Dynamic behaviour of high‐strength sheet steel in dynamic tension: Experimental and numerical analyses

Abstract

This paper presents the behaviour of high-strength steel TRIP 700, frequently applied in automotive industries. This material is used to design some car components owing to high stress levels induced by phase transformation. Generally, a pre-plastic deformation is induced in the sheet steel at a low strain rate to transform austenite into martensite. The next step is to design for example a crash box, as described previously by Durrenberger et al. [1], in order to increase the level of energy absorption. The problem with testing this material is the specimen attachment during the tension test, notably at intermediate and high strain rates.A special problem appears when this material is used for crash applications, namely the plastic behaviour at intermediate strain rates 50 s−1∏ė∏3×102 s−1 and for the maximum stress level observed at ė max #103 s−1 must be defined correctly. In order to evaluate the behaviour of materials for this range of strain rates, servohydraulic machines are used. However, even if the actuator allows for velocities V 0 Á10 m/s, usually some problems appear during force measurement because the natural frequency of the load cell is too low. Even using a piezoelectric load cell, the material behaviour cannot be defined precisely. In order to obtain more precise information by force measurement, resistance strain gauges are generally used. One possibility is to cement these on to the specimen head. However, using this technique it is necessary to have a good knowledge of the parasite effects as discussed in this paper. Therefore, a coupled experiment-numerical simulation allows some effects due to the specimen design and resistance gauge position to be demonstrated.previously may be separated in terms of transition in JSA320

Effect of projectile nose shape on ballistic resistance of interstitial-free steel sheets

“…Zwick). A wide range of strain rates was covered at room temperature, Rusinek et al [13,14] showed that these dimensions of the tensile specimens ( Fig. 1) are optimum, which allows to achieve a proper level of stress coupled with sufficient ductility.…”

Modelling of thermo-viscoplastic behaviour of DH-36 and Weldox 460-E structural steels at wide ranges of strain rates and temperatures, comparison of constitutive relations for impact problems

“…This algorithm belongs to the class called return mapping, which are robust and widely used in practice (Simo and Ortiz, 1985;Simo and Taylor, 1986). The algo rithm was previously implemented into RK scheme in or der to simulate impact problems like dynamic tension test (Rusinek et al, 2005(Rusinek et al, , 2008a, dynamic ring expansion (Rusinek at al., 2007b) and perforation processes (Rusinek et al, 2008c). In the previous numerical work, (Rusinek et al, 2008c), several constitutive relations were evaluated, namely: PL, JC and RK.…”

“…Nowadays several publications can be found in the international literature dealing with high strain rate behaviour of different metallic materials directly related to engineering applications like automotive (Rusinek et al, 2008a;Larour et al, 2007;Mae et al, 2007;Smerd et al, 2005), civil (Kobayashi et al, 2008;Shanmugama et al, in press;Zaera et al, 2002), aeronautical (Fasanella and Jackson, 2001;Piekutowski, 1999) or naval (Nemat Nasser and Guo, 2003;Martineau et al, 2004) industries. Particularly, the behaviour of high strength sheet metals 1 when subjected to high velocity impact by rigid projectiles has raised a considerable interest as it is illustrated in the works (Borvik et al, 2002a,b;Gupta et al, 2006Gupta et al, , 2007Ar ias et al, 2008;Rusinek et al, 2008b).…”

Influence of Specimen Geometry on Split Hopkinson Tensile Bar Tests on Sheet Materials

“…In [7,8] the influence of the length to diameter ratio of the cylindrical specimens used in compression experiments is discussed and clear recommendations are given to minimise inertial and frictional effects. For tensile Hopkinson experiments, dogbone-shaped specimens are generally used; however, no agreement exists on the exact dimensions [9,10].…”