A crack propagation criterion based on local shear strain in adhesive bonds subjected to shear

• Published in: Journal of the mechanics and physics of solids Vol. 44; no. 10; pp. 1669 - 1689
• Main Authors: Chai, Herzl, Chiang, Martin Y.M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.1996; Elsevier
• Subjects: Applied sciences; crack mechanisms; crack propagation and arrest; Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; fracture mechanisms; Fundamental areas of phenomenology (including applications); Mechanical properties; Physical properties; Physics; Polymer industry, paints, wood; polymeric materials; Properties and testing; Solid mechanics; Structural and continuum mechanics; Technology of polymers; crack mechanisms; A; B; crack propagation and arrest; fracture mechanisms; polymeric materials; Interfacial layer; Notched test piece; Precracked specimen; Adhesive joint; Size effect; Mechanical properties; Polymer; Crack arrest; Experimental study; Breaking test; Crack propagation
• ISSN: 0022-5096
• DOI: 10.1016/0022-5096(96)00048-8

Direct observations show that the fracture of thin adhesive bonds subjected to shear is characterized by stable crack propagation along the interface followed by catastrophic growth. Other failure processes are observed during the stable growth phase, including crack kinking, development of a large void at the crack tip and formation of a detrimental interface micro-debond ahead of the main crack. The specific choice depends on factors such as the position of the precrack plane within the adhesive layer, the layer thickness and the loading level. Regardless of the specimen geometry, the entire interfacial crack propagation event is controlled by a single parameter—a critical shear strain at the crack tip that is independent of the bond thickness and the shearing direction but is a (decreasing) function of the crack velocity. The results can be useful in the application of fracture mechanics to the design of microlaminates, composites, traditional adhesive bonding and other technologies in which thin adhesive layers are used.