A multi-objective optimization procedure for bonded tubular-lap joints subjected to axial loading

A multi-objective optimization method was used to identify globally optimized configurations of bonded tubular single-lap (TSL) joints bearing axial load. Designs for optimal bonding of TSL joints often face conflicting objectives: in general, the main source of conflict centers around minimizing the mass and maximizing the mechanical strength of the joint. This paper presents a three-step method in providing TSL joint configurations which represent the best compromises between these objectives. This method involves creating a fully parameterized finite element model, a parametric study, defining and computing the optimization studies.The parametric study shows that all geometric parameters, aside from the substrates extremity angle, influence the stress profile in the adhesive. Based on the scope of application, the optimization problem is set to consider six optimization variables, four objectives and three constraints. Four studies were conducted with the mass of the joint and the maximum normal, shear, and/or equivalent stress in the adhesive as objectives. The three-step procedure provides 27–173 optimal configurations for all studies and favors mostly joints with a thin layer of adhesive, a long adhesive bond length, and a large inner diameter of internal substrate.