复合材料层合板螺栓连接失效分析

利用ABAQUS软件,加入失效分析程序对层合板螺栓连接挤压强度进行分析.本文提出一种合理的材料刚度退化方法模拟材料失效过程,计算中采用Hashin准则为失效判据,考虑了接触关系,材料逐步失效以及几何非线性等因素.研究结果表明,对压缩失效与拉伸失效采用不同的刚度退化方法能较准确地描述材料失效状态;孔径与板厚度比(D/t)对螺栓孔挤压强度影响较大,随着D/t值减小,螺栓孔挤压失效区域向螺栓孔中心线位置集中.

Failure Analysis of Composite Bolted Joints

An analysis based on two-dimensional finite element model was performed to evaluate the bearing strength of bolted composite joints.The objective of the study were to find a reasonable degradation rule to simulate the progressive failure.The user subroutine USDFLD was programmed for ABAQUS to add Hashin failure criteria to the model.Progressive failure,contact at the bolt-hole interface and large deformation theory were taken into account.After analyzing the results,the given degradation rule predicted the bearing strength well and it could simulate the failure status well.Diameter/thickness(D/t) affects the bearing strength of the hole.The bearing strength increases with D/t decreasing,and the failure area is close to the symmetric line of the hole.The results were compared with experimental data and good correlation observed.