基于弹簧质量模型的复合材料螺接修理载荷传递计算方法

复合材料螺接修理具有操作简便，对连接件表面处理的要求不高，施工快速、性能可靠等优点，在复合材料的临时修理、尤其是战伤修理中应用较为广泛。然而其修理设计过程较为复杂，难以满足工程快速定参的需要。在螺接接头弹簧质量模型的基础上，针对蒙皮和补片等宽的情况，提出了一种复合材料螺接修理结构载荷传递比例计算方法。通过引入载荷按刚度分配的原则对模型进行修正，将模型进一步推广到蒙皮宽度大于补片宽度的情况。然后讨论了模型中不同弹簧刚度的计算方法。给出了采用细观力学方法以及均匀化方法等计算含损伤蒙皮等效刚度的计算方法，推导得到了规则排列多列螺栓连接中各排螺栓等效刚度的计算方法，并证明该刚度满足叠加原理。最后，以含圆形损伤孔的复合材料蒙皮板的螺接修理问题为例，对模型进行了考核，并与有限元法（FEM）预测结果进行了对比。结果表明：模型预测结果与有限元结果吻合较好，预测误差最大为7.7%。采用该模型可以高效、准确地实现复合材料螺接修理的分析设计。

A calculation method for load transfer in bolted repair of composite laminates based on spring-mass model

Composite bolted repair provides the advantages of easy operation, fast processing and reliable performance, making it a preferable repair method for damaged composite structure, especially for battle damage repair. However, the repair design process is complex, and it is difficult to meet the need for rapid determination of parameters. In this paper, a simple method for estimate the load transfer in composite bolted repair is proposed based on the spring-mass model. The skin and the patch are first assumed to be of the same width. The model is then modified and applied to the bolted repair joint where the width of the skin is larger than that of the patch by introducing the principle of load transfer in materials according to their stiffness. The calculation method for equivalent stiffness of the damaged skin is discussed integrating the micromechanical method and the homogenization method. The calculation method for the equivalent bolt stiffness is given and proven to meet the principle of superposition for regular arrangement of bolts. The proposed method is validated by applying it to analyze the repair of damaged composite skin plate with a circular hole. The method is also compared with the finite element method (FEM). The results show that the predicted results by the proposed method agree well with those by the FEM, with the maximum error being 7.7%. The model could be used for efficient and accurate design and analysis of composite bolted repair joint.