FINITE ELEMENT MODELLING OF ADHESIVELY BONDED FRP COMPOSITE TUBULAR JOINTS

Adhesively bonded FRP composite tubular joints are increasingly adopted in lightweight structural applications due to their high strength-to-weight ratio, corrosion resistance, and design flexibility. However, their structural performance is governed by complex interactions between material orthotropy, joint geometry, and damage mechanisms. Under service conditions, these joints may experience adhesion failure at the adherend–adhesive interface or cohesion failure within the adhesive layer, which can significantly reduce stiffness and load-carrying capacity. This chapter presents a comprehensive numerical framework for the intact and joint fracture (adhesion/cohesion failure) modelling of adhesively bonded FRP composite tubular joints. Finite element based intact and fracture modelling provides an effective means to capture these mechanisms, enabling prediction of critical locations, failure loads, and post-fracture response. Initially, the intact joint behavior is characterized to obtain the stress distribution using three-dimensional finite element models incorporating orthotropic material properties of the FRP adherends. Joint fracture initiation regions can be identified with the application of suitable failure criteria. Subsequently, fracture modelling can be introduced through the incorporation of pre-embedded adhesion and cohesion fractures at their respective location. The outcomes provide valuable insights into the failure mechanisms of adhesively bonded FRP composite tubular joints and offer a reliable predictive tool for their analysis and design.