Investigation of the mechanical response of a micro-textured surface using a higher order strain gradient plasticity theory

High strength steel sheets of thinner sections are being widely adopted in automotive industries for lightweighting purposes. However, dent resistance of steel sheets reduces with its thickness but increases with its surface yield strength. In this work, we explore the possibility of improving the strength of a sheet metal surface by a micro-texturing process with the aid of finite element simulations. Micro-texturing is expected to increase the strength of the surface because of the inherent size effect of the material and consequently improve the dent resistance. The mechanical responses of such a micro-texture, consisting of an array of rectangular micro-features, are studied for different loading conditions. A higher order strain gradient plasticity theory is employed to analyze the size effect of the micro-texture, under a small strain 2D finite element framework. The influence of the different geometrical features of the micro-texture and the length scale parameter of the material on the mechanical response, are investigated and the implications of these results on the dent resistance are discussed.

Automated summary

In this study, the possibility of improving the strength and dent resistance of high strength steel sheets by micro-texturing is explored using finite element simulations. The mechanical responses of the micro-texture are studied under different loading conditions, and the effects of geometrical features and material length scale parameter on the mechanical response are investigated.