Hygrothermoelasticity

This book contains results of more than a decade's effort on coupled deformation and diffusion obtained in research performed at the Institute of Fracture and Solid Mechanics, Lehigh University. Despite the overwhelming number of theories on this subject, little is known on the assessment of coupling effects because of the inherent difficulties associated with experimentation. A case in point is couple thermoelasticity, a theory that has remained virtually unused in practice. This is indicative of the inadequacy of conventional approaches. The interdependence of heat, moisture and deformation arises in many engineer­ ing problems of practical interest. Whether these effects are coupled or not depend on the transient character of the boundary conditions. Special attention is given to finding the coupling constants. Invoked is the assumption that the physical parameters should be independent of the specified boundary conditions. They can thus be extracted from known experimental data for situations where coupling effects are relatively weak and then applied to predict strong coupling effects as boundary conditions are altered. This is illustrated for the T300/5208 material commonly used in composites and permits a more reliable evaluation of material behaving under extreme environmental conditions. The lack of this knowledge can often be a major deterrent to the achievement of new technological advances. The reader will recognize that the material in this book does not follow the main stream of research on moisture-temperature diffusion and deformation. Front Matter....Pages I-XII Classical diffusion theories....Pages 1-16 Coupled diffusion of temperature and moisture....Pages 17-45 Analytical solutions of transient hygrothermal stresses in elastic bodies....Pages 47-88 Time dependent finite element formulation of hygrothermal elasticity problems....Pages 89-141 Coupled theory of heat, moisture and deformation....Pages 143-158 Complex variable formulation of hygrothermoelasticity problems....Pages 159-180 Numerical analysis of coupled diffusion and deformation problems....Pages 181-235 The strain energy density function....Pages 237-253 Back Matter....Pages 255-260