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.