The integrity of bonded joints in large composite pipes

The structural integrity of composite pipework systems depends largely on understanding the behaviour of pipe joints under loading. This paper addresses the topic of adhesively bonded taper/taper connections. Both perfect joints and joints with artificial axisymmetric defects (debonds) were investigated in this study. Such geometry and the required property parameters are beyond the scope of conventional analytical theories normally applied to small parallel-sided tubular joints. Therefore, an extensive experimental and numerical programme was necessary to achieve this understanding. The mechanical testing focused on relatively small pipes (100 mm diameter) but the finite element analyses extended to larger pipes (up to 400 mm). Accordingly, the programme resulted in design guidance for the specific range of bonded pipe joints. Additionally, in order to correlate, compare and support the pipe joint analyses, thick steel adherend double-lap shear joints were also studied experimentally and numerically.