题目1：软物质准晶――化学，物理和材料科学的交叉学科
报告人：范天佑教授（北京理工大学）
时间：2017年3月17日15:00
地点：航空宇航学院学术报告厅（A18-529）
主办单位：机械结构力学及控制国家重点实验室、科协、航空宇航学院
固体准晶1984年报导发现，2011年发现者获得化学诺贝尔奖。2004年起在液晶，聚合物，胶体，表面活性剂中发现准晶，被称为软物质准晶。软物质准晶是软物质和准晶这两个不同学科的交叉和边缘学科，引起化学，物理，材料科学和数学等不同专业研究者的兴趣，目前从化学，物理，材料科学和数学等不同方向去研究，正处在热潮中。本讲座从化学，物理，数学和计算物理，计算数学的角度去讨论，主要讨论了软物质准晶广义流体动力学原理，同时以大量的计算结果，揭示它的动力学性质以及和它同固体准晶在物理和力学上的巨大差别。
题目2：Imperfection sensitivity of pressured biopolymer spherical shells
报告人：Prof. C.Q. RU（University of Alberta）
时间：2017年3月17日16:00
地点：航空宇航学院学术报告厅（A18-529）
主办单位：机械结构力学及控制国家重点实验室、国际交流合作处、科协、航空宇航学院
报告人简介：
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.
报告内容简介:
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.