Numerical and Experimental Analysis of Stress–Strain Characteristics in DP 600 and TRIP 400/700 Steel Sheets

Abstract

The body constitutes the largest proportion of the total vehicle weight. Recently, increasing efforts have been made towards reducing its weight and improving its crashworthiness. By reducing its weight, fuel consumption will be reduced, and this will also translate into lower CO2 emissions. In terms of safety, vehicle body components use high strength steel which can absorb a substantial amount of impact energy. The present study pays attention to DP 600 and TRIP 400/700 stress–strain characteristics at quasi-static strain rates. The stress–strain characteristics of absorption capacity, stiffness, and deformation resistance force were investigated experimentally by tensile tests, three-point bending tests, and numerical simulations. The results indicate the potential for increasing the absorption capacity, stiffness, and deformation resistance force of the vehicle body’s deformable steel components. The present study verified the possibility of replacing physical testing with numerical simulation. A reasonably satisfactory agreement between the experimentally determined stress–strain characteristics and the numerical simulation was achieved, which can reduce the development time of deformable vehicle body components, reduce costs and optimize the selection of materials. The results extend the state of knowledge on the deformation characteristics of high-strength materials and contribute to the optimization of body components in terms of passive safety and weight.

Numerical Simulation of Bending Steels Used in Automotive Industry With Emphasis on Springback

“…The main characteristic of TRIP steels is that they modify the microstructure during the plastic deformation process as part of the austenite transformation to martensite, with the following change in the material properties. One of the main issues of TRIP steels is strong elastic recovery, also known as springback, which occurs after forming [4,5]. The HSLA (high strength low alloy) steels are characterised by low carbon content, typically between 0.02 and 0.04 % and rather low amounts of alloying elements, up to 1,5 %.…”