Damage progression and failure in L-shaped laminated composite bolted joints subjected to quasi-static tensile loading

This paper presents a study on progressive damage development and failure in L-shaped laminated composite bolted joints under tensile loading. Industrial cameras and DIC systems are used to capture the deformation and failure modes in the specimens. A three-dimensional progressive damage model is developed using the commercial code Abaqus/Explicit with an implemented user-defined subroutine VUMAT. The model employs the Maximum Stress Criterion, the Puck Criterion and Johnson-Cook damage models to predict the fibre fracture and matrix cracking in the laminated composites and damage in the titanium alloy bolt, respectively. The results of the simulation are compared with experimental data, with good correlation between the load–displacement response and failure modes being observed. The model accurately captures the onset and propagation of damage in the laminates. This study reveals that matrix cracking and delamination are the dominant failure modes in the joints. Furthermore, the interaction between the bolt and the composite material located close to the hole plays an important role in the failure of the joint. The non-uniform stress distribution in the bolt contributes to joint bending and increased risk of failure.