Influence of Superstructure-Hull Adhesive Bonds on Longitudinal Bending Performance of Ship Hull Girder

• Investigating the impact of bonded joints between the superstructure and main hull on the global longitudinal bending moment of a scaled ship model. • Progressive failure analyses involving the CZM-approach is used to predict the ultimate bending moment, displacements, and damages in the adhesive layer. • The effect of joint configurations, overlap widths, superstructure materials and lengths, and adhesive material properties are studied. • Comparable results from an adhesively bonded joint for the ultimate bending moment capacity/bending efficiency to a rigid joint. • Understanding the importance of integrating adhesive joint modelling into global hull girder analyses for progressive damage and debonding behavior in the superstructure to hull bonded joints. Adhesive bonding has emerged as a promising joining technique in shipbuilding, particularly for connecting lightweight superstructures to the main hull. While previous studies have extensively investigated the local mechanical behavior of adhesively bonded joints, the influence of such joints on the global longitudinal bending performance of ship hull girders has not been adequately addressed. This gap is especially critical in the context of modern lightweight ship design, where superstructure effectiveness plays a key role in overall structural performance. In this study, the effect of adhesively bonded superstructure–hull joints on the longitudinal bending behavior of a ship hull girder is systematically investigated. A scaled ship model, previously tested experimentally under four-point bending, is adopted as a reference case. Finite element simulations are conducted using Abaqus/Standard, incorporating three-dimensional cohesive zone elements to model progressive damage and fracture in the adhesive layer. Various bonded joint configurations, adhesive material types, overlap widths, superstructure lengths, and superstructure materials are examined and compared with a conventional rigid joint and a bare-hull configuration. The results demonstrate that, with appropriate adhesive joint design, the longitudinal bending moment can reach up to approximately 136% of the bare-hull ultimate bending moment, which is comparable to 145% achieved by a rigid joint. Single- and double-lap bonded joints exhibit ultimate bending capacity and stiffness close to those of rigid connections. These findings indicate that adhesively bonded superstructure–hull joints have the potential to provide an effective and structurally viable alternative to the conventional rigid joint for global hull girder bending performance.