面内载荷下复合材料整体加筋板破坏过程分析.pdf

1、南京航空航天大学硕士学位论文面内载荷下复合材料整体加筋板破坏过程分析姓名：常园园申请学位级别：硕士专业：工程力学指导教师：许希武2010-12面内载荷下复合材料整体加筋板破坏过程分析 II Abstract As a kind of typical integration structure, the integr

2、al stiffened composite panels were widely used in various fields because of the excellent properties.Under the In-plane loads, composite laminate presented complex failure modes. Due to the deformation inconsistencies ca

3、used by the stiffness mismatch of rib and panel, the interface debonding can easily occur, resulting in failure ahead of time. Therefore, it is significative theoretically and valuable practically that studying the failu

4、re modes of integral stiffened composite panels and the influence of structural parameters on the bearing capacity. A strength analysis model was presented to study the progressive damage of integral stiffened composite

5、panels subjected to in-plane loads by using the nonlinear finite element method. In the model, the debonding failure of the adhesive between skin and stiffener was considered by adding cohesive elements between the shell

6、 elements. Quads failure criteria and Hashin’s failure criteria were adopted to identify the occurring of damage events of the cohesive elements and the composite panels, respectively. Based on ABAQUS, a material degrada

7、tion rule containing continuum damage status variables was presented by user subroutine - umat. The process of damage initiation, propagation and catastrophic failure of three integral stiffened composite panels was simu

8、lated in detail by the proposed mode with the consideration of initial geometric imperfection. The results are well agreed with the experiment data, and can also explain the two different failure phenomena in the experim

9、ents. The in-plane axial stiffness ratio of stiffener and skin was introduced and conducted to study its effects on the carrying capacity and failure modes. For the T-stiffened plates, the effects of equivalent torsional

10、 rigidity, shearing rigidity, equivalent flexural rigidity and in-plane axial stiffness on the buckling load and ultimate strength were studied in detail under shear, combination of compression and shear loads. The resul

11、ts indicate that: in the context of the ply design is reasonable, increasing the stiffness ratio can to some extent improve the unit area bearing capacity of the cross section of stiffened composite panels; within certai