Energy release rate, the crack closure integral and admissible singular fields in fracture mechanics

One of the assumptions Linear Elastic Fracture Mechanics is that crack faces are traction-free or, at most, loaded by bounded tractions. The standard Irwin’s closure integral, widely used for computation Energy Release Rate, also relies upon this assumption. However, there practical situations where load acting on boundaries singular. This case, instance, in hydraulic fracturing, fluid inside exerts singular tangential tractions its front. Another example unbounded case a rigid line inclusion (anticrack) embedded into an elastic body. In such situations, classical integral fails to provide correct value Rate. paper, we address effects occurring when square-root act boundary defect solid and generalisation integral. latter yields Rate allows broad applications, including, among others, soft materials containing stiff inclusions, shear bands cracks characterized Gurtin-Murdoch surface stress elasticity. We present results most general form, six Stress Intensity Factors present: three them SIFs corresponding Modes I-II-III computed under assumption homogeneous conditions surfaces, while other associated with admissible (those lead finite ERR value). It demonstrated approach resolves ambiguity using same SIF’s terminology cases open benefits.