•Automatically select mesh nodes that are the closest to the modeling points and create a separate set of nodes in an updated mesh file. •Add keywords in the updated mesh file that are needed to generate stiffness, mass and thermal load files. •Create the stiffness, mass and thermal load files by calling the FEA solver (e.g. Nastran.exe) The steps to create the updated input deck and stiffness matrix, using StiffGen are:•Use an FEA Pre-processor to create a mesh file that includes information for nodes, elements, type of mesh, thickness (for shell mesh), type of material, and material properties: Young's Modulus, Poisson's Ratio, Density, and Expansion Coefficient (for Thermal analysis). •Use StiffGen to automatically select the closest mesh node to each modeling point (already created in the 3DCS model). The initial mesh file will be used to select these nodes and add them to a node set, which is then listed towards the end of the updated mesh file. •The updated mesh file will then be run through FEA Post-processor (solver) to generate the reduced stiffness, mass, and load matrices. Notes:1. Only 3DOF stiffness matrix can be created for solid mesh (the rotations being constrained by the mesh itself). 2. If two or more modeling (part) points are coincident or very close to each other, they will be assigned the same mesh node (ASET). 3. All part points will be included in the creation of the reduced stiffness matrix, whether the points are active or not.
|
•Select the •Select one of the parts for which a mesh file and/or a stiffness matrix, a mass matrix or a thermal file will be generated. More parts can be selected to create the Stiffness Matrix and other referenced files. •Add an external mesh to be updated with the set of nodes closest to the modeling points for each part. •Select the units used to generate the mesh file in the [Mesh file units] fields. •Select the FE Solver using [Select FEA Tools] button. •Select file types to be generated and click [Generate FEA File for the Selected Part]. •Click [View Mesh File], [View Stiffness File], [View Mass File], or [View Thermal File] to see the specified file. •Click [Copy Files to Model Directory] button if you want to move the generated files to model directory folder. •Click the [Global Disp] button if you wish to output the global displacement. •Click [Close] to close the Stiffness Generating Dialog box. Use FEA Point Linking to verify if all the modeling points are linked to FEA nodes.
|
|---|
Add Part: Adds a part(s) from the tree or graph window.
Delete Part: Deletes a part(s) from the list.
Add/Replace Ext Mesh File: Adds the mesh file for the selected part. Pick the original mesh file created by a FEA pre-processor.
Mesh file units: The user must select the same units were used in the FEA software.
In StiffGen you have to select the units for Length, Force and Mass (when generating the mass matrix). These are the same units that were used to create the mesh file. Available units are: ofor Length: meter, millimeter, inch. ofor Force: Newton, milliNewton, pound-force. ofor Mass: kilogram, gram, pound, tonne, slinch ▪Slinch is an English unit of mass equal to 12 slugs (386.088 pounds-mass), that accelerates by 1 inch per second squared (1 in/s²) when a force of one pound-force (lbf) is exerted on it.
Data Reference: can be used to look at a sample value for Density and Young's Modulus. |
|---|
