Adherend thickness influence on fatigue behavior and fatigue failure prediction of adhesively bonded joints

• Published in: Composites. Part A, Applied science and manufacturing Vol. 48; pp. 181 - 191
• Main Authors: Azari, S., Ameli, A., Papini, M., Spelt, J.K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2013; Elsevier
• Subjects: A. Layered structures; Adhesive bonding; adverse effects; Application fields; Applied sciences; B. Fatigue; Crack propagation; Cracks; Curing; D. Mechanical testing; E. Joints/joining; energy; Energy release rate; epoxides; Exact sciences and technology; Fatigue (materials); Fatigue failure; Polymer industry, paints, wood; prediction; Stiffness; Technology of polymers; D. Mechanical testing; A. Layered structures; B. Fatigue; E. Joints/joining; Thermal stress; Epoxy resin; Mechanical properties; Aluminium alloy; Experimental study; Modeling; Finite element method; Fatigue strength; Adhesive joint; Size effect; Numerical simulation; Adhesive; Residual stress; Fracture mode
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2013.01.020

The effect of the adherend thickness, h, on mode-I fatigue behavior of a toughened epoxy adhesive system was examined in terms of the substrate global stiffness and curing residual stress. It was found that a change in adherend thickness from 1.6mm to 12.7mm caused a reduction in the fatigue performance; i.e. the threshold energy release rate decreased and the crack growth rate increased for a given applied energy release rate. Finite element modeling showed that the fatigue results could be explained in terms of an increase in the crack tip stresses and an enlarged plastic zone due to the greater global stiffness of thicker joints. No difference in fatigue behavior was observed for mixed-mode loading at relatively small phase angles; however, it is expected that at higher phase angles the adverse effect of h would be observed.