A new phenomenological strain gradient theory for crystalline solid is proposed. It fits within the framework of general couple stress theory and involves a single material length scale l cs . In the present theory three rotational degrees of freedom ฯ i are introduced, which denote part of the mate
Couple stress theory for solids
โ Scribed by Ali R. Hadjesfandiari; Gary F. Dargush
- Book ID
- 104018744
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 328 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0020-7683
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โฆ Synopsis
By relying on the definition of admissible boundary conditions, the principle of virtual work and some kinematical considerations, we establish the skew-symmetric character of the couple-stress tensor in size-dependent continuum representations of matter. This fundamental result, which is independent of the material behavior, resolves all difficulties in developing a consistent couple stress theory. We then develop the corresponding size-dependent theory of small deformations in elastic bodies, including the energy and constitutive relations, displacement formulations, the uniqueness theorem for the corresponding boundary value problem and the reciprocal theorem for linear elasticity theory. Next, we consider the more restrictive case of isotropic materials and present general solutions for two-dimensional problems based on stress functions and for problems of anti-plane deformation. Finally, we examine several boundary value problems within this consistent size-dependent theory of elasticity.
๐ SIMILAR VOLUMES
Rayleigh waves in a linear elastic couple-stress medium are investigated; the constitutive equations involve a length parameter l that characterizes the microstructure of the material. With cR = Rayleigh speed, c T = conventional transversal speed and q = wave number, an explicit expression is deriv