Low speed collisions are common in areas with traffic congestion and parking occasions. These collisions burden economically the car owners and could have been avoided with a suitable design of car bumpers. Bumper beams are one of the most important structures in passenger cars, relative to the safety and the levels of protection of the vehicle chassis. Careful and appropriate design should be considered in order to achieve the best impact behavior.
There is no beaten track regarding the bumper beam design, neither its geometry nor the materials used. Consequently, there is a wide range of design and manufacturing philosophies used in modern cars and the research and development in this field is enormous and continuous.
The scope of this project was to design and simulate a light weight automotive bumper according to the full frontal low-speed impact test established by the IIHS (Insurance Institute for Highway Safety) & the RCAR (Research Council for Automobile Repairs). The design includes a prototypal and innovative bumper geometry and the simulation analysis was accomplished for materials that are quite common or will be the state of the art in the near future, like specific aluminum alloys, strengthened thermoplastics and composite materials. Comparisons in terms of weight and impact performance were made. The bumper’s geometry was invariable and the effect of interior additions, like horizontal/vertical composite absorbers or polystyrene foam, on the bumper’s deformation was studied, in order to assess the crashworthiness of each configuration.
The contribution of the advanced Applied Mechanics Laboratory to FEAC, by providing knowledge and technology transfer has been a key factor for the accomplishment of this project, which included:
- Parametric CAD modeling, drafting & parameters documentation
- APDL input files & macros
- Setup of the parametric explicit FE analysis
- Optimization of the structure to better fulfill the standards
- Procedure & results documentation
Physics Involved
- Structural analysis
- Composite materials
- Optimization
Tools Used
- Catia V5
- MSC Nastran/Patran
- Ansys Classic
- APDL Input Files & Macros
- ETA VPG
- LS-DYNA
- LS-Prepost