Multiscale Buckling Modes in the Mechanics of Fiber-Reinforced Plastics

This book is a useful source of knowledge for engineers and scientists in the field of mechanics of deformation and destruction of composite materials.

In Chapter 1 three-dimensional equations of elasticity theory composed for the case of finite displacements and deformations of solids have been analyzed. It is found that the generally accepted simplifications known in the literature and carried out for the case of small deformations result in equations that are considered to be absolutely correct and consistent in all scientific and educational literature on mechanics of deformable solid bodies. However, this conclusion is not sufficiently well-founded as confirmed by formulation and solution of problems on the basis of generally accepted equations for determining both the stress-strain state (SSS) and the critical loads and buckling modes. In Chapter 2 the theoretical and experimental methods for determining the mechanical characteristics of fiber-reinforced plastics (FRPs) based on tensile and compression tests of flat specimens with [0]s , [±90]s, and [±45]2s lay-ups are analyzed. For FRPs with [±45]2s lay-ups, relations are derived for determining the components of lamina strains and stresses in the orthotropy axes of FRP monolayer in terms of axial strains and Poisson ratios of specimens measured in experiments. In Chapter 3 the structure of a unidirectional fibre composite of two types ELUR-P carbon fibre based on KhT-118 cold-curing binder and HSE 180 REM prepreg based on hot-curing binder has been studied. The diameters of fibres and fibre bundles (filaments) of both types of composites have been measured. Based on the results of the analysis of the composite material structure, a refined formulation of the linearised problems of a refined statement of linearized problems on flat internal multiscale buckling modes of a rigid lamina with either fibers or a fiber bundle is presented taking into account their interaction with an epoxy matrix.