复合材料层压板铆接修补剩余强度评估

RESIDUAL STRENGTH EVALUATION OF COMPOSITE LAMINATES REPAIRED BY RIVETED METAL PATCH

机械连接修理是复合材料结构主要修补方式,由于拆卸方便、传递载荷大等优点,在结构维修中得到广泛应用。对修补结构进行强度评估是保证修理效果进行参数优化的必要步骤。本文采用数值模拟方法对两种铆接修补层压板的拉伸剩余强度进行了评估分析。层压板用壳元模拟,紧固件用梁元模拟,紧固件与孔的约束用多点约束技术模拟。在Abaqus商业化有限元分析软件及其二次开发平台上,利用用户自定义场(USDFLD)的方法对复合材料性能进行多级衰减。分析结果与试验结果一致性良好,破坏载荷的预估值与试验值误差在6%之内。分析方法对复合材料机械连接修理设计有一定的借鉴作用。

Fastened joint repair is a main repair method for composite structure with advantages of easy disassembling, high load transferring capacity. It is important to evaluate the residual strength in repair design process. In this paper, the tensile load bearing capacity of metal riveted repair laminates were evaluated by numerical simulation using progressive failure analysis method. Laminate was modeled using shell element whereas the fasteners were modeled by beam elements. MPC technique was adopt to simulate the constraint between fastener and hole. The USDFLD subroutine was used to degrade material stiffness by multi-lever manner while damage occurred. The failure analysis results including failure mode, failure load are in good agreement with test results. The errors of predicted failure loads are with 6% , which shows the proposed method is helpful to composite fastened joint repair design.