鋭い圧子押込みにおける負荷除荷曲線を利用した薄膜材料の弾塑性特性評価

抄録

    An identification method with a sharp indentation for elastoplastic properties of film/substrate system is proposed. The method is based on extensive finite element computation on "soft film on hard substrate" cases indented with a sharp indenter. The method utilizes the substrate effect on load versus displacement relation in the indentation; this effect has often been regarded as undesirable. The computational results are expressed as response surfaces in a material parameter space. Based on the surfaces, and employing experimentally obtained load versus displacement relation, the elastoplastic properties of the film are identified. To determine the elastoplastic properties more accurately, it is important to use not only the loading curve but also the unloading curve. Numerical examples determined by this method for film/substrate system are given.