Crack extension in a material whose resistance to deformation increases with increasing strain

✍ Scribed by E. Smith

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 428 KB
• Volume: 130
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(90)90075-e

✦ Synopsis

This paper addresses the problem of crack extension in a material such as rubber, animal membrane or human membrane where the resistance to deformation shows a marked increase when the strain exceeds a critical level, i.e. the stress-strain curve is J-shaped and convex with respect to the strain axis. Analysis of a very simple simulation model, which incorporates the discreteness of the material's structure, shows that the work of fracture or the effective fracture energy 7 EFF for crack extension can be large. It can be considerably greater than the value obtained by regarding it as the area under the force-law curve, as would be the case if the material were regarded as a continuum. The analysis elucidates the contributory effects of the tensile behaviour of the material and the (shear) intercommunication of the component elements. The theoretical predictions accord with experimental observations that 7EFF is large for a material having a J-shaped stress-strain behaviour. Furthermore, the results suggest that it is the J-shaped tensile behaviour of an element and not the shear intercommunication between elements that is primarily responsible for the large 7EFF values.