Plastic strip model of cracked weld joint with residual stresses

• Published in: Theoretical and applied fracture mechanics Vol. 30; no. 1; pp. 51 - 63
• Main Author: Liu, Q.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.09.1998; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Joining, thermal cutting: metallurgical aspects; Metals. Metallurgy; Welding; Rupture; Theoretical study; Dislocation; Plasticity zone; Crack opening displacement; Compressive stress; Tensile stress; Welded joint; Stress distribution; Size effect; Plasticity; Crack tip; Heat affected zone; Residual stress
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/S0167-8442(98)00045-7

The effect of residual stresses on the fracture behavior of a cracked weld joint is studied by making use of the continuous dislocation formulation. Considered are the plastic zone length of the strip model zone and the opening displacement of a crack that is normal to both weld line and base metal boundary; they depend on the character of the yield stresses for the base metal (BM), weld material (WM), and heat affected zone (HAZ). The crack driving force is found to increase with the tensile residual stress while crack initiation and growth are suppressed if the residual stress is compressive. Moreover, the plastic zone and crack opening displacement are found to decrease linearly with the HAZ yield strength as the HAZ width is increased for HAZ yield strength greater than that of BM.