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CAD & Parameters

Chapter Nine. CAD & Parameters. Chapter Overview. In this chapter, interoperability with CAD software as well as parameters will be discussed. The following will be covered: CAD Interoperability Multiple Design Studies Parameter Manager

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CAD & Parameters

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  1. Chapter Nine CAD & Parameters

  2. Chapter Overview • In this chapter, interoperability with CAD software as well as parameters will be discussed. • The following will be covered: • CAD Interoperability • Multiple Design Studies • Parameter Manager • The capabilities described in this section are generally applicable to all ANSYS licenses. However, some CAD functionality are specific to certain CAD software, so these will be designated accordingly. • Not all CAD software have the same features, so there are some differences in CAD-related functionality which is supported in Simulation March 29, 2005 Inventory #002215 9-2

  3. A. CAD Interoperability • As noted in Chapter 1, the following Geometry Interfaces are supported in Simulation: • The Geometry Interface license can be run in reader mode for all licenses. The Geometry Interface can be run in plug-in mode for the CAD software listed under “Associative” • Detailed CAD support listing in Simulation online help • IGES Geometry Interface reader is free March 29, 2005 Inventory #002215 9-3

  4. DesignModeler has a similar look and feel to Simulation DesignModeler can be used to create geometry in lieu of other CAD software DesignModeler can also read in parts and assemblies from the same CAD sources as Simulation. These models can be prepared and modified for analysis, then attached in Simulation … DesignModeler & CAD • DesignModeler is a Workbench module allowing users to create or prepare models for use in Simulation March 29, 2005 Inventory #002215 9-4

  5. … CAD Interoperability • There are various items which can be brought in from supported CAD systems when models are attached: • Geometry import • Spot weld import • Parameter import • Material property import • Coordinate system import • Named selection import • Motion loads import • CAD attribute processing • There are three ways of setting import preferences when attaching CAD geometry. • Three methods – one through the Workbench Projects page, another in Simulation Geometry branch, the third in Options… box – will be discussed next. March 29, 2005 Inventory #002215 9-5

  6. … Controlling CAD Settings • When importing models in Workbench Project page, the left side controls various CAD-related settings • These settings only affect the existing model March 29, 2005 Inventory #002215 9-6

  7. … Controlling CAD Settings • On the other hand, after a model is already imported into Simulation, CAD-related settings can be changed under the Geometry branch • These settings only affect the existing model March 29, 2005 Inventory #002215 9-7 Model shown is from a sample Inventor assembly.

  8. … Controlling CAD Settings • To change default behavior, go to “Tools menu > Common Settings: Geometry Import” to change default behavior • “Options” dialog box also accessible from Workbench Start page in lower-left corner. March 29, 2005 Inventory #002215 9-8

  9. … Geometry Import • For CAD-related settings, importing solid, surface, or line bodies is available • One cannot import a part with mixed solids and surfaces. • Assemblies with mixed solids and surfaces are OK. • In other situations, users may wish only toimport a particular entity type to ignore unnecessary or construction geometry present in the model • Hence, toggling import of solids, surfaces, and/or line bodies is possible March 29, 2005 Inventory #002215 9-9

  10. … Geometry Import (Solid Bodies) • Import of solid bodies is supported for all CAD systems • Contact regions will automatically be detected between parts in an assembly. • Note that the CAD mating relationship information is not used • Slider controls contact detection tolerance (in ANSYS Professional licenses and above, user can specify value in length units) March 29, 2005 Inventory #002215 9-10 Model shown is from a sample SolidWorks assembly.

  11. Individual Bodies (non-matching mesh) Single Part (matching mesh) … Geometry Import (Solid Bodies) • DesignModeler has concept of “multi-body parts” • A multi-body part is a group of solid bodies. Instead of using different mesh and contact regions between solid bodies, the bodies within a part will share nodes at common interfaces March 29, 2005 Inventory #002215 9-11

  12. … Geometry Import (2D Solid Bodies) • Before importing 2D geometry you must specify “Analysis Type” is “2D” in the Advanced Geometry options Once imported, the 2D details can be specified from the Part branch. Plane stress, plane strain or axisymmetric March 29, 2005 Inventory #002215 9-12

  13. … Geometry Import (Surface Bodies) • Simulation also supports import of surface bodies from most CAD systems • For ANSYS Professional licenses and above, surface body contact is available from the Contact branch • Spot weld definitions can also be used for surface assemblies March 29, 2005 Inventory #002215 9-13

  14. Individual Bodies (non-matching mesh) Part of Surface Bodies (matching mesh) … Geometry Import (Surface Bodies) • In DesignModeler, “joints” can be used to merge surface bodies together to a “part” • Instead of using spot welds or edge contact, “joints” in DesignModeler can ensure that surface bodies share nodes • Surfaces that share edges can also form a part to share nodes March 29, 2005 Inventory #002215 9-14

  15. … Geometry Import (Line Bodies) • Line bodies can be imported from DesignModeler only • Line bodies require cross-section definition and orientation, which only DesignModeler supplies • Line bodies are meshed with beam/link elements • Line bodies can be used in conjunction with surface bodies March 29, 2005 Inventory #002215 9-15

  16. … CAD Associativity • CAD associativity allows updating theCAD geometry in Simulation without needing to redefine material properties, loads, supports, and results • Slide 3 showed CAD systems which areassociative in Simulation • In some cases, for very large models,the processing time may take a while, so the user can turn off the CAD associativity feature to allow for faster attaching • Turning this feature off will make import faster but will not allow updating of the CAD geometry if changes to the CAD model are made • It is generally not recommended to turn this off unless the user does not need associativity Although the toggle is not available for DM and ProE, this does not mean that these systems do not support associativity. DM and ProE support associativity, just not the ability to toggle associativity off. March 29, 2005 Inventory #002215 9-16

  17. … Save Updated Model (Reader Mode) • Reader mode is when a model is attachedin Simulation without the CAD system being started up first • For Unigraphics, if the part is updated inreader mode, the updated file can be saved • This is used in conjunction with parametersto update the UG model with new dimensions March 29, 2005 Inventory #002215 9-17

  18. … Do Smart Update • “Smart Update” is a method by which the updating of assemblies is sped up if the assembly contains unmodified components. • Currently, only Inventor and Unigraphics support “Smart Update” feature March 29, 2005 Inventory #002215 9-18

  19. … Attach File via Temp File • For large models, it may be advisable toturn this feature on. • When attaching large models, a temporaryfile to facilitate import can be created/deletedby Simulation if this option is set • If set to “Yes”, a location for the temporarydirectory can be specified by the user March 29, 2005 Inventory #002215 9-19

  20. Not all CAD software support spot weld definitions in a manner usable by Simulation … Spot Weld Import • Spot welds can be used for surface assemblies • Although Simulation has some limited spot weld definition capabilities (at vertices only), spot welds can be defined more easily in DesignModeler and Unigraphics and then imported into Simulation. March 29, 2005 Inventory #002215 9-20

  21. … Parameter Import • Dimensions of CAD features can beimported into Simulation • By turning on this feature (default), anydimension with the user-defined prefix orsuffix (default is “DS”) will be imported into Simulation as a parameter • Only dimensions for features will be imported • Once imported, the parameters of variousdimensions will appear in the Details viewfor that particular part. • The use of parameters to change theCAD model or to set up parametric studieswill be covered in detail in the next section March 29, 2005 Inventory #002215 9-21

  22. Sample dialog boxes to change dimension name in CAD software … Parameter Import • Each CAD software has different ways to change the dimension name, so please refer to the CAD documentation • DesignModeler: checkmark the dimension, provide Parameter name • Pro/ENGINEER: select dimension, right-click “Properties” • Unigraphics: select dimension and “Edit” • SolidWorks: select dimension, right-click “Properties” • Inventor: select dimension, right-click “Dimension Properties” • Solid Edge: select dimension, right-click “Edit Formula,” change name • Mechanical Desktop: “Part > Design Variables” and define parameter name. Then change dimension to parameter via “Edit Dimensions” March 29, 2005 Inventory #002215 9-22

  23. … Material Property Import • If “Material Properties Transfer” is enabled,material properties, if defined, will be imported from supported CAD systems • The following properties will be imported: • Note that Simulation will not import UG properties in table form (such as temperature-dependent data) • If the material type is changed in CAD, this will be reflected in an update. However, if the values of the material property change in CAD, this will not update to prevent overwriting of user-defined values in Simulation. Not all CAD software support all material property definition which Simulation supports. Materials imported from CAD will appear in “Engineering Data” branch and will be assigned correctly to parts. March 29, 2005 Inventory #002215 9-23

  24. Sample dialog boxes to assign/define material properties in CAD software … Material Property Import • Each CAD system has different ways to define and assign materials, so please refer to the CAD documentation • DesignModeler: will import materials from ProE, UG, Inventor, but user cannot define material properties inside of DM directly • Pro/ENGINEER: “Edit > Setup: Material > Define/Assign” • Unigraphics: “Tools > Material Properties” • Inventor (to define materials): “Format > Materials”Inventor (to assign): right-click part “Properties: Physical tab” March 29, 2005 Inventory #002215 9-24

  25. … Coordinate System Import • Coordinate systems are used in Simulation to apply directional loads or results postprocessing • Coordinate systems allow users to define the orientation for direction-dependent loads or contour results • Simulation supports importing of local coordinate systems from some CAD systems • User-defined CS on part or assembly levelwill be imported • In DM and SW, names come through as-is.In ProE, name comes through as part name,followed by CS name in square brackets • Modified/added CS are updated with model March 29, 2005 Inventory #002215 9-25

  26. Sample dialog boxes to define coordinate systems in CAD software … Coordinate System Import • Each CAD system has different ways to define coordinate systems, so please refer to the CAD documentation • DesignModeler: create Plane, Details view: Export CS • Pro/ENGINEER: “Insert > Model Datum > Coordinate System” • SolidWorks: “Insert > Reference Geometry > Coordinate System” March 29, 2005 Inventory #002215 9-26

  27. … Named Selections Import • If “groups” are defined in the CAD package,these can be brought into Simulation asNamed Selections for supported systems.This makes it easier to assign mesh controls or apply loads to entities. • Named selections import can be enabled,as shown on the right • If the “group” in the CAD software has the specified prefix (default is “NS”), then it is imported in the Named Selection branch of Simulation March 29, 2005 Inventory #002215 9-27

  28. … Named Selections Import • However, note that this Named Selection processing feature is related to CAD API functionality. • Unless the CAD system allows direct manipulation of the entities, simply providing ‘names’ for geometric entities will not be imported into Simulation. • Interfacing with CAD API via VB or similar scripting languages may be required • Currently, only Pro/ENGINEER and Unigraphics (and DesignModeler) allow users to ‘rename’ geometric entities such as surfaces. • Pro/ENGINEER only allows one entity per named selection (limited usefulness) • Unigraphics allows for multiple names per named selection, so ‘true’ groups can be created March 29, 2005 Inventory #002215 9-28

  29. Sample dialog boxes to create “named selections” in CAD software … Named Selections Import • Each CAD system has different ways to rename geometric entities, so please refer to the CAD documentation • DesignModeler: “Tools > Named Selections” • Pro/ENGINEER: “Edit > Setup: Name > Other” • Unigraphics: select entities, right-click “Properties” March 29, 2005 Inventory #002215 9-29

  30. … CAD Attribute Import • The CAD Attribute Import capability canbe used to import attribute information from CAD software, including motion loads • For example, if a CAD system uses a supported kinematics program, the motionloads can be imported into Simulation for subsequent stress analyses • If this feature is turned on, the prefix can be specified. Only attributes with the given prefix (default is “SDFEA” or “DDM”) will be imported into Simulation. March 29, 2005 Inventory #002215 9-30

  31. B. Multiple Design Studies • In many situations, users may wish to perform comparisons of different load cases or even different types of analyses • Copying branches in the Outline Tree allow users to easily compare different Environments or even different Models One may wish to compare the results of two different load cases, as shown here March 29, 2005 Inventory #002215 9-31

  32. … Multiple Design Studies • To solve different cases, simply duplicate the parent branch • Duplicate the Environment branch when the user is: • Solving multiple load cases • Solving different types of analyses (static, modal, etc.) • Duplicate the Model branch when the user is: • Comparing different material properties • Comparing different geometry configurations • Comparing different contact conditions • Comparing different mesh densities • After duplicating the appropriate branch,simply make the necessary changes andthen resolve the model. • Usually, it is a good idea to rename thebranches in the Outline tree to distinguishbetween the duplicated branches March 29, 2005 Inventory #002215 9-32

  33. Select which branches you want to include in the HTML Report prior to generating it. All input, results, and figures will be included for each branch and labeled appropriately. … Multiple Design Studies • After duplicating the branch and resolving, the HTML Report will also contain all the cases solved March 29, 2005 Inventory #002215 9-33

  34. … Updating Geometry • For the aforementioned cases, changing the duplicate branch is straightforward • For example, to compare two different loading conditions, duplicate the Environment branch, then redefine or add/delete any loads or supports, as needed. • However, when dealing with multiple geometry configurations, additional steps are required • Make changes to geometry in the CAD system • Duplicate the Model branch • Select the Geometry branch, then choose “Geometry > Update: Use Geometry ParameterValues” from the Context toolbar This will work only for CAD systems whichare associative. After performing the abovesteps, the geometry for the selected branchwill be updated, and so will all materials,contact regions, and loads. March 29, 2005 Inventory #002215 9-34

  35. … Updating Geometry Example • For example, in the model below, geometry changes were made in the CAD software. • The Model branch was duplicated to “Model 2” • “Model 2” was selected and the new geometry was updated • All material assignment, mesh controls, (contact regions), and loads and supports were updated without manual intervention March 29, 2005 Inventory #002215 9-35

  36. … Sending Parameters and Updating • The method just described is an easy way to perform comparisons of different geometry configurations • Another way of updating the geometry is to do this from within Simulation • Recall from Section A “Parameter Import” of this chapter that dimensions with a user-defined prefix or suffix (default is “DS”) will import to Simulation as a parameter • If this is performed, each part will have its parameters (i.e., dimensions) shown in the Details view March 29, 2005 Inventory #002215 9-36

  37. … Sending Parameters and Updating • The CAD parameters may be changed in the Details view. Then, select “Update > Update: Use Simulation Parameter Values” from the Context toolbar, and Simulation will update the CAD geometry for that Model branch • Simulation actually sends the parameters to the CAD software, which regenerates the new model and sends it back to Simulation automatically • Note that the changes in dimensionsmust be such that a valid geometrycan be created in the CAD software.If not, the update will not succeed. March 29, 2005 Inventory #002215 9-37

  38. … Updating Geometry Notes • It is important to note the following when updating geometry from the CAD system • Only supported CAD systems (noted in the table below) have this feature. The CAD software must be installed locally on the same machine since Simulation uses the CAD API. • If the topology changes, some entity assignments (e.g., loading on a surface) may need to be redefined since the original item (such as a surface) is redefined. • If the topology changes, this results in the associativity being broken for that topology. This will be indicated with a “?” in the Outline Tree after an update. March 29, 2005 Inventory #002215 9-38

  39. … Updating Geometry Notes • Important points to keep in mind (continued): • All loads will have the same values as before, even if volumes, surfaces, or edges change in volume, area, or length: • The magnitude of all loads will remain constant. For example: • If force was applied on a surface and the surface area increased, the force magnitude remains the same but results in the force per unit area decreasing • If pressure was applied on a surface and the surface area increased, the pressure value remains the same, but this results in more force overall being applied on the surface • The orientation of loads will not change, either • For structural loads, if a direction is specified using existing geometry, the direction of the load will not change even though the geometry used for load orientation has changed March 29, 2005 Inventory #002215 9-39

  40. … Multiple Design Studies • Performing multiple design studies does not require that the Environment or Model branch be duplicated. • It is possible to insert a blank, new Environment branch from the Model branch • After inserting a new Environment branch, this branch will be blank. • Apply loads and request results, as desired • It is also possible to insert a completely different model in the same Simulation database • Go to the Workbench Project page. • Select the topmost project, the link to the “Active CAD Geometry” or to a “Geometry File.” • Use “Create a new Simulation” to bring in the model into the current Simulation database. • Set up analysis as usual March 29, 2005 Inventory #002215 9-40

  41. … Multiple Design Studies • To solve multiple branches at once, go to the parent branch and click on the Solve button • For example, if a user wants to only solve a single Environment, select that Environment branch from the Outline Tree and click on the Solve button • To solve all Environment or Model branches, select the parent branch and click on the Solve button. All child branches will then be solved sequentially. • To solve multiple Environment or Model branches, Ctrl-select the branches of interest, then click on the Solve button. • The active branch currently being solved will be indicated with a green lightning bolt. March 29, 2005 Inventory #002215 9-41

  42. C. Parameter Manager • Performing multiple design studies by duplicating the Model or Environment branch is an easy way to compare results • In the case of multiple Model branches, the Simulation database will become large because the mesh and results for each Model branch will be stored • For many cases, this may be a tedious, manual method • In some situations where many cases are being examined, the use of the Parameter Manager may be warranted • The Parameter Manager is useful to see the effect changes of input values have on certain output quantities. This is done in tabular form. • The Parameter Manager is not useful if the user needs to keep contour results, such as mode shapes of different geometries March 29, 2005 Inventory #002215 9-42

  43. Example of output parameters Example of input parameters … Understanding Parameters • In Simulation, input and outputparameters are used with the Parameter Manager • If a white input text entry in the Details view has a square next to it, it can be used as an input parameter • If a grey informative text entry in the Details view has a square next to it, it can be used as an output parameter • Simply select the square. A blue “P” will appear, indicating that this will be used with the Parameter Manager • Any items without a square cannot be used as a parameter. Moreover, any items not selected with a blue “P” will also not be used by the Parameter Manager March 29, 2005 Inventory #002215 9-43

  44. … Using the Parameter Manager • To activate the Parameter Manager: • Browse through the Outline tree and activate any input parameters which will be used (add blue “P”) • Browse through the Solution branch with results and activate any output parameters to be used (add blue “P”) • Use of Results Scoping (covered in Chapter 9) allows the user to query the local results. For example, by scoping results on selected surfaces, the max equivalent stress on the surfaces can be used as an output parameter • Select the Solution branch of the Environment of interest and select the Parameter Manager button • The Parameter Manager worksheet will appear (see next slide) March 29, 2005 Inventory #002215 9-44

  45. … Using the Parameter Manager • The Parameter Manager worksheet tab shows the defined input and output parameters under “Definitions” • The “Scenarios” is a table of cases which will be run March 29, 2005 Inventory #002215 9-45

  46. … Using the Parameter Manager • Each “Scenario” is a simulation which will be run • Under “Scenarios,” simply right-click to add rows • Each row represents a simulation • White input values can be changed to desired values • The grey output parameters reflect the result values • The last column indicates whether the solution has been performed. The types of status indicators are “Done,” “Ready,” and “Obsolete” • The row in bold is what is reflected in the Outline tree • Unlike the Multiple Studies method, the Parameter Manager does not store all results for all cases. The Outline tree will only reflect the last case (bold). • Check items which you want Parameter Manager to solve March 29, 2005 Inventory #002215 9-46

  47. … Using the Parameter Manager • After setting up the scenarios and clicking on the Solve button, the Parameter Manager will sequentially solve each check-marked case • If CAD parameters are present, ensure that the dimensions result in valid geometry • If any errors are encountered, the Parameter Manager will skip that scenario • After completed, the results for each scenario can be compared easily in the table. • The results can be exported to Excel (right-click on Parameter Manager branch in Outline tree to export) March 29, 2005 Inventory #002215 9-47

  48. DesignXplorer and DesignXplorer VT can be used to examine the effect input parameters have on output parameters. After running the analysis, through XY graphs, response surface plots, sensitivity pie charts, and spider plots, the user can get a better understanding of which parameters affect certain output and by what degree. This extends the use of parameters far beyond what is possible with the Parameter Manager. … DesignXplorer and Parameters • DesignXplorer and DesignXplorer VT are Workbench modules allowing users to obtain a full understanding of the relationship between input and output parameters March 29, 2005 Inventory #002215 9-48

  49. D. Workshop 9 • Workshop 9 – Parameter Manager • Goal: • Use the Parameter Manager to specify changes to the load magnitude and material properties of the model shown below and solve all scenarios at one time. March 29, 2005 Inventory #002215 9-49

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