| 1. | Use the Element Set selector to define the elements that make up the free body and contain the nodes at which GPFORCE data will be extracted. |
The Set Browser tool can be used to create the necessary element sets.
| 2. | Use the Result System selector to define the coordinate system into which the grid point force and moment result vectors are transformed and output. |
If a results system is not specified, the HyperMesh "base" system is used by default.
The FBD Forces utility extracts grid point force and moment results from an results file in the output coordinate system in which the solver output these results. HyperMesh assumes that the output coordinate system assigned to each node in the HyperMesh database matches that used to run the analysis and generate the results file. Output coordinate systems are defined in HyperMesh by accessing the Systems panel. On the assign subpanel, select the required nodes and a coordinate system, and click Set Analysis. In OptiStruct and Nastran this operation sets the CD field on the GRID card(s). (See the OptiStruct online reference guide for more information regarding the GRID bulk data card.)
If the output coordinate systems for each node in the HyperMesh database do not match those used to run the analysis, the extracted values will be incorrect. This could occur when modifying a nodal output system within HyperMesh without rerunning the analysis and, or when loading a results file that does not match the currently loaded model. In addition, results coming from, or output to, cylindrical or spherical result coordinate systems should be inspected for validity near the origin and along principal axes.
| 3. | Use the Summation Node selector to define the node about which the GPFORCE data is summed for the selected element set. |
This is useful for verifying free body behavior through zero-sum values for all force and moment components about any node. It is also useful for calculating the result of applied or reaction forces about any node. If a node is not selected, the HyperMesh origin (0,0,0) is used by default.
| 4. | Activate the Show Model checkbox to automatically display the entire model in transparency mode while highlighting the currently selected element set, result system and summation node. This allows you to verify which element sets is currently selected. |
