Tests and parametric analysis of aluminum alloy bolted joints of different material types

In this paper experimental investigation was conducted on 20 aluminum alloy bolted joints. Based on the tests, three-dimensional refined finite element models were built and verified by the experimental results. By the FE model, extensive parametric analysis was carried out to clarify the influence of aluminum alloy material types (6061-T6, 6063-T5, 6082-T6 and 7A04-T6 which is a kind of ultra-high strength aluminum alloy applied in engineering structures), the diameter of bolt hole and the length of long bolted joints on the loading capacity of aluminum alloy bolted connection. The test results showed that the current design codes including EC9, AA 2010 and GB 50429-2007 underestimate the bearing strength of the joint. According to the results of parametric analysis, a new design method considering the difference of material types was proposed and fit better with the data points than the methods in current specifications; a more precise and detailed suggestion for the bolt hole diameter in aluminum alloy bolted joints was also given. The paper proposed a theoretical model to explain the mechanical mechanism of long bolted joints and gave a new design method for reduction factors of bolt shear force in long joints with different materials of plate and different materials of bolt.