An improved GBJM method and its application in bolt load distribution and load capacity analysis of composite structures with bolt group

In order to analyze the bolt load distribution and load capacity of composite structures with bolt group, an improved global bolted joint model (GBJM) method was developed firstly, and then the method was applied to predict the bolt load distribution and load capacity of multi-bolt composite joint structures. The prediction values and test results were compared. Results show that the predicted multi-bolt load distribution coincides well with the test results before the onset of composite hole-edge damage; as for the prediction of the load capacity of structures, this method seems to be conservative with 15% lower than the test results. Meanwhile the improved model has two significant advantages: one is high computational efficiency with a 75% rise compared to the three-dimensional finite element models for the calculations of bolt load distribution; the other is that this method is effective for the prediction of failure loads of composite structures with bolt group.