Speaker

Prof. Herbert Mang, Vienna Uni. Of Technology, Academician of CAE, Austria, Germany, ….

　　Title

　　Time

　　Venue

N202

　　Abstract

The basis of this work is a novel symbiosis of mechanics of solids and spherical geometry to quantify and illustrate the variation of the “non-membrance” percentage of strain energy in the pre-buckling region of elastic structures. The zenith angle of an arbitrary point of a specific curve on an octant of the unit sphere, called buckling sphere, is related to this energy percentage. For the limiting case of buckling from a membrance stress state this curve degenerates to a point, characterized by zero values of both spherical coordinates. For all other stress states the azimuth angle increases with the proportionally increasing load. Its magnitude at the stability limit correlates with a quantity that depends on both the “non-membrance” deformations and of the stiffness of the structure at incipient buckling. The azimuth angle is computed with the help of the so-called consistently linearized eigen-problem, which is solved by means the Finite Element Method. This eigenvalue problem is the basis for a hypothesis for the “non-membrance” percentage of the strain energy. In the theoretical part of the paper, the concept of the buckling sphere is presented. Thereafter, its numerical realization is described. The subsequent numerical investigation consists of four examples, referring to buckling from a membrance stress state, a pure bending stress state, and a general stress state. The practical motive for this research is the intention to investigate the influence of “non-membrance” action just before buckling on the initial post-buckling behavior of elastic structures.     

　　Affiliation

赫伯特·芒主要研究结构工程和计算力学；1977年他与Gallagher教授（国际公认的有限元法开创者之一）一起，揭示了杂交位移法的数值不稳定性。之后，相继创造性地发展了边界元法的奇异积分技术；理论上澄清了冷却塔等结构的稳定性和失效破坏机理，推动了相关结构设计思想的转变；并在多场与多尺度方法及其应用方面有重要建树；是结构工程和计算力学界国际公认的学术权威。 
赫伯特·芒的杰出成就和贡献使其获得多国和多个国际组织的奖励总计16项：1996年获奥地利政府的威廉埃克斯纳奖章；2002获奥地利科技界最高荣誉—科学与艺术荣誉十字勋章； 2004年以其姓氏“Mang”命名了一颗小行星，等等。1992年当选奥地利科学院院士，曾任奥地利科学院院长，并陆续当选欧洲科学院、美国工程院等18个国家或地区的院士或外籍院士。 
赫伯特·芒1981年以联合国特派专家身份，来华对世银资助项目—“大型计算机主机建设”提供了宝贵支持，并在西安、北京进行了有限元法讲座，对中国结构工程计算的进步做出了重要贡献。此后，他访问中国的频率逐渐增加，和国内高校及科研机构建立了广泛的合作关系。先后指导中国十余名研究生和访问学者。 
1995年入选为中国工程院外籍院士。