Investigation of Tensile Behavior and Influence Factor of a Composite Bolted T‐Joint With New Configuration

ABSTRACT The conventional configuration of composite T‐joints presents a significant challenge for their use in primary load‐carrying structures due to poor damage tolerance capability. Based on a prepreg‐resin transfer molding (RTM) co‐curing technique, this study proposes a new configuration T‐joint comprising an internal laminated skeleton, load‐carrying laminated beams, and an external RTM co‐cured fabric skin. Tensile tests were conducted on bolted specimens. A finite element model was developed, capable of accounting for ply inclination defects, and its validity was verified against experimental results. Experimental and numerical results demonstrate that noticeable delamination damage within the skin causes a marked reduction in the slope of the load–displacement curve, while through‐thickness delamination initiating in the laminated skeleton within the base panel area triggers the onset of load drop. With multiple damage propagation paths, the joint can continuously carry load even after initial damage. Ply waviness defects within the base panel area exhibit noticeable inclination angles; such ply inclination alters the delamination propagation paths within the laminated skeleton and reduces the ultimate tensile load‐carrying capacity by up to 15%. Non‐standard washers effectively redistribute stress concentrations around the inner bolt holes, alter the joint's failure mode, and substantially enhance the capacity of the linear load‐carrying segment.