复合材料3钉单搭连接有限元模拟与钉载分布

进行了复合材料一铝合金三钉单搭连接单向拉伸试验，测量了层合板面内位移、应变和离面位移随载荷的变化关系，建立了复合材料多钉单搭连接的三维累积损伤有限元模型，计算与试验对比结果表明，该模型可模拟大范围损伤发生之前的承载特性。采用试验和数值模拟相结合的方法研究了复合材料一金属三钉单搭连接钉载分布情况，结果表明：试验用复合材料-铝合金三钉单搭连接，螺栓1承载比例最高，螺栓3次之，中间螺栓的承载比例最低，并且螺栓承载比例在加载过程中基本保持不变；随着金属连接板刚度的增加，螺栓1的承载比例增加，螺栓3承载比例降低，中间螺栓2的承载比例变化较小，层合板离面位移减小；金属板配合间隙变化对钉载分布影响很小，但层合板的离面位移随配合间隙的增大而增大。

Finite element model and load distribution analysis for three-bolted single-lap composite joints

The uniaxial tension experiments of 3-bolted, single-lap, composite-aluminum joints were conducted to measure the in-plane displacement, strain and out-of-plane displacement vs. applied load. A 3D progressive damage finite element model (FEM) was developed to simulate the bearing behavior of the multi-bolt, single-lap composite joints. The comparison between the FEM and experimental result shows that the model could predict the bearing behavior until the widespread damage appeared. The pin-load distribution was analyzed by both FEM and experimental methods. It can be concluded that: for the sample used for experiment, the most proportion of load is transferred by bolt 1, followed by bolt 3, and the bolt 2 transferred the least proportion of load. The proportion of load transferred by each bolt is constant during the load-applied process. With the increasing of the metal plate stiffness, the loads transferred by bolt 1 increase and bolt 3 decreases; the load transferred by bolt 2 alters little; the out-of-plane displacement decreases significantly. The variation of clearance has minor effect on the proportion of load transferred by each bolt, but out-of-plane displacement increases with the clearance increasing.