Crashworthiness Performance of Multi-Cornered Structures under Quasi-Static Compression and Dynamic Axial Loading Conditions

With increased consumer demand for fuel effcient vehicles as well as more stringent greenhouse gas regulations and/or Corporate Average Fuel Economy (CAFE) standards from governments around the globe, the automotive industry, including the OEM (Original Equipment Manufacturers) and suppliers, is working diligently to innovate in all areas of vehicle design. In addition to improving aerodynamics, enhancing internal combustion engines and transmission technologies, and developing alternative fuel vehicles, mass reduction has been identified as an important strategy in future vehicle development. In this article, the development, analysis, and experiment of multi-cornered structures are presented. To achieve mass reduction, two non-traditional multi-cornered structures, with twelve- and sixteen-cornered cross-sections, were developed separately by using computer simulations. In the original development of the non-traditional multi-cornered structures, a generic material was utilized and the crashworthiness characteristics of the two non-traditional multi-cornered structures were compared to those of the traditional structures with square, hexagonal, circular, and octagonal cross-sections. To further investigate the crashworthiness characteristics of the non-traditional multi-cornered structures for vehicle implementations, crash simulations were conducted to design a component test series. In the test series, one traditional and two non-traditional multi-cornered structures were included for comparison of crashworthiness characteristics. A 780-MPa third generation advanced high strength steel (AHSS), namely 780 XG3 (TM) steel that combines high strength and ductility, was chosen to produce the prototype parts of the three non-traditional multi-cornered structures. Two loading conditions, including quasi-static compression and dynamic axial loading conditions, were included in the test series. Prototype components made of 780 XG3 (TM) steel were fabricated using hydraulic press brake forming and MIG welding. Based on the results obtained from computer simulations and prototype tests, the two non-traditional multi-cornered structures exhibit enhanced crashworthiness characteristics compared to those of the traditional structures.