OS-E: 0205 Car Bumper Impact

The bumper is one of the main parts which are used as protection for passengers from front and rear collision. Impact analysis (front bumper) using Nonlinear Transient Dynamic Solution in OptiStruct is demonstrated.



Figure 1. FE-Model

Model Description

A car bumper, modeled using first order shell elements and which is constrained in all DOF’s at the mounting locations. The stopper/impactor is rigid body first order shell elements + RBE2 with added mass for the inertia effect, which is then constrained in all DOF’s except X-translation. Sliding Contact is defined between the surfaces of the bumper (area in contact with the stopper during impact) and for the stopper surface. The initial velocity (applied on the stopper) of -694.44mm/s is applied.

The FE-Model properties are:
Shell and Rigid Elements
Bumper
First order Shell
Stopper
First order Shell with RBE2
The location where bumper is connected to other parts are constrained in all DOF.
The material properties are:
Bumper
Young's Modulus
2800 MPa
Poisson's Ratio
0.3
Initial Density
1.2e-9 ton/mm3
Stopper
Young's Modulus
2100000 MPa
Poisson's Ratio
0.3
Initial Density
7.82e-9 ton/mm3

Results

In Figure 2, the left top window shows the displacement contour and the graph in the bottom window shows displacement over time for node-1. Also, the right top window shows the von Mises Stress Contour in MPa at a simulation time of 0.1 seconds.


Figure 2.

Model Files

The model files used in this example include:

<install_directory>/hwsolvers/demos/optistruct/examples/Bumper_OS_Impact.fem