Failure Characterization For Details Of Integrated Composite Stiffened Panels

Composite is used abroad in engineering machineries. In order to utilize the carrying capacity of composite more effective, it is necessary for us to research the failure mechanism of composite structure. The main research object of the thesis is stiffened composite panels, as it is a typical composite structure. In this thesis, on the basis of many experiments and finite element simulations, the failure mechanism of stiffened composite panels has been researched, and the characterization of failure mechanism was obtained. The main content of this thesis is summarized as follows:1. The history, actuality and applications of the failure characterization for typical composite construction has been introduced,and some ideas for Six-point bending experiment and Seven-point bending experiment were proposed. The testing specimens and setups of Six-point bending experiment and Seven-point bending experiment were designed, on the basis of the finite element analysis and constituted experiment's approach.2. Four-point bending experiment, Six-point bending experiment and Seven-point bending experiment were simulated by ABAQUS finite element code, and ABAQUS'owned cohesive element and the quadratic nominal stress, the energy release rate rule were used. Those bending experiments,which were based on the finite element analysis,has been researched.3. Furthermore, the failure mechanism of stiffened composite Panels had been researched by calculated a series of Six-point bending experiment's and Seven-point bending experiment's models. On the basis of the result of experiment and finite element simulation, the failure envelop of the typical structural element and the failure characterization for stiffened composite Panelss were obtained.4. Some suggestions for the intensity designs of composite structure were captured by researching those characterizations of the failure mechanism in this thesis.