COPYRIGHT DASSAULT SYSTEMES FEM Surface CATIA Training Foils Version 5 Release 8 March 2002 EDU-CAT-E-FMS-FF-V5R8

COPYRIGHT DASSAULT SYSTEMES Course Presentation Objectives of the course In this course you will learn to quickly generate a finite element model for surface parts. Targeted audience CATIA V5 Users Prerequisites Generative Part & Assembly Structural Analysis in CATIAV5 Analysis Workbench 0.5 day

COPYRIGHT DASSAULT SYSTEMES Introduction to FEM Surfacep Accessing the Workbenchp User Interfacep.7 2. Mesh Specification and Creationp Global Parametersp Specificationsp Mesh Creationp Offset the Meshp Meshing Spot Weldsp Mesh Update and Modificationp Mesh Updatep Mesh Modificationp Mesh Quality Analysisp Direct Mesh Quality Visualizationp Quality Parameter Choicep Single Element Quality Analysisp Statistic Curvesp Open Bad Element Searcherp Edit an Analysis Reportp.52 5.Pre-processing Analysis Capabilitiesp Static Analysisp Frequency Analysisp Element Thicknessp.57 Frequently Asked Questions p.58 Table of Contents

COPYRIGHT DASSAULT SYSTEMES Introduction to FEM Surface In this lesson, you will learn about the FEM Surface Analysis Workbench by : Accessing the Workbench User Interface

COPYRIGHT DASSAULT SYSTEMES FEM Surface Surface Meshing CATIA FMS V5R6 Geometry : CATIA-GSD V5 (Generative Shape Design) Geometry: CATIA V4 Skin (*ski) Meshing specification associative with design changes Copy/Paste as Result Component Structural Linear Analysis CATIA GPS/EST V5R8 Assembly Structural Analysis (Linear) CATIA FEM/ELFINI V4 Other FEA Softwares (Durability, Crash, NVH,…)

COPYRIGHT DASSAULT SYSTEMES Start 3- Advanced Meshing Tools. A new CATAnalysis document is created. 2- Analysis & Simulation 1.1. Accessing the Workbench 4- Select an analyse type.

COPYRIGHT DASSAULT SYSTEMES Modification Tools toolbar Quality Analysis toolbar Meshing Methods toolbar Visualization Mode toolbar 1.2. User Interface - Toolbars Specification Tools toolbar

COPYRIGHT DASSAULT SYSTEMES Specification Tools Remove Holes, Gaps and Faces Add/Remove Constraints Nodes Distributions Set Global Meshing Pparameters Run Topology Initialization Mesh The Part Quality Analysis Intersection/Interferences Quality Analysis Visualization Visualization mode Standard Visualization Quality Visualization Modification Tools Remove Simplification Remove Mesh Manual Topological Modifications Nodes Distributions Remesh A Domain Edit Mesh Exit Meshing Methods Surface Mesher Export Mesh Mesh Offset Spot Welding Connections User Interface - Icons

COPYRIGHT DASSAULT SYSTEMES Analysis tree Associated Part Removed geometry for mesh topology Constrained geometry for mesh topology Pre-Processing Input User Interface - Tree

COPYRIGHT DASSAULT SYSTEMES General Process for a FEM Surface Analysis Mesh creation Mesh modification Analyse mesh quality Pre-processing Analysis Capabilities Ensure that the part has a material assigned Open FEM Surface Workbench Define global mesh parameters and specifications

COPYRIGHT DASSAULT SYSTEMES Mesh Specification and Creation In this lesson, you will learn how to define meshing parameters and specifications, and how to create the mesh. Global parameters Specifications Mesh creation Offset the Mesh Meshing Spot Welds

COPYRIGHT DASSAULT SYSTEMES Global Parameters - Access When creating a new surface mesh, the first step is to set values for Global Mesh Parameters. 1- Click on the surface Mesher Icon in the Meshing Toolbar Global Parameters panel is displayed 2- Select the Geometry to be meshed.

COPYRIGHT DASSAULT SYSTEMES Global Parameters - Basic Set Global Parameters values A surface Mesh Object is created in the Specification Tree It can be either triangle or quadrangle method. Mesh size value: global size assigned to the mesh. The maximum measure of how closely the element boundaries follow the geometry they are supposed to represent. Value according to which both the geometrical simplification and meshing will be offset. Sets the diameter for automatic hole deletion. Allows managing geometrical constraints that are too close to each others and generate elements that are too small (the system performs them).

COPYRIGHT DASSAULT SYSTEMES Global Parameters - Advanced Set Global Parameters values - Advanced Click More This edge will be constrained if the angle between the two faces is greater or equal to 10 degrees Same process for curves Angle computed between the two normals corresponding to neighbor faces. Angle computed between two tangents on a contour. Allows optimizing the position of the nodes in tight zones in order to improve the quality of the elements.

COPYRIGHT DASSAULT SYSTEMES An automatic geometric simplification is performed according to the Details Simplification - Minimum Size value Fillet Elimination Fillet replaced by a constrained topological edge for mesh Short Curves Suppression Before simplification After simplification Global Parameters - Details Simplification

COPYRIGHT DASSAULT SYSTEMES The Specification Tools toolbar is now available Click OK Free edges are displayed with green color Gaps are displayed with pink color Unspecified edges are displayed with white color Global Parameters - Geometric Elements Visualization

COPYRIGHT DASSAULT SYSTEMES Remove holes, gaps and faces - Add / remove constraints - Create node distributions - Global parameters - Initialize topology - Mesh 2.2. Specifications - Toolbar Presentation

COPYRIGHT DASSAULT SYSTEMES FMS Remove tools may simplify interactions between CAD and CAE modules : We can also pick up from GAS edges or nodes distributions of an assembly part so as to mesh the others parts. CAD topology made by designers is modified for meshing by analysis engineers through an FMS intermediate topology. Details can be ignored from the initial topology, like holes or gaps, and a final simplified topology can be meshed. This implies an important time saving and a simpler interaction between CAD and CAE. FMS Intermediate topology CADCAE Specifications - Principle

COPYRIGHT DASSAULT SYSTEMES Holes and gaps can be automatically or manually removed from the topology definition 1- Click on the Remove Holes icon in the Specification Tools toolbar 2-Click to see the value of the holes from the mini to the maxi. Removed holes turn from green to blue. Specifications - Remove Holes (1/2) Select to show the holes and gaps 3- Select the holes to ignore

COPYRIGHT DASSAULT SYSTEMES You can manually remove holes by selecting them with the mouse or by clicking on to reach the hole to be processed then by selecting it. Manually removed hole Specifications - Remove Holes (2/2)

COPYRIGHT DASSAULT SYSTEMES You can manually remove gaps and cracks by selecting them with the mouse. 1- Gap Suppression 2- Crack Suppression Specifications - Remove Gaps/Crack

COPYRIGHT DASSAULT SYSTEMES Specifications - Remove Faces You can manually remove faces by selecting them with the mouse. 2- Face Suppression 1- Click on Faces and select the Face to remove

COPYRIGHT DASSAULT SYSTEMES Specifications - Add/Remove constraints (1/2) 1- Click on the Add/Remove constraints icon in the Specification Tools toolbar 4- Selecting an unconstrained edge (displayed in blue) will set an Unspecified state on it (its color turns from blue to white) 2- Selecting an unspecified edge (displayed with white color) will set a constraint on it (its color turns from white to yellow) 3- Selecting an constrained edge (displayed in yellow) will set a No-constraint specification on it (its color turns from yellow to blue)

COPYRIGHT DASSAULT SYSTEMES Specifications - Add/Remove constraints (2/2) There are two types of constraints. a constraint applied to a vertex/point: as a result, a node will be created on this vertex. a constraint applied to a edge/curve: as a result, all the element edges will be aligned on this curve. Here you can see some examples.

COPYRIGHT DASSAULT SYSTEMES Specifications - Node Distributions 1- Click on the Create node distributions icon in the Specification Tools toolbar 3- Set the node distribution parameters 2- Select a geometry to create a node distribution (constrained or free edge) 4- Click OK

COPYRIGHT DASSAULT SYSTEMES Click on the Create node distributions icon in the Specification Tools toolbar 3- Set the Capture parameters Specifications - Capture 2- Select a meshed edge If you want to link the two meshes (between captured edge and edge part), select Coincidence and Condensation. Furthermore, a sufficient tolerance must be entered to find the two edges.

COPYRIGHT DASSAULT SYSTEMES You can modify Global Parameters during Specification Step. 1- Click on the Global Parameters icon in the Specification Tools toolbar 2- Validate or modify the Global Mesh Parameters Specifications - Access Global Parameters

COPYRIGHT DASSAULT SYSTEMES Specifications - Initialize Topology Allow a Pre-Visualization of the topology which will be used for mesh creation. 1- Click on the Initialize Topology icon in the Specification Tools toolbar The topology is created according to your specifications and displayed (free edges with green color and constrained edges in yellow) The mesh will be based on this topology. It allows to create geometry simplifications and mesh specifications without modifying the reference geometry

COPYRIGHT DASSAULT SYSTEMES Mesh Creation Create a mesh according to the global parameters specifications you have defined. 1- Click on the Mesh icon in the Specification Tools toolbar The mesh is created Ignored geometrical entities are not taken into account during meshing The Modification Tools toolbar is now available

COPYRIGHT DASSAULT SYSTEMES Offset the Mesh Offset the mesh you have created. 1- Click on the Offset The Mesh icon The Offset field in the Mesh Offset dialog box allows you defining which offset you want to apply relatively to a given normal. To modify the direction of the normal, click on it 2- Select the mesh 3- Give an offset 4- Click OK

COPYRIGHT DASSAULT SYSTEMES Meshing Spots Welds How to mesh spot welds that were previously defined in the Analysis Connections workbench. 1- Click the Spot Weld Mesher Icon The Spot Welding Meshing dialog box appears The Spot Welding Meshing dialog box is updated The spot welds appears meshed 2- Select the Spot Welding Analysis Connection in the features tree 3- Click OK

COPYRIGHT DASSAULT SYSTEMES Mesh Update and Modification In this lesson, you will learn how to update and modify a mesh on a single part. Mesh Update Mesh Modification

COPYRIGHT DASSAULT SYSTEMES Modify the geometry. 3- Update the geometry. Modified section 3.1. Mesh Update - Design Modification While in your CATAnalysis Document you can perform Design Modifications and then Update your previous mesh. 1- Double Clicking on the referenced part in the specification tree in order to enter in the part design Workbench.

COPYRIGHT DASSAULT SYSTEMES The previous mesh will be deleted, a warning message is displayed 2- Recompute the mesh. Mesh Update 1- Double Clicking on the mesh object in the specification tree in order to re- enter in the FEM Surface Workbench. Note that all your parameters and specifications have been kept.

COPYRIGHT DASSAULT SYSTEMES Remove Simplification Remove Mesh Manual Simplifications Imposed Nodes Re-Mesh a Domain Edit mesh Exit 3.2. Mesh Modification - Toolbar Presentation

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Manual Simplifications (1/3) With Manual Simplifications function, you can add or remove meshing constraints like Edges, Vertices and Swap, Split, Collapse or Merge conditions. 1- Click on Edit Mesh icon in the Specification Tools toolbar The Edit box is displayed For edges For vertices 2- With a right click, a contextual menu appears Choose this option if you want the computer to remesh automatically.

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Manual Simplifications (2/3) SwapSplitCollapseCut EdgeMerge EdgesUndo Simplifications Before After Click on both edges

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Manual Simplifications (3/3) Swap : Constrain or unconstrain an edge Split : Add/remove an imposed crossing line only between two vertices Collapse : Merge the two end-points of a constraint into one point Cut : Cut an edge in two parts Merge : Simplify and to merge two lines into one. Undo : Undo a mesh modification You can remove all the simplifications clicking on the Remove Simplifications icon

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Node distribution These modification function works exactly the same way as in the specification step. 1- Click on the Imposed Nodes icon in the Specification Tools toolbar 2- Select a geometry to create a node distribution 5- Recompute the mesh 3- Set the node distribution parameters 4- Choose a number of nodes for this geometry

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Remesh a Domain (1/4) 1- Click on the Re-Mesh a Domain icon in the Modification Tools toolbar 2- Select a domain (area closed by constrain edges) 3- Set mesh local parameters (method and size) 4- Click OK.

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Remesh a Domain (2/4) Mesh Size, Front and Mapped Quads Methods. Change Mesh Size from 5 to 2 mm Change method from Front Quads to Mapped Quads

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Remesh a Domain (3/4) Bead Quads Method. Front Quads Method Bead Quads Method

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Remesh a Domain (4/4) Projections. It permits reproduct the same meshing as on a surface to an other. There are a meshed surface and a projected area of it on an other surface After the re-mesh, both surfaces seem to have the same mesh.

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Edit Mesh (1/2) Edit Mesh allows the user to manually modify the mesh in order to improve its quality. 1- Click on the Edit Mesh icon in the Modification Tools toolbar Allows optimizing the shape of the element so that split elements meet desired Analysis criteria. When this option activated (the shape of the neighbor elements is altered in order to have the best possible quality of the elements) Allows combining two triangles into a quadrangle of good quality (when possible). Allows dragging a node on a surface Allows propagating smoothing modifications from one domain to a neighboring one Let's you launch again the Quality Analysis

COPYRIGHT DASSAULT SYSTEMES Mesh Modification - Edit Mesh (2/2) With the mouse you can move nodes (while following constraints) or split quadrangle elements into triangles. With a right click on a segment, you obtain a contextual menu To remove edges you previously created manually when splitting a quadrangle element To condense nodes on edges To insert a node on an edge

COPYRIGHT DASSAULT SYSTEMES Mesh Quality Analysis In this lesson, you will learn how to analyse elements quality and to create a quality analysis report. Direct Mesh Quality Visualization Quality Parameter Choice Single Element Quality Analysis Statistic Curves Open Bad Elements Searcher Edit an Analysis Report

COPYRIGHT DASSAULT SYSTEMES Quality visulization mode is activated clicking the quality visualization icon in the Visualization Mode toolbar Direct Mesh Quality Visualization Two visualization modes are available : standard and quality. 1- Standard visualization mode is activated clicking the standard visualization icon in the Visualization Mode toolbar.

COPYRIGHT DASSAULT SYSTEMES Quality Parameter Choice You can select the quality parameter you want to enforce in your analysis. 1- Click the Quality Analysis icon 2- Select the parameters in the Quality Analysis panel 3- Get informations about parameters definitions and thresholds

COPYRIGHT DASSAULT SYSTEMES Single Element Quality Analysis 1- Click the Quality Analysis icon 5- Select other elements to display their analysis 2- Select the Element Analysis icon in the Quality Analysis panel 3- Select a mesh element 4- Element Analysis is displayed

COPYRIGHT DASSAULT SYSTEMES Statistic Curves 1- Click the Quality Analysis icon Statistic curves parameters are defined in the Quality Analysis panel 2- Select the Statistic Curves icon in the Quality Analysis panel 3- Select a quality parameter 4- Move the mouse on the histogram intervals to get numerical values

COPYRIGHT DASSAULT SYSTEMES Open Bad Element Searcher 1- Click the Quality Analysis icon Get Single Analyze window Search other bad elements 2- Click the Open Bad Element Searcher icon

COPYRIGHT DASSAULT SYSTEMES Edit an Analysis Report 1- Click the Quality Analysis icon 2- Click the Quality Report icon 3- Data are available for : - Quality parameters - Elements types

COPYRIGHT DASSAULT SYSTEMES Pre-Processing Analysis Capabilities In this lesson, you will learn how to perform a pre-processing analysis before performing a static analysis in the context of the main exercise Static Analysis Frequency Analysis Element Thickness

COPYRIGHT DASSAULT SYSTEMES Static Analysis Once the surface mesh has been defined for the part, a static analysis of the surface mesh is performed exactly the same way as a static analysis on GPS. 2- Perform your surface mesh 4- Perform the static analysis like on GPS 1- From the surface meshing workbench, click on static analysis 3- Click Generative Structural Analysis in the Start menu

COPYRIGHT DASSAULT SYSTEMES Once the surface mesh has been defined for the part, a frequency analysis of the surface mesh is performed exactly the same way as a frequency analysis on GPS Frequency Analysis 2- Perform your surface mesh 4- Perform the frequency analysis like on GPS 1- From the surface meshing workbench, click on Frequency Analysis 3- Click Generative Structural Analysis in the Start menu

COPYRIGHT DASSAULT SYSTEMES Element Thickness Once the surface mesh has been defined for the part, the user has the possibility to enter an element thickness : in order for GPS to manage the geometrical model as the finite element support, you should have defined an External View in Generative Shape Design Workbench with Tools + External View. 1- Once the surface mesh has been defined, Click Generative Structural Analysis in the Start menu. Per defauIt, a thickness appears for all the part 2- Double-click on the thickness and change it

COPYRIGHT DASSAULT SYSTEMES To Sum Up … In this course, you have seen how to : Generate a finite element model for surface parts Modify a surface mesh Analyze the mesh quality Perform a static analysis Perform a frequency analysis

COPYRIGHT DASSAULT SYSTEMES Can we mesh only one single face from a solid Yes, you just have to simplify the geometry on selecting the surfaces you want to ignore in FMS. Do the mesh automatically update after a modification No, you must manually mesh with Mesh the part in FEM, or do another analysis selecting Mesh only in GPS. How can I use parabolic T6 elements Firstly, you must select the faces to mesh under GSD and choose External View. Then, go in GPS : the mesh is a linear triangle type per default, but you can select the OCTREE triangle mesh icon and choose parabolic element type, instead of linear (you can verify in computing mesh only, and in FMS select Quality Analysis, Quality Report and Mesh). Frequently-Asked Questions