预紧力对层合板螺栓连接强度的影响研究

预紧力的大小对连接件的连接强度具有较大的影响。在ABAQUS软件环境下建立层合板螺栓连接结构的三维有限元模型，引入改进的Hashin三维失效判据，并提出了一种新的结构刚度分区退化模型，分别计算了预紧力存在的条件下凸头螺栓和沉头螺栓连接情况下单搭接层合板的失效情况。计算结果与试验结果的对比表明：采用这种刚度退化模型的计算结果较为精确；预紧力对凸头螺栓连接和沉头螺栓连接的失效情况影响不同，合适的预紧力可以提高层合板的极限强度，过大的预紧力不利于结构的承载。

Research on Influence of Pre-tightening Force to Laminate Bolt Joint Strength

Pre-tightening force is of great influence on linking strength of connector. A 3D model of composite laminates with bolted joint is created by using the software ABAQUS. The improved Hashin, the 3D failure cri teria, is also introduced, and a new degradation model called Partition Degradation Model is put forward. By using this method, the failure situation of single lap laminated plates with the connection of raised head bolt and countersunk head bolt are calculated separately in the condition of existence of pre-tightening force. Compared with the test results, it shows that the computing results are more accurate by using this degradation model. The pre-tightening force is of different influence on failure situation between raised head bolt and countersunk head bolt. It also indicates that the ultimate strength of laminate will be enhanced with appropriate pre tightening force and excessive pre-tightening force will impair the load carrying capacity of the structure.