20 Release : PositionSys9 Disp max : 7.56 mm. Dev.3 mean value : 0.41 Release : PositionSys10 Disp max : 5.54 mm. We have a diminution of 16 % with the modified deviation value from the initial configuration. With the replaced positioning system, we have a diminution of 39 % from the initial configuration. Do It Yourself

79 Fundamental Steps Load input data : Load a V4 mesh assembly and TAA data by a text file. Compute and visualize results : Launch a tolerance analysis. Visualize displacements and residual stresses. Visualize analysis results. Run a sensitivity analysis : Visualize sensitivity analysis results. Look for the more influent deviation. Modify a deviation and replace a positioning system : Change the parameters of a deviation statistical law. Unassign and assign items. Replace a positioning system. Compare the different solutions.

80 You can change thickness of parts under TAA. Compute only pre-processing. Double click on the part. In the contextual menu, select Representations and Manage Representations. Select the CATAnalysis file and Activate. Close. You have now access to the finite elements objects of the part in the tree. Hints and Tips