Xfem Modelling of Single-Lap Woven Fabric Kenaf Composites Bolted Joints With Temperature Action

Abstract

The current paper aimed to model failures and fractures in single-lap bolted joints of woven fabric kenaf fiber reinforced polymer (KFRP) composite plate to fail in net-tension. The approach was based on the assumptions that micro-damage events were densely concentrated ahead of the notch tip and crack growth were readily seen along net-tension plane in a self-similar fashion. A 3-D finite element modelling framework were developed to explicitly incorporate bolt clamp-up in a range of KFRP series following tested experimental datasets. Lay-up types, normalized W/d, temperature exposure with constant bolt torque of 5 Nm were considered. It was found that KFRP plates under elevated temperature were stronger than under room temperature due to matrix toughening. Traction-separation relationship was incorported within Extended Finite Element Method (XFEM) framework to model damage within KFRP composite plate by using independent experimental datasets, here incorporates un-notched plate strength, σo and fracture toughness, Gc of all testing lay-ups. Constitutive model used is associated with stress concentration, therefore good agreement between predicted and experimental bearing stress at failure with net-tension failure mode is perhaps not suprising.

Mode-I Interlaminar Fracture Modeling of DCB Composite Laminate using Finite Element Techniques

“…The XFEM was also used to predict several failure mechanisms and was very similar to the mechanisms observed during scanning electron microscopy (SEM) analysis. Ahmad et al [45] used XFEM for single-lap fabric bolted joints made of Kenaf and Kevlar composites and found very good predictions at elevated temperatures. Swati et al [46] used the XFEM technique for transverse damage analysis in CFRP composites and agreed well with the experimental results.…”