2D-C/SiC复合材料螺栓连接结构可靠性分析

Reliability Analysis of 2D-C/SiC Composite Bolted Joints

耐高温C/SiC陶瓷基复合材料因加工制造的复杂工艺,其性能参数存在明显的分散性。为了提高复合材料螺栓连接结构的可靠性建模精度,采用渐进损伤分析方法进行强度分析,采用不含交叉项二次响应面函数进行可靠性分析。采用改进的Hashin失效准则与Ye分层失效准则进行渐进损伤分析,分别对结构纤维与基体采用不同的刚度损伤模型,通过有限元仿真获得螺栓连接结构的拉伸极限承载能力,与试验值之间相对误差较小。将2D-C/SiC复合材料的刚度性能参数与强度参数作为随机变量,采用响应面法拟合结构功能函数,通过分析得到结构在拉伸载荷下的失效概率函数,并分析了各材料力学性能参数的灵敏度,发现面内剪切强度对结构可靠性影响较大。

Dispersion of the 2 D-C/SiC composite material performance parameters are a well-known phenomenon characterized because of manufacturing process. To improve thereliability modeling accuracy ofthe 2 D-C/SiC composite material, progressive damage analysis is used for strength analysis, and a quadratic response surface function without cross terms is used for reliability analysis. An improved Hashin failure criterion was adopted for progressive damage analysis, and the material degradation model was proposed for the fiber and the matrix respectively. The relative error between the relative error between the tensile ultimate load of the bolted joints from the finite element analysis and the test date is small.Stiffness parameters and strength parameters were used as random variables.Response surface method was used to fit state function.Structural reliability indicators and failure probability under different loads are obtained. Furthermore, the sensitivity of material’s mechanical properties parameters was analyzed, which found that the interlaminar shear strength has a greater impact on structural reliability.