Elasticity (physics)

Abstract: : In some circumstances, elastic-plastic deformation occurs in which both components of strain are finite. Such situations fall outside the scope of classical plasticity theory which assumes either infinitesimal strains or plastic-rigid theory for large strains. The present theory modifies the kinematics to include finite elastic and plastic strain components. For situations requiring this generalization, dilatational influences are usually significant including thermo-mechanical coupling. This is introduced through the consideration of two coupled thermodynamic systems: one comprising thermo- elasticity at finite strain and the other the irreversible process of dissipation and absorption of plastic work. The present paper generalizes a previous theory to permit arbitrary deformation histories.

Abstract: A nuclear magnetic resonance imaging (MRI) method is presented for quantitatively mapping the physical response of a material to harmonic mechanical excitation. The resulting images allow calculation of regional mechanical properties. Measurements of shear modulus obtained with the MRI technique in gel materials correlate with independent measurements of static shear modulus. The results indicate that displacement patterns corresponding to cyclic displacements smaller than 200 nanometers can be measured. The findings suggest the feasibility of a medical imaging technique for delineating elasticity and other mechanical properties of tissue.

Abstract: Abstract This book provides a critical review of the equilibrium elastic properties of rubber, together with the kinetic-theory background. It is suitable for the non-specialist and the emphasis is on the physical reality embodied in the mathematical formulations. Polymer science had developed greatly since the second edition of this text in 1958, and the two main advances – the refinements of the network theory and associated thermodynamic analysis, and the development of the phenomenological or non-molecular approach to the subject – are both reflected in the structure of this third edition.