OS-E: 0190 Large Displacement Subcase as Preload to Linear Subcases

Preloaded or Prestressed Linear Analysis is any type of structural linear analysis performed on a structure under prior loading.

Large displacement nonlinear subcase can be selected as preload to linear subcase, which is specified through STATSUB(PRELOAD). This would take the deformed shape of the nonlinear large displacement subcase into account for the subsequent linear subcase.

Model Description

Model A is a rectangular plate of dimension 1000*200 mm consisting of CQUAD4 elements with average element size of 25. A pressure load of 0.02 MPa along negative Z-direction is considered for subcase 1. The subcase 1 is considered as the preload along with the pressure load of 0.02 MPa in negative Z-direction for the subsequent linear static subcase.

Model B is a circular plate of radius 300mm and 4mm thickness consisting of CHEXA elements. A pressure load of 1.0 MPa along negative Z-direction is considered for subcase 1 to perform nonlinear static analysis. The subcase 1 is considered as the preload in the subsequent modal frequency response analysis subcase.

The material properties are:
Young's Modulus
210 x 103 MPa
Poisson's Ratio
0.3
Initial Density
7.9 x 10-6 ton/mm3

Results

Nonlinear large displacement subcase with linear static subcase.


Figure 1. Nonlinear Large Displacement Subcase Solution for Model A


Figure 2. Linear Subcase Solution with Nonlinear Large Displacement Subcase as Preload for Model A

The maximum displacement of 293.5 is observed for the node 23 for the nonlinear large displacement subcase and a maximum displacement of 187.7 mm for the subsequent linear subcase.

Nonlinear large displacement subcase with modal frequency response subcase.


Figure 3. Nonlinear Large Displacement Subcase Solution for Model B
The maximum displacement of 98.482 mm is observed at the node 26 for the nonlinear large displacement subcase and maximum displacement of 0.01236 mm is observed at the node 20 for the modal frequency response subcase.


Figure 4. Modal Frequency Response Subcase Solution with Nonlinear Large Displacement Subcase as Preload for Model B

Model Files

The model files used in this example include:

<install_directory>/hwsolvers/demos/optistruct/examples
  • /53_Plate_LGDISP_Support_wPRELOAD.fem
  • /53_Disk_LGDISP_Support_wPRELOAD.fem