复合材料螺接修理层压板剩余强度评估

复合材料结构修理是飞机复合材料结构全寿命周期中不可或缺的重要环节。螺接修理传递载荷大,操作简单,易于外场实施。快速估算螺接修理结构的剩余强度,有助于修理参数优化及修理方案的设计。采用基于子模型法的有限元数值分析方法,快速预估螺接修理层压板结构的承载能力。模型中复合材料层压板和金属补片用壳元模拟,螺栓用梁元模拟,采用多点约束技术模拟螺栓与螺栓孔的接触。在整体模型应力分析的基础上,选择高应力区建立子模型,提出0°层点应力准则判断层压板是否破坏,根据粱元剪力的大小用工程方法评估螺栓的强度。分析表明,分析方法建模简单、计算周期短、分析结果与试验结果误差在5%以内,可以满足工程设计和分析要求。

Residual Strength Evaluation of Composite LaminateRepaired with Bolt Joint

Structure repairing is an absolutely necessary step in the whole service life period of aircraft composite structure.Bolted reparing has the advantage of big tranffering load ,easy operation which can be suitable for field repair. Fast evaluating residual strength of bolted repairing laminate is halpful to optimize repair parameters and design. In this paper, tensile residual strength of laminate bolted with metal patch is analyzed using finite element submodel method. In the model, laminate and metal patch are modeled using shell element whereas the fasteners are modeled by beam elements. MPC technique is adopt to simulate the constraint between fastener and hole. The stress analysis is conducted for whole model. High stress area is isolated from whole model and submodel is built Point criterion of 0o laminar is incorporated to obtain failure load. Engineering means is adopt to assess bolt strength by beam shear force. It is shown that the proposed approach can quickly obtain failure load. The errors of predicted result and test result with 5%, which shows the method is helpful to engineering design.