Chapter 5 Accessing ANSYS Options Accessing ANSYS Options

Chapter 5 Accessing ANSYS Options

Accessing ANSYS Options Chapter Overview – Named Selections and ANSYS Components – Using Commands Objects – Loading a Simulation Environment Directly in ANSYS • The capabilities described in this section are generally applicable to ANSYS Professional licenses or above. ANSYS Workbench – Simulation • In this chapter, the following ways of interfacing with ANSYS will be covered: Training Manual February 4, 2005 Inventory #002177 5 -2

Accessing ANSYS Options A. Named Selections and ANSYS Training Manual • However, when the model is transferred to ANSYS, only node and element entities are sent – Solid model geometry is not referenced by the ANSYS solver – Because of this, it may be difficult to select or manipulate the model if only the finite element mesh is present • Named Selections provide a convenient way of selecting and manipulating the mesh – Named Selections are defined in Simulation – These are transferred as Components in ANSYS, where they can be selected or manipulated, as needed. ANSYS Workbench – Simulation • As will be seen subsequently, there are different ways to interface with ANSYS to access advanced functionality – To reference any “geometry” in ANSYS, the geometry must first be defined as a Named Component in Simulation February 4, 2005 Inventory #002177 5 -3

Accessing ANSYS Options … Transferring to ANSYS Training Manual – Vertex, edge, and surface named selections are transferred as nodal components with the same name – Named selections of solid, surface, and line bodies transfer as element components with the same name • Change the selection filter to “Body”. This allows selection of surface and line bodies, not just solid bodies! • The following conventions apply when Named Selections in Simulation are transferred as ANSYS Components: – Names beginning with a number have the prefix “C_” added – Spaces will be replaced by underscores – If multiple selection groups have the same name, only the last one is converted as an ANSYS component ANSYS Workbench – Simulation • Named Selections transferred as ANSYS Components: February 4, 2005 Inventory #002177 5 -4

Accessing ANSYS Options … Transferring to ANSYS Training Manual – Apply types of loads not supported in Simulation – Change element attributes – Define additional elements not supported in Simulation – Special postprocessing tasks – …etc. • Most ANSYS commands accept component names as an argument, facilitating component use in ANSYS • Named Selections are associative with the CAD geometry, so users do not have to worry if CAD model is updated ANSYS Workbench – Simulation • Once Named Selections are transferred to ANSYS, they can be referenced as Components to do the following: • Use of components is numbering-independent, so users do not have to worry if the mesh changes February 4, 2005 Inventory #002177 5 -5

Accessing ANSYS Options B. Overview of Command Objects Training Manual – The Command objects requires that the user has familiarity with APDL commands – Command objects can be inserted in the Part, Contact, Environment or Solution branches: • Part branch: commands are inserted following the material definition in ANSYS /prep 7 • Contact branch: commands are inserted following the contact definitions in ANSYS /prep 7 • Environment branch: commands inserted prior to the SOLVE command ANSYS Workbench – Simulation • Command Objects enable users to add APDL (ANSYS Parametric Design Language) commands, which expose advanced ANSYS functionality not otherwise available in Simulation • Solution branch: commands inserted after the /POST 1 command February 4, 2005 Inventory #002177 5 -6

Accessing ANSYS Options … Adding Command Objects Training Manual – A new branch with a Worksheet view will be shown where APDL commands can be inserted. ANSYS Workbench – Simulation • Adding command objects is done by right-clicking in the appropriate branch and using “Insert > Commands” February 4, 2005 Inventory #002177 5 -7

Accessing ANSYS Options … Parameterizing Command Objects Training Manual – Just as with other detail information throughout Workbench these arguments can be made parametric. In this example a command object placed in the Environment branch contains the NSUB command. The syntax of the command is: NSUB, Initial substeps, max substeps, min substeps Notice we have substituted ARG 1 in the command resulting in: Nsub, 10, arg 1, 2 ANSYS Workbench – Simulation • The details window for each command object can contain up to 9 parameter definitions (“ARG 1 to ARG 9”). This parameter can be used throughout Workbench including Design. Xplorer February 4, 2005 Inventory #002177 5 -8

Accessing ANSYS Options . . . Specifying Material Properties Training Manual • In the example below the “mp” command is used to modify the Young’s modulus for the material used for “Part 1”. – Notice the parameter “matid” is inserted into the command in place of the material’s reference number. ANSYS Workbench – Simulation • Command objects inserted in part branches allow quick material modification without having to know each part’s material number (ANSYS) February 4, 2005 Inventory #002177 5 -9

Accessing ANSYS Options . . . Specifying Contact Properties Training Manual • Can be used with symmetric or asymmetric contact pairs. • Insert ANSYS commands using parametric references. ANSYS Workbench – Simulation • Contact branch command objects can be used to modify ANSYS element type , real constant and material number data using parametric references. February 4, 2005 Inventory #002177 5 -10

Accessing ANSYS Options … Obtaining Output Parameters • Certain types of APDL parameters may be retrieved as Simulation parameters for use with design studies – A output “prefix” is specified (default is “my_”), so all APDL parameters with that prefix will be searched and parsed. – Output parameters can be used with Parameter Manager (discussed earlier in Chapter 10) or Design. Xplorer, enabling inclusion of APDL commands ANSYS Workbench – Simulation • Inserting a Command Object under the Solution branch allows for the use of postprocessing commands. Training Manual February 4, 2005 Inventory #002177 5 -11

Accessing ANSYS Options … Retrieving ANSYS Output Information Training Manual • Place the appropriate plot formating information (file type, size, etc. ) in the command object. • Issue the desired plot commands. • ANSYS plots are placed below the command object. • Plots are static images (see next page). ANSYS Workbench – Simulation • Command objects placed in the Solution branch can be used to retrieve plots from ANSYS February 4, 2005 Inventory #002177 5 -12

Accessing ANSYS Options … Retrieving ANSYS Output Information ANSYS Workbench – Simulation • ANSYS plots are retrieved below the command object. Training Manual February 4, 2005 Inventory #002177 5 -13

Accessing ANSYS Options … Linking with Text File Training Manual – The Command Object contents can be “refreshed” to reflect current text file contents – In Details view, linked filename will be shown ANSYS Workbench – Simulation • The Command Object’s contents can be exported or imported to/from a text file: February 4, 2005 Inventory #002177 5 -14

Accessing ANSYS Options … Command Objects Summary Training Manual – Commands branch provides pre- and post-processing access inside of ANSYS, including linking contents with external text files (e. g. , ANSYS input or macro files) – When used for post-processing, certain parameters with a given prefix may be retrieved back into Simulation. This is useful not only to view APDL parameter output but also for design studies, such as with Parameter Manager or Design. Xplorer – For users not as familiar with APDL commands, the Preprocessing and Postprocessing Commands branches, discussed next, provide an alternate means of including ANSYS functionality within Simulation. ANSYS Workbench – Simulation • Command Objects provide a convenient means of adding APDL commands to a Simulation model in order to access advanced ANSYS functionality not otherwise exposed February 4, 2005 Inventory #002177 5 -15

Accessing ANSYS Options C. Transferring Models to ANSYS Training Manual • In some cases, users may wish to transfer the Simulation model into ANSYS directly and run the model from there – All of these options will transfer the mesh only, not the solid model geometry, to ANSYS • There are three ways to transfer the mesh/loads to ANSYS: – Saving the Environment as a binary ANSYS database – Saving the Environment as an ASCII ANSYS input file ANSYS Workbench – Simulation • As seen in the previous section, the two types of Commands branches allow the user to add ANSYS APDL commands within the Simulation environment to access advanced functionality – Loading the Environment in an ANSYS session February 4, 2005 Inventory #002177 5 -16

Accessing ANSYS Options … Saving the ANSYS Database Training Manual – In the Details view of the Solution branch, change “Save ANSYS db” to “Yes” – Specify the ANSYS database filename in the “ANSYS db File Name” textbox, which will appear underneath – Solve the model, which will initiate solution and save the ANSYS database (*. db) – Things to keep in mind: • A solution must be initiated to create/save the. db file • The ANSYS. db file will be saved in the active units (Units menu) • This is also used in conjunction with saving ANSYS result files after a solution (see next slide) ANSYS Workbench – Simulation • During solution, the ANSYS binary database can be saved February 4, 2005 Inventory #002177 5 -17

Accessing ANSYS Options … Saving Other ANSYS Binary Files Training Manual – Use with the Postprocessing Commands Builder – Enable use to manually post-process within ANSYS later • In the “Tools menu > Options… > Simulation: Solution, ” user can save ANSYS files as well as specify where these files are stored. To save ANSYS files for each Simulation database, use the option “Use Project Directory. ” ANSYS Workbench – Simulation • ANSYS files written during solution may also be saved: February 4, 2005 Inventory #002177 5 -18

Accessing ANSYS Options … Writing an ANSYS Input File Training Manual – Select a Solution branch – Select “Tools > Write ANSYS Input File” and enter the name and location of the input file – Things to keep in mind: • As with saving the binary ANSYS database, only the currently selected Environment will be written. Write multiple input files for each Environment branch to be saved. • Unlike saving the binary ANSYS database, this option does not require a Simulation solution. If loads/supports and requested results are incomplete, Simulation will not know what type of analysis to specify, so the model may be transferred as MESH 200 generic ‘mesh-only’ elements. Otherwise, see previous chapters as to how the model will be translated to ANSYS Workbench – Simulation • An ANSYS input file may be generated, independent of the Simulation solution • There will be an /EOF command prior to SOLVE – To make the input file generate the mesh and solve, simply February 4, 2005 remove the /EOF line in any text editor Inventory #002177 5 -19

Accessing ANSYS Options … Loading Environment in ANSYS Training Manual – In the Workbench Project page, select a “Model” – On the right-side menu, one can list Environments contained in that Model branch – Select the Environment of interest to load into ANSYS Workbench – Simulation • It is possible to load an Environment directly into ANSYS: February 4, 2005 Inventory #002177 5 -20

Accessing ANSYS Options … Loading Environment in ANSYS Training Manual – The analysis may be continued from within ANSYS • Note that any actions performed in ANSYS will be captured in an ANSYS log file, but these will not be stored in Simulation • When leaving ANSYS, the user will be prompted to save files ANSYS Workbench – Simulation – After selecting the Environment, the ANSYS Output Window will appear, and the Workbench GUI will change to ANSYS February 4, 2005 Inventory #002177 5 -21

Accessing ANSYS Options … Loading Environment in ANSYS Training Manual – The subdirectory name will be called “filename_num” where “filename” is the name of the. dsdb file and “num” is the numerical Environment number • For example, for the third environment branch of a Project. dsdb file, the subdirectory will be named “Project_3” – All ANSYS-generated files, including the input file, error file, log file, and database, will be contained in the subdirectory • filename_AWE. inp: text input file generated from Simulation and automatically read into ANSYS • filename. db (optional): binary ANSYS database of mesh and loads • filename. err: text file containing all error or warning messages ANSYS Workbench – Simulation • All pertinent files from the ANSYS session will be stored in a new subdirectory in the Solver Working Directory • filename. log: text file containing ANSYS command history • filename. page: temporary binary file (leave untouched) February 4, 2005 Inventory #002177 5 -22

Workshop 5 Accessing ANSYS Options Hyperelastic with Contact Nonlinear Analysis of a Keyboard

Accessing ANSYS Options D. Workshop 5 – Hyperelastic with Contact Training Manual – General use of Commands object in the Geometry, Environment, and Solution branches – Use of Named Selections will facilitate manipulating data in ANSYS – Output parameters and plots will be retrieved from the solution ANSYS Workbench – Simulation This exercise will cover accessing ANSYS options through the Commands object. A 2 D analysis of a portion of a hyperelastic keyboard will be performed, as shown below. – Items shown with round bullet points are tasks to be performed. February 4, 2005 Inventory #002177 5 -24

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact • Under the “Geometry” branch in the Details view: – Turn off import of solid and line bodies and only select import of surface bodies – Change the “Analysis Type” to “ 2 -D” • From the Context toolbar, choose “Geometry > From File…” and select the Parasolid file “keyboard. x_t” ANSYS Workbench – Simulation • Launch Workbench and open a new Simulation session Training Manual – The model will be attached to Simulation, as shown next February 4, 2005 Inventory #002177 5 -25

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact • Right-click on “Part 1” and select “Rename” to rename it to “ground” • Likewise, right-click on “Part 2” and rename it to “keyboard” • Right-click on “keyboard” and select “Insert > Commands” from the popup menu – In the contents of the Commands object, type the following: ANSYS Workbench – Simulation • Select the menu item “Units > Metric (mm, kg, N, °C, s, m. V, m. A)” Training Manual mpdele, all, MATID tb, hyper, MATID, 1, , neo tbdata, 1, 80. 194 February 4, 2005 Inventory #002177 5 -26

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – The “matid” parameter is used to reference the material ID for that given part, so the element type or material can easily be changed using ANSYS commands – The active Simulation units are used during analysis, so it is important that all materials defined in the Commands object have the same units as the active Simulation Units. mpdele, all, MATID tb, hyper, MATID, 1, , neo tbdata, 1, 80. 194 Contact regions can also be changed in a similar manner under the “Contact” branch. The ANSYS APDL parameters “CID” and “TID” refer to the contact and target real constant numbers. ANSYS Workbench – Simulation The commands that were added in the previous slide delete the existing material properties for the “keyboard” part and replace it with a neo. Hookean hyperelastic model. Training Manual February 4, 2005 Inventory #002177 5 -27

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – In the Details view, ensure that “Plane Stress” is the “Behavior” – Enter “ 10” mm for the “Thickness” In this example, the keyboard is assumed to have a plane stress state with a thickness of 10 mm. ANSYS Workbench – Simulation • Using the Control Key, select both “ground” and “keyboard” from the Geometry branch Training Manual February 4, 2005 Inventory #002177 5 -28

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – The contact pair will be renamed to “ground To keyboard, ” as shown on the right In this case, the automatic contact detection selected the top of the “ground” as the contact surface (red). We need to flip the contact pair such that the top of the “ground” is the target, as it is the stiffer material. ANSYS Workbench – Simulation • Right-click on “Contact Region” under the Contact branch and select “Rename Based on Geometry” Training Manual • Right click on “ground To keyboard” and select “Flip Contact/Target” February 4, 2005 Inventory #002177 5 -29

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – The bottom of the keyboard will be highlighted. With the “Edge” selection active and the Control key pressed, select the other two lines as shown on the right, as these will be expected to touch the ground – Click on “Apply” to complete the selection – Change “Type” to “Frictionless” – Change “Behavior” to “Asymmetric” – Change “Formulation” to “Augmented Lagrange” ANSYS Workbench – Simulation • In the Details view, select “Contact”. Training Manual – Toggle “Pinball Region” to “Radius” and enter “ 10” mm for the radius. February 4, 2005 Inventory #002177 5 -30

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – The “Element Size” should be set to “ 1” mm – Change “Curve/Proximity” to “ 100” – The “Shape Checking” can be switched to “Aggressive” • Change the selection filter to “Face” and select the “ground” part. From the Context toolbar, select “Mesh Control > Mapped Face Meshing”, as shown on the right ANSYS Workbench – Simulation • Select the Mesh branch and, in the Details view, toggle the “Global Control” to “Advanced” Training Manual – The “Element Shape” can be set to “Quadrilaterals” February 4, 2005 Inventory #002177 5 -31

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – From the Context toolbar, select “Mesh Control > Sizing” – In the Details view, change “Type” to “Number of Divisions”, with the number of divisions being 1 In this example, the ground is not of interest and is much stiffer than the keyboard, so it will be meshed with just one element. ANSYS Workbench – Simulation • Change the selection filter back to “Edge” and select the four lines of the “ground” part, as shown on the right Training Manual • Right click on the Mesh branch and select “Preview Mesh” February 4, 2005 Inventory #002177 5 -32

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – When asked for a name, enter “PUSH_TOP” A new Named Selection branch and PUSH_TOP object will be created in the Tree. The Named Selection can be referenced as a nodal component in ANSYS Command objects in order to manipulate the model. In this case, a special loading will be applied to the nodes in “PUSH_TOP” ANSYS Workbench – Simulation • Select the topmost line of the “keyboard” part and select the “Create Selection Group” icon Training Manual February 4, 2005 Inventory #002177 5 -33

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – From the Context toolbar, select “Structural > Frictionless Support” • Do the same for the rightmost line of the “keyboard” part and add a Frictionless Support there as well. ANSYS Workbench – Simulation • Highlight the Environment branch, then select the leftmost line of the “keyboard” part Training Manual February 4, 2005 Inventory #002177 5 -34

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – Add “Structural > Fixed Support” from the Context toolbar • Right-click on the Environment branch and select “Insert > Commands” – In the Commands object, select “Import” from the Context toolbar – Select “keyboard 2. mac” as the file – The contents of “keyboard 2. mac” will be inserted into the Commands object ANSYS Workbench – Simulation • Select the bottommost line of the “ground” part Training Manual February 4, 2005 Inventory #002177 5 -35

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact Training Manual – All results are saved for each substep – The nodal component (Named Selection) called “PUSH_NODE” is selected, and a coupled set for the ydirection is created for all of the nodes – A displacement of – 54 mm is applied in the y-direction on the master node of the coupled set. – An element plot is generated, so the user can see the mesh and boundary conditions in Workbench Simulation /show, png time, 54 outres, erase outres, all cmsel, s, PUSH_TOP PUSH_NODE=ndnext(0) cp, next, uy, all d, PUSH_NODE, uy, -54 allsel, all ANSYS Workbench – Simulation It may be worth pausing for a moment to examine the commands inserted from “keyboard 2. mac” /pbc, all, 1 eplot /show, close February 4, 2005 Inventory #002177 5 -36

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – “Solver Type” to “Direct” • This model has hyperelastic and steel materials, so the matrix may be illconditioned. The sparse direct solver will suffice for such a small problem. – “Weak Springs” to “Off” – “Large Deflection” to “On” • Although the text box may change to yellow, this is because no results have been requested yet. – “Auto Time Stepping” to “On” ANSYS Workbench – Simulation • Select the Solution branch. In the Details view, change the following: Training Manual – “Initial Substeps” and “Minimum Substeps” of “ 10” and “Maximum Substeps” of “ 1000” February 4, 2005 Inventory #002177 5 -37

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – “Stress > Equivalent (von-Mises)” – “Strain > Equivalent (von-Mises)” – “Deformation > Total” – “Tools > Solution Information” – “Tools > Contact Tool” • Change the Contact Tool detail to “Worksheet”, change “Contact Side” to “Contact” > “Apply”. • Then RMB > Insert: ANSYS Workbench – Simulation • From the Context toolbar, select the following: Training Manual – “Contact > Pressure” – “Contact > Penetration” February 4, 2005 Inventory #002177 5 -38

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact • Right-click on the Solution branch and “Insert > Commands” – From the Context toolbar, select “Import” and read in the “keyboard 3. mac” file – The contents will be displayed in the worksheet. Notice the inclusion of the output parameter “MY_REACTION” in the Details view. ANSYS Workbench – Simulation There are some type of results that cannot be viewed directly from Simulation. These include loadhistory response (POST 26) as well as element table items Training Manual February 4, 2005 Inventory #002177 5 -39

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact Training Manual – The Time-History Postprocessor is used to plot force vs. displacement at the top of the keyboard – The General Postprocessor is then used to get the reaction force due to pushing the keyboard down. This is reported as “MY_REACTION, ” which is also recognized by Simulation as an output parameter that can be used with the Parameter Manager or Design. Xplorer – The resulting thicknesses are also plotted. /post 26 rforce, 2, PUSH_NODE, f, y, FORCE /axlab, x, Displacement /axlab, y, Force plvar, 2 finish /post 1 set, last *get, MY_REACTION, node, PUSH_NODE, rf, fy /title, Equivalent Stresses plesol, s, eqv, 2 ANSYS Workbench – Simulation • The “keyboard 3. mac” contains postprocessing ANSYS commands /show, png /title, Out-of-plane Thicknesses plesol, nmisc, 1 /show, close February 4, 2005 Inventory #002177 5 -40

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact • Select the “Solution Information” branch to review the contents of the Output window. – The “Force Convergence” graph can also be reviewed during solution to monitor the progress of the analysis – At the end of the solution, a warning message may appear. The user does not have to worry about this, as the frictionless supports used in this example are fine for this largedeflection solution. ANSYS Workbench – Simulation • Click on the “Solve” icon to initiate the solution. Training Manual February 4, 2005 Inventory #002177 5 -41

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – Change the scaling in the Context toolbar to “ 1. 0 (True Scale)” – The undeformed model may also be superimposed to get a better sense of how much the keyboard deformed. – Note that the equivalent elastic strains are very large (~66%), as this is a hyperelastic model. Review other results, such as stresses, deformation, and contact results. Contact pressure distribution is shown on the right. ANSYS Workbench – Simulation • Select “Equivalent Elastic Strain” and review the strains. Training Manual February 4, 2005 Inventory #002177 5 -42

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact – If no objects are shown under the Commands branch, click on the Workbench Project tab on the very top, then return back to Simulation tab to refresh the window • Select “Post Output 2” – this is a plot of force vs. deflection in the y-direction. – Note that the force is relatively small at first. Then, the slope changes when the front of the keyboard initiates contact. Another change in slope occurs when the middle contacts the ground. ANSYS Workbench – Simulation Note that under the Commands object in the Solution branch, there are four “Post Output” objects Training Manual February 4, 2005 Inventory #002177 5 -43

Accessing ANSYS Options …Workshop 5 – Hyperelastic with Contact “Post Output 4” shows the final thicknesses – Recall that the initial thickness was 10 mm (Step 3) – Because of the incompressibility of the hyperelastic material, some areas (yellow) became thinner while other areas (red) became thicker. • “Post Output 3” shows equivalent stresses – Note that the max stress in ANSYS is 141 MPa while max stress is 140 MPa in Simulation. This slight difference is due to the fact that ANSYS has different options for output, including averaged or unaveraged stresses, so the user has more control over output results with the Commands object. ANSYS Workbench – Simulation • Training Manual February 4, 2005 Inventory #002177 5 -44