Goushegir, Seyed MohammadSeyed MohammadGoushegirdos Santos, Jorge F.Jorge F.dos SantosAmancio, SergioSergioAmancio2020-04-282020-04-282016-02-01Composites Part A: Applied Science and Manufacturing (81): 121-128 (2016-02-01)http://hdl.handle.net/11420/5938Welding-based joining technologies have been recently developed for metal-composite lightweight structures. In this work, the welding-based joining technology, friction spot joining, was selected to study the failure and fracture micro-mechanisms of an aluminum-composite single lap joint. Failure analysis suggested that the radial cracks nucleate at the periphery of the bonding area and propagate rapidly until failure of the so-called adhesion zone. Upon further loading the cracks propagate into the transition and plastically deformed zones leading to a reduction of the stiffness of the joint. The findings of the fractography demonstrated a mixed brittle-ductile fracture. Three zones were identified on the fracture surfaces: a smooth and featureless area demonstrating brittle fracture, a quasi-smooth area representing a mixture of ductile and brittle fractures and finally a zone with a highly rough surface implying ductile fracture of the composite part. Further, fiber pull-out and breakage were identified as additional fracture micro-mechanisms.en1359-835X2016121128A. Polymer-matrix composites (PMCs)B. FractureD. FractographyE. Joints/joiningJournal Article10.1016/j.compositesa.2015.11.001Other