题目：Fracture and Crack Mechanics of Piezoelectric Material Systems under Electric Fields
报告人：Professor Y. Shindo
Dept. Materials Processing, School of Engineering, Tohoku University, Japan
In most of the applications as sensors and actuators in the field of smart structures and devices, piezoelectric ceramics are subjected to both high mechanical stresses and intense electric fields, hence, it is important for reliability and durability to investigate the fracture and crack behavior of piezoelectric material systems. Here, the results on the electrical loading dependence of cracking of piezoelectric ceramics are reported. The indentation fracture, single-edge precracked beam (SEPB), and double torsion tests are performed. Finite element analyses are then employed to study the crack behavior in piezoelectric material systems, and the effects of crack face boundary conditions (permeable, impermeable, open and discharging crack models) and localized polarization switching on the fracture mechanics parameters (e.g. energy release rate) are discussed. The modified small punch tests and corresponding finite element analysis are also performed and a non-linear relation between fracture initiation load and electric field is obtained. Furthermore, the results on the static, cyclic and dynamic fatigue behavior in SEPB piezoelectric specimens under electromechanical loading are presented.
About the speaker
Dr. Shindo received his Doctor of Engineering from Tohoku University in 1977. He is currently a professor in the Department of Materials Processing in the Graduate School of Engineering at Tohoku University. Dr. Shindo also served on the Board of Editors of International Journal of Solids and Structures, the Editor-in-Chief of Journal of Mechanics of Materials and Structures, the Advisory Board of Acta Mechanica, the International Editorial Board of AES Technical Reviews International Journal (Part A: International Journal of Nano and Advanced Engineering Materials (IJNAEM), Part B: International Journal of Advances in Mechanics and Applications of Industrial Materials (IJAMAIM)), the Editorial Advisory Board of The Open Mechanics Journal, The Open Civil Engineering Journal, the Editorial Board of Advances in Theoretical and Applied Mechanics and the Editor-in-Chief of The Open Mechanical Engineering Journal. His primary research interests are in the areas of mesomechanics of material systems and structures, electromagnetic fracture and damage mechanics, dynamics and cryomechanics of advanced composite materials, and reliability and durability of micro/nano components and devices.