Using Shapes as Design Variables in HyperStudy

Using shapes as design variables in HyperStudy

Hello HyperStudy users,

HyperStudy can perform design exploration studies with size, shape, material etc. as design variables. In this blog, we will elaborate the process of adding shapes as design variables in HyperStudy using two different approaches.

Pre-requisite:

• Regardless of the approach to be used in HyperStudy for adding shapes as design variables, the pre-requisite is having a HyperMesh model with the required shapes. If support is required for creating the required shapes in the HyperMesh model, then, kindly contact the HyperMesh experts using hwsupport@altair.com.
• Once the required shapes are there in the HyperMesh model, one can follow one of the below mentioned methods to add the same as design variables in HyperStudy.

Method 1: Using HyperMesh Model type in HyperStudy

HyperStudy supports HyperMesh model as a model connection wherein the .hm file can be added as an input file to import the design variables such as shapes, thickness etc. However, from HyperStudy version 2021.1 & onwards, HyperMesh connector file (.hm2hst file) is also supported as an input file for importing the design variables such as shapes, thickness etc.

Detailed process of creating the HyperMesh connector file (.hm2hst file) from HyperMesh & adding the shapes as design variables in HyperStudy is explained below:

Steps to be followed in HyperMesh:

1. Open the .hm file in HyperMesh 2021.1 version onwards & click on 'Morph>Shapes'. Firstly, disable the 'Design Variable' selection (this is a mandatory step) enabled for the shapes by default (as shown in Figure 1) & save the HyperMesh file.

Figure 1 : Disabling the 'Design Variable' selection for the shapes under ‘Morph>Shapes’ in HyperMesh.

2. Then, click on 'File>Export>HyperStudy' (as shown in Figure 2) to create the HyperMesh connector file (.hm2hst file). In the dialog window, mention the 'Study Name' & select the folder for the file creation using 'Study Path'. Here, disable the option of ‘Launch HyperStudy’ & click on 'Export' (as shown in Figure 2).

Figure 2 : Export feature in HyperMesh & ‘HyperStudy Export’ dialog window for creating the HyperMesh connector file (.hm2hst).

3. Then, in the Model Parameters window, select the shapes & click on 'Add'. By doing so, the shapes will get added in the next section ‘HyperStudy Parameters’ (as shown in Figure 3). Then, click 'OK'. 

After this process, .hm2hst & .hm files will get created in the folder selected in the 'Study Path' option.

Figure 3 : Model Parameters window displaying the parameters (shapes) available in HyperMesh for exporting to HyperStudy.

Steps to be followed in HyperStudy:

1. In HyperStudy, add the HyperMesh model in the 'Define Models' step, select the .hm2hst file under 'Resource' & click on 'Import Variables' (as shown in Figure 4).

Figure 4 : Adding the HyperMesh model type & selecting .hm2hst file as a resource file in HyperStudy.

2. By doing so, the shapes will be imported as design variables from HyperMesh in HyperStudy.

Method 2: Using Parametrized File Model type in HyperStudy

This method is the traditional method of adding shapes in HyperStudy & Method 1 mentioned earlier is preferred over this method. However, when there is a requirement to include other parameters as design variables which are not available in HyperMesh by default such as loads, forces etc. along with shapes, then, this is the only method to be used.

Steps to be followed in HyperMesh:

1. For adding shapes using this approach, two files (.node.tpl & .shp) are required from HyperMesh.
2. To understand the process of creating these files from HyperMesh, kindly refer to the process detailed in the article (mentioned below).

HyperMesh: How to export shapes to use them in HyperStudy?

3. Using this process, the .node.tpl & .shp files can be created for various solvers such as OptiStruct, RADIOSS, ABAQUS, LS-DYNA etc.

Steps to be followed in HyperStudy:

1. In HyperStudy, add the Parametrized File model in the 'Define Models' step, select the .fem file under 'Resource'. By doing so, a dialog window (as shown in Figure 5) will appear. Here, click ‘Yes’ & by doing so, HyperStudy editor window will be opened.

Figure 5 : Adding the Parametrized File model & selecting .fem file as a resource file in HyperStudy.

2. Then, right click in the ‘Editor’ & select the option of ‘Select Nodes>GRID’ (as shown in Figure 6).

Note: the option of GRID, *NODE, /NODE, NODE / should be selected based on the solver file to be used. The GRID option is relevant only for OptiStruct.

Figure 6 : In the editor, use the ‘Select Nodes’ option to select the GRIDS from the .fem file

3. Once done, then, again right click in the ‘Editor’ & select the option of ‘Include Shape’ (as shown in Figure 7) & select the .node.tpl file from the folder automatically pointed out by HyperStudy.

Figure 7: In the editor, use the ‘Include Shape’ option to select the node.tpl file from the folder automatically pointed out by HyperStudy.

4. Then, edit the ‘Solver Input file’ to .fem (instead of default as .tpl) & add -optskip in the ‘Solver Input Arguments’. Then, click on 'Import Variables' (as shown in Figure 8).

Note:

• When other solvers are being used than OptiStruct, then add the relevant solver file name in the ‘Solver Input file’ section such as demo_0000.rad for RADIOSS, demo.inp for ABAQUS etc.
• When other solvers are being used than OptiStruct then adding -optskip in the ‘Solver Input Arguments’ is not required.

Figure 8 : Editing the ‘Solver Input file’ & ‘Solver Input Arguments’ for OptiStruct use-case.