Equivalent Energy Absorption—A Methodology for Improved Automotive Crash Safety Design

Abstract

Safety norms across the world are becoming more and more stringent posing new challenges to achieve lightweight vehicle structures. Structures made of advanced/ultra-high strength steels (AHSS) play a vital role in meeting the vehicle safety targets, by absorbing large amounts of impact energy, as well as by withstanding higher impact loads that occur due to vehicle collisions. Safety simulations usually take longer solution times due to their complexity and nonlinear nature. Engineers often encounter with a problem of quick evaluation of safety performance using different grades of materials to optimize the weight and cost. A new methodology—equivalent energy absorption (EEA)—has been proposed to do a quick trade-off study on performance versus weight for various thicknesses and material combinations. A relationship is established between the gauge and grade of a component to derive an equivalent safety performance so that engineers can make quick decisions by conducting minimal number of simulations. A simple rectangular crush box was considered for study to assess the energy absorption (EA) with various material and thickness combinations. A design of experiments (DOEs) study was done using simulations with many numbers of material grades and gauges to construct a 3D response surface between gauge grade and EA parameters to understand the relationship between each of these parameters. A case study has been discussed in the paper about application of this methodology on a vehicle to evaluate its safety performance. It was found that more than 80% evaluation time is reduced using this methodology.

Formation of Oxides and Sulfides during the Welding Process of S700MC Steel by Using New Electrodes Wires

“…For welded structures of motor vehicle bodies to be characterized by high performance properties and ensure operational safety, joints must meet a few quality requirements. The authors of various scientific studies are looking for the possibility of proper welding of high-strength steel to obtain the following [12][13][14][15]:…”

“…For welded structures of motor vehicle bodies to be characterized by high performance properties and ensure operational safety, joints must meet a few quality requirements. The authors of various scientific studies are looking for the possibility of proper welding of high-strength steel to obtain the following [ 12 , 13 , 14 , 15 ]: Acceptable properties of the joint; Uniform hardness in the entire welded joint; High strength of the connection without welding defects. It should be emphasized that the martensitic structure of the latest high-strength steels used in the automotive industry is hard and brittle, which promotes the formation of cracks in the joint and significantly hinders the selection of welding process parameters.…”