Secondary bending effects in progressively damaged single-lap, single-bolt composite joints

Static tensile experiments and progressive failure simulations of single-bolt, single- and double-lap joints were carried out to comparatively investigate secondary bending effects, which present significant eccentric-loading phenomena in single-lap joints but are almost non-existent in symmetric double-lap joints. Progressive damage models of single-lap and double-lap joints were established, from which the numerical predictions were found to be in good agreement with the experimental outcomes. Experimental macro-scope failure patterns and seven numerical micro-scope failure modes obtained from the progressive damage analyses were presented for the two types of joints. The effects of secondary bending on the mechanical degradation and failure mechanism of single-lap joints were revealed. Some characterizations of secondary bending in the joints, such as a characterized parameter on the AGARD points, joint deformations and contact states, were quantitatively traced during the total progressive damage process. All these characterizations increased the understanding of the effects of secondary bending on the failure process of a single-bolt, single-lap joint. Keywords: Composite, Bolted joint, Secondary bending, Progressive damage analysi