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 variation of in-plane displacement, strain and out-of-plane displacement with the applied load. A 3D progressive damage finite element model (FEM) was developed to simulate the bearing behavior of the multi-bolted single-lap composite joints. The comparison between the FEM and experimental result shows that the model can predict the bearing behavior before the widespread damage. The pin-load distribution was analyzed by FEM and experimental methods. It can be concluded that the most proportion of load is transferred by bolt 1, followed by bolt 3, and the bolt 2 transferred the least proportion of load for the sample used for experiment. 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 decrease transferred by bolt 3, and the loads transferred by bolt 2 change little. While the out-of-plane displacement decreases significantly. The variation of clearance has minor effect on the proportion of load transferred by each bolt, but the out-of-plane displacement increases with the clearance increasing.