Imperfection sensitivity of pressured biopolymer spherical shells



题目2Imperfection sensitivity of pressured biopolymer spherical shells

报告人:Prof. C.Q. RUUniversity of Alberta





    Dr. Ru is currently a Professor in department of mechanical engineering, University of Alberta, Canada. Dr. Ru received his doctorate in solid mechanics at Peking University (China), and then worked in the Institute of Mechanics, Chinese Academy of Science and held a number of visitor/research positions in several universities in Italy, USA and Canada. He joined the University of Alberta in 1997 and became a Professor in 2004. Dr. Ru’s past research areas include plastic buckling of structures, mechanics of elastic inclusions, electroelastic mechanics, and some applied mathematics problems related to solid mechanics. Besides traditional areas of solid mechanics, his recent research interests include solid mechanics at micro/nano scales, cell biomechanics, and dynamic ductile fracture.


    Imperfection sensitivity is essential for various mechanical behavior of biopolymer shells of high geometric heterogeneity and thickness non-uniformity.In this presentation, a simpler refined shell model recently developed for biopolymer spherical shells is used to study imperfection sensitivity of pressured biopolymer spherical shells. Simpler axisymmetric deformation is examined first, and followed by a study of non-axisymmetric deformation with two-mode interaction. The present formulation and method are validated by comparing our results to established known results for the special case of classical elastic spherical shells. One of our major conclusions is that most typical biopolymer spherical shells (such as some ultrasound contrast agents and spherical virus shells) are only moderately sensitive to geometric imperfections due to their relatively small radius-to-thickness ratios as compared to classical elastic thin shells characterized by much larger radius-to-thickness ratios, although fewer biopolymer spherical shells of relatively larger radius-to-thickness ratios can be very sensitive to geometric imperfection.