OS-E: 0150 Large Displacement Analysis of Chassis
Demonstrates the use of 2D plate (shell) elements with large displacement analysis.

Model Files
Before you begin, copy the file(s) used in this example to
your working directory.
Model Description
This example is of a chassis modeled with shell elements and solves for large displacement
analysis with the load steps:
- Front torsional stiffness
- Rear torsional stiffness
- Vertical bending stiffness
Rail and Cross members modeled with shell elements, 7 are connected via rigid elements.
Displacements (translations and rotations), which are large enough to render small deformation theory invalid; therefore, the initial stiffness matrix is not suitable to represent the problem. This may result in either small or large (finite) strains. Large displacements are those that are greater than the characteristic dimension of the model (thickness of the beam plate or shell). This is always a nonlinear problem. A typical rule of thumb, if strains exceed 5%, always switch LGDISP=1.
Large deformations (geometric nonlinearity) the stiffness matrix is updated after each
loading increment. If you switch LGDISP=1, then the recent stiffness that
is taken to the next increment is already updated. Therefore, by having this on, the
deformed geometry or an updated stiffness matrix will be taken into the next step.
- FE Model
- Element Types
- CQUAD4
The linear material properties are:
- MAT1
- Young’s Modulus
- 2.1E5 MPa
- Poisson's Ratio
- 0.3
- Density
- 7.85E-9
- MATS1
- YIELD Point
- 350
Results
