Study on the effect of adhesive thickness of single lap joints using acoustic emission and FEA

Composite structural members, which are widely used in applications such as aerospace, automobiles, marine, architecture etc, have attracted extensive attention in the past decades. Adhesive bonding is a practical method for joining composite materials, though it has low shear and tensile strength and joint efficiency. An experimental and numerical study was carried out to identify the ultimate strength and failure modes of bonded single lap joints at two different overlap thicknesses. In the present work, the effect of bonded lap thickness on the tensile strength of lap joints is investigated experimentally and numerically. Acoustic emission tests were carried out to analyse the matrix cracking (adhesive failure), thin-layer cohesive failure and fibre tear failure during the loading process. The strength and structural integrity of the bonded joints are investigated by the acoustic emission parameters. The ANSYS FEA tool has been utilised to investigate the stress distribution characteristics of a composite bonded lap joint under tensile loading. The experimental results are compared with FEA results using ANSYS. © 2013 Publishing Technology.