复合材料层合板螺栓连接失效的数值模拟

NUMERICAL FAILURE SIMULATION OF BOLT-LOADED COMPOSITE LAMINATE

基于二维有限元模型,对复合材料层合板螺栓连接的破坏失效问题利用刚度降低的方法来模拟损伤演化过程。在ABAQUS有限元软件中加入损伤子程序对螺栓连接强度和失效模式进行数值计算。计算结果表明,该方法能够较好地反映和符合实验结果。对计算结果分析发现,对于正交铺层,剪切非线性不明显,非线性和线性分析得到的计算结果差别比较小;而对于角铺层,剪切效应比较显著,非线性和线性分析两种计算结果差别很大,而且非线性分析比较适合于角铺层层合板的计算。配合间隙的大小对挤压强度会产生很大的影响,随着配合间隙的增大,连接强度大大降低。对于不同的配合间隙,出现严重损伤的位置不同。间隙小时,在远离螺栓孔中心线处损伤最大;间隙大时,损伤在靠近螺栓孔中心线位置最为严重;间隙越大,损伤峰值越高。

Based on the 2D model, the user subroutine USFLD has been programmed for ABAQUS to simulate the damage evaluation in the composite laminate, The numerical results show that the present method can predict the bear strength and demonstrate the failure mode of the bolt-loaded laminate very well, After analyzing the results, as for the cross-ply laminate, the shear non-linearity effect is not evident, both the non-linear analysis and the linear analysis can he applied to predict the strength and the failure mode of the cross-ply laminate, hut as for the angle-ply laminate, the difference between the above two methods is very large, and the non-linear analysis is more fit for this laminate, The clearance between the bolt and the hole affects the ultimate strength of the laminate to a great extent, The hear strength decreases with the clearance increasing, At the same time. the clearance can affect the distribution and degree of damage in the hoh-loaded laminate,