Buckling Analysis Of Fiber-Reinforced Laminated Composite Plate With Delamination Under Hygrothermal Environments

This paper employs the basic theory, including mechanics of composite materials,theories of plates and shells and elasticity to research the delamination buckling of thefiber-reinforced, laminated composite plates in hygrothermal environment.Parametric studies are carried out to analyze the influences of geometric parametersand material properties under different environment conditions on the bucklingperformance of the delaminated laminate. The main contents of this thesis are:Analytical model for a composite laminate containing an imbedded delaminationsubjected to the hygrothermal and mechanical loads is established by dividing thedelaminated laminate into four sub-panels. Definite conditions are derived byapplying the equilibrium conditions of the moment and shear force and the continuityconditions of the displacement and the slope at the delaminate fronts. Byintroducing the coefficients of thermal expansion and hygroscopic expansion theconstitutive equations with hydrothermal effects are conducted for the delaminatedlaminates using the mechanics of composite materials. The coefficients of thermalexpansion and hygroscopic expansion are obtained based on a micro-mechanicalmodel for a laminate. Governing equations for the delaminated laminates withhygrothermal effects are derived from the differential equations for the compositelaminates.By considering the continuity property of forces and displacements betweensub-plates, single trigonometric functions are chosen as the solutions of thedeflections of the sub-plates. Substitute the selected functions of deflections into thegoverning equations and separate the variables. The eigenfunction for the bucklingload is derived from a set of linear, homogeneous equation obtained using the definiteconditions. An iterative algorithm is developed using MATLAB program tocalculate the buckling load.Numerical calculations are performed to comprehensively discuss the influencesof the geometric parameters, the material properties, the temperature rise, and the degree of moisture concentration on the buckling performance, including the bucklingload and the buckling modes, of the symmetric cross-plied laminates...