Development of the distributed dislocation dipole technique for the analysis of closure of complex fractures involving kinks and branches
(English)Manuscript (preprint) (Other academic)
This paper presents the development of the distributed dislocation dipole technique (DDDT) for the analysis of crack surface closure of crack cases involving kinks and branches. Crack cases in which closure occurs are analyzed by reformulating the Bueckner's principle taking the contact stresses at the contacting portions of the crack surfaces into account. Stress intensity factors corresponding to opening and sliding mode of deformation at the crack tips are computed. Three test cases involving kinked and/or branched cracks with at least one of the crack segments undergoing crack surface closure when subjected to remote tensile loading are analyzed. The results obtained from the DDDT are compared to those obtained from the Finite Element Method (FEM) analysis of the same crack cases. This comparison shows that the computation of stress intensity factors for the crack cases involving crack surface closure are less acurate compared to fully open crack cases. However, the stress intensity factors are still computed to an accuracy of within 2 percent if the Jacobi polynomial expansions of at least the sixth order are used to represent the crack surface opening and sliding displacements. Higher order Jacobi polynomials lead to increased accuracy.
Cracks, Dislocation dipoles, Stress intensity factors, Singular integral equations, Crack closure, Contact
Applied Mechanics Reliability and Maintenance Aerospace Engineering Other Materials Engineering
Research subject Materials Engineering; Mechanical Engineering
IdentifiersURN: urn:nbn:se:kau:diva-47128OAI: oai:DiVA.org:kau-47128DiVA: diva2:1045139