Topology-Optimized Thermoplastic Beams for Automobile Crashworthiness 2011-26-0055

Thermoplastic materials, due to their inherent light weightiness and high ductility, are increasingly used in the design of front and rear beams of automobiles. These beams are found to be effective in reducing damages to engine and other costly components of an automobile during its low-speed collision with another automobile. While these beams are also advantageous in many other aspects that include performance and reduced assembly, cost is one of the limiting factors for the large-scale absorption of thermoplastic beams in automobiles. Therefore, in the current global economy, each automobile Original Equipment Manufacturer (OEM) is seeking an energy management solution that meets performance with minimum weight targets.

Topology optimization is capable of generating non-intuitive and optimum designs with minimum materials present. While this tool has been extensively used in the design of 2-D structures, some of the inherent features associated with it, limit its large-scale application for the design of lightweight 3 D structures. The problem is further worsened if manufacturing constraints are to be incorporated with topology optimization.

This paper presents a methodology to design injection-molded thermoplastic beams using topology optimization. The basic design is obtained using topology optimization and then it is fine-tuned to commercially fabricate it within the manufacturing limitations. Finally, in order to validate performance of the beam and to understand the usefulness of this methodology, simulations performed using Hypermesh and LS-dyna. Significant amount of reduction in weight and in the lead-time is observed with the application of this methodology for the design of beams for automobile crashworthiness.