Reserch On The Elastic Modulus Degradation Law Of Composite Cross-ply Symmetric Laminate

In recent years,the composite material are widely used in aviation,aerospace and clean energy in areas.The fatigue property of composite material structure has become an important factor of restricting its development.In the fatigue process of composite material,its internal failure mode is complicated.The research on the fatigue properties degradation law of the composite material is becoming a hot spot of its fatigue behavior direction.In this paper,the main research is divided into three parts.The first part is under fatigue load,the one-way slabs' transverse attenuation degradation law of modulus of elasticity.From the perspective of the composite material failure mode analysis of the factors which affect the transverse elastic modulus attenuation of fatigue.Focuses on the effects of fatigue load and angle of fiber laying.Build a description of the one-way slab transverse elastic modulus attenuation of fatigue quantitative models and verified by experimental results.The second part is the study of orthogonal symmetric laminated board under fatigue loading,the crack propagation rate is influenced by the load redistribution To explain the influence of load redistribution in between the layers,and proof the crack extend of damage layer by inhibition of adjacent layers.To modified the material properties fatigue degradation model by influence function.We can get the elastic modulus of fatigue degradation model of damage layer.In order to verify the rationality of the model,using the orthogonal symmetric laminated plate tensile elastic modulus as a validation.The calculation results contrast the test results,Theoretical analysis and experimental results was coincident.Influence function can describe the relationship between layer laminated plates.The third part using ABAQUS UMAT subroutine functions.The single elastic modulus decline model is put in the finite element model calculation,compared with the test results show that the finite element numerical solution better match the orthogonal symmetric laminate tensile fatigue degradation law of modulus of elasticity.The paper builds the finite element analysis model can better predict orthogonal symmetric laminate composite materials tensile modulus of elasticity fatigue degradation rule.