マルチスケール有限要素解析による圧電セラミックスのミクロ結晶形態最適設計

抄録

In order to improve piezoelectric response of polycrystals in a macro scale, micro distribution of crystal orientations was optimized by using multiscale finite element method based on crystallographic homogenization theory. As a result, two characteristic optimum solutions were obtained for micro structure. One is a polycrystalline structure laminated with three specified grains for macro piezoelectric strain constant d₃₃₃, the other is a polycrystalline structure consisting of two regularly-neighboring grains with specified orientations for d₃₃₁. As the maximum micro strain occurs by electric and mechanical effects, the optimized micro structures exhibit the highest macro piezoelectricity that is beyond single crystal. Their micro structures are available for piezoelectric ceramics such as BaTiO₃ and Pb (Zr, Ti) O₃, that have the maximum piezoelectric strain constant under off-axis electric field.