Statics/Dynamics Analysis Of Fibre Metal Laminates Considering Elasto-plastic Effects

In this thesis, mechanical models are presented to investigate the static and dynamic behaviors of Fiber Metal Laminates (FML). Taking the geometric nonlinearity, matrix damage, interfacial damage and elasto-plastic deformation of metal layers in FML into account synthetically, the buckling and postbuckling of FML, buckling of FML including interfacial damage, nonlinear dynamic response of FML including matrix damage and interfacial damage are systematically studied, and the essential character of the mechanical property of FML can be illustrated precisely. The research results are significant not only in the academic but also in the practical engineering. The main results contain as follows.The elastic and elasto-plastic damage constitutive relationships of materials with matrix damage are estabilished. Based on the strain energy equivalence, a constitutive model is established for elastic composites with orthotropic matrix damage. Generally, the total strain increment is making up of elastic strain increment and plastic strain increment, and the elastic strain increment varies linearly with the stress increment, combining the modified Von Mises yield criterion which describes the mixed harding for istropic material with matrix damage, the incremental elasto-plastic damage constitutive equations are derived.Based on the forgoing incremental constitutive equations, introducing the relevant incremental geometric relationship, internal force relationship and equilibrium relationship, considering the geometric nonlinearity, matrix damage, interfacial damage and elastio-plastic deformation of metal layers in FML synthetically, the incremental differential equilibrium equations are established. Furthermore, the elasto-plastic buckling and elasto-plastic postbuckling of FML, the elasto-plastic buckling of FML including interfacial damage, the nonlinear dynamic response of FML under transver force are studied systematically. The Galerkin method, complex trapezoid formula, finite difference method, Newmark method and iterative method are applied to solve the governing equations. The elasto-plastic static and dynamic behaviors of FML are investigated for different parameters, such as geometric parameters, induced load ratio, intial geometric imperfection, damage parameters, load parameters and so on, of which the results reveal the inherent features about the mechanics. The research work in this thesis will certainly not only promote the development of elasto-plastic mechanics and damage mechanics in mechnical modeling research and solution methods, but also be useful for the design, optimization and manufacture of FML.