(10/19) 서울대학교 지구환경시스템공학부 초청 강연

서울대학교 지구환경시스템공학부 초청 강연 서울대학교 지구환경시스템공학부에서는 New Zealand의 University of Auckland에 계시는 Ian F. Collins 교수님을 모시고 Some Applications of Thermomechanics to geomechanics 라는 제목으로 초청강연을 개최합니다. 관심있는 분들의 많은 참여를 부탁드립니다. ▨주제 : Some Applications of Thermomechanics to Geomechanics ▨일시 : 2001년 10월 19일(금) 오후 2시 ▨장소 : 서울대학교 에너지자원신기술연구소 ▨강연자 : Prof. Ian F. Collins (University of Auckland/New Zealand) ▨초록 With the exception of recent developments in geo-environmental engineering, thermodynamics is not generally seen as an important tool in modeling the behaviour of soils, sands and granular materials. After all soils do not get hot when tested in the lab nor in the field. However, in addition to heat , thermodynamics deals with another very important physical quantity - namely entropy . Entropy controls the amount of energy, which is dissipated during a deformation. Thus when a structure - be it made of soil, rock, concrete or steel - fails - by the development of excessively large deformations, it is the entropy of the structure which undergoes a sudden change. In recent years there has been a number of major developments in the subject of thermomechanics, which have been widely employed in problems involving metallic materials and have been particularly successful in developing new models of damage . The main objective of this talk is to demonstrate that these ideas throw new light on some of the outstanding issues in modeling geomaterials. A systematic procedure for constructing constitutive models will be described, starting from the form of the dissipation function. Topics covered include the choice of state variables, the difference between plastic work and dissipation, the derivation of yield conditions and flow rules. Some well known, and widely used existing models will be shown to violate the Second Law of Thermodynamics. In consequence some new models will be proposed, which exhibit non-associated flow behaviour, non-convex yield loci, pre-peak softening and static liquifaction, and other features of the observed behaviour of geomaterials.