Numerical analysis of the structural performance of adhesive T-joints under bending loads

Abstract

T-joints are a good alternative to conventional adhesive joints, such as single-lap joints, due to their ability to efficiently transfer bending, compressive, shear, and tensile loads between the T-profile stiffener and the base plate, all while maintaining cost-effectiveness. However, for widespread adoption, a comprehensive understanding of the joint strength and damage mechanisms is essential. Therefore, this study aims to numerically analyse the structural performance of adhesive T-joints subjected to 3-point bending loads using two-dimensional (2D) finite element models, and cohesive zone modelling (CZM) to simulate the behaviour of the adhesive. CZM validation was also accomplished by comparing the joints' behaviour with experimental data. Numerically, peaks of peel stresses at the overlap edges were observed, with sharp gradients toward the inner bond region, as well as shear stresses due to the geometric discontinuity. Adhesives with higher stiffness provide higher peak values of peel and shear stresses, while more ductile ones lead to higher peak loads. The CZM was successfully validated with experiments, and a correlation was observed between energy dissipation and damage propagation, according to a non-symmetrical pattern, and for conditions that minimize the system's functional energy.