Investigation On Strength Assessment Methods For Light Sandwich Composite Structures

Composite materials have been widely used in practical engineering due to its prominent characteristics such as high strength,high elasticity modulus,light weight and anti-corrosion.The application of composite materials in the field of ships has gradually become a hotspot.Compared with the strength evaluation method of isotropic materials,the strength evaluation method of composite materials is much different.In this paper,the strength evaluation method of hull composite structure was mainly studied.1 The mechanics principle and analysis method of composite material and composite sandwich structure were briefly introduced.The structural and mechanical properties of composite materials and composite sandwich structures were analyzed2 A reasonable finite element model of composite hull structure was established.The shell element,solid element and solid continuum element were using to model the composite structure respectively for numerical simulation.The finite element model for the strength evaluation of composite structures was determined by comparing the test results with the simulation results.3 Strength evaluate of composite hull structures.The Tsai-Wu failure criterion was used to evaluate composite structures failure.The progressive damage method was used to investigate the ultimate strength of composite structures.The cohesive element which based on damage and fracture mechanics was adapted to assess interlayer strength.4 The connections of composite hull structures were investigated.A shell-solid mixed model which used 3-dimensional cohesive element was used to analyze the strength of composite bonded joints.Meanwhile,a new 2-dimensional finite model was used to investigate the bolt joint of composite structures.5 Topology optimization analysis of composite ship structure was carried out.The topology of composite laminates is optimized,which provided a new idea for the design of composite hull structure.