Corrections in numerical methodology to evaluate plasticity induced crack closure along the thickness

• Published in: Theoretical and applied fracture mechanics Vol. 97; pp. 215 - 223
• Main Authors: Garcia-Manrique, J., Camas, D., Parrón-Rubio, M.E., Gonzalez-Herrera, A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.2018; Elsevier BV
• Subjects: Computer simulation; Crack closure; Crack propagation; Cracks; Fatigue; Fatigue cracks; Fatigue failure; Finite element analysis; Fracture mechanics; Materials fatigue; Mathematical models; Methodology; Numerical analysis; PICC; Plastic properties; Stress concentration; Stress intensity factor; Stress intensity factors; Thickness measurement; A; ΔKeff; b; KN; Kttcl; Kmin; E; rpD; Fatigue; K; Kcod; P; CT; R; Stress intensity factor; Kncop; W; Kmax; Finite element analysis; Kttop; PICC; Knccl; FE; KJ
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/j.tafmec.2018.08.004

•K distribution along the thickness has influence in crack closure determination.•Corrections to present numerical methodology are proposed.•The results present variations that validate these recommendations.•The influence is greater in the regions close to the surface.•Convergence between models based on stress (Ktt) and displacement (Knc) is improved. The influence of the three-dimensional effects of the distribution of the stress intensity factor in the numerical calculation of plasticity-induced crack closure is analysed in this paper. The usual methodology assumes a constant distribution of K along the thickness to obtain the effective stress intensity factor of the crack. This assumption should not be transposed to models that intend to observe phenomena in the crack front vicinity, where 3-D effects are a key aspect in the results. Through numerical simulations of both fracture and fatigue of through thickness straight cracks (CT specimen in mode I), the local opening and closure moment of each crack node is obtained and compared with previous one. Corrections are proposed for numerical methodology to obtain Kop and Kcl distribution along the thickness.