三次元FEM固有方程式による三次元ピエゾ接合体の特異性オーダ解析

抄録

Joint structures of piezoelectric and no piezoelectric materials are often seen in intelligent structures. Generally, stress singularity fields exist at a vertex in the joint structures. It is necessary to examine their reliability for maintaining the performance of structures. Stress singularity may reduce the reliability of intelligent materials. Hence, the order of singularity at the vertex in three-dimensional piezoelectric joints is investigated. In the present study, 3D-FEM eigen equation is formulated based on the principle of virtual work. Piezoelectric effect is incorporated into 3D-FEM formulated for eigen analysis in elastic joints. Then, the influence of wedge angle at the vertex in three-dimensional joints on the order of singularity was investigated and the range of wedge angle disappearing the singularity was presented. It was found that the number of the order of singularity in piezoelectric joints is larger than that in elastic joints, and the order of singularity relating to the piezoelectric effect only exists. The variations of singularity order with dielectric and piezoelectric constants in joints of a block PZT and a half Al were analyzed. It was found that their influence on the order of singularity was reverse and piezoelectric property controlled the variation of the order of singularity in the case where the ratios of piezoelectric and dielectric constants vary simultaneously.