Strategy of plasticity induced crack closure numerical evaluation

Influence of heat treatment-induced residual stress on residual fatigue life of railway axles

“…These challenging requirements are discussed in various recently published papers related to crack growth in railway axles and used materials, e.g. [8][9][10][11][12][13][14][15][16].…”

Numerical analysis of fatigue crack growth using a plastically dissipated energy factor based model

“…Several researchers also modified the yield stress to flow stress, which can be referred to reference. 23 A comparison of the theoretical and numerical estimation of plastic zone size at the crack tip is shown in Figure 3. The numerical simulation is performed using the established CT specimen model under cyclic load, and the maximum SIF is 881.32 MPamm and load ratio is 0.1.…”

“…For a detailed description, refer to reference. 23 Here, the scheme of Load-Unload-Debond (LUD) is adopted to facilitate the calculation of PDEF. The crack growth simulation is achieved by debonding the nodes at the minimum load, that is, release the constraints of all DOF.…”

“…However, it also has a drawback that the crack closure level is difficult to be determined as the premature contact of the first node, which is caused by the serious deformation of the crack tip element. Many researchers 21-23 defined the crack is closed when the displacement of the first node behind crack tip turns to negative during unloading, and then the related closure force is obtained. The force related to Kc is essential for determining the effective SIF Keff as well as the lower limit of the numerical integration of cyclic J -integral.…”

“…The force related to Kc is essential for determining the effective SIF Keff as well as the lower limit of the numerical integration of cyclic J -integral. 11 Oplt et al 23 investigated the strategy for numerical modeling of the PICC. The method based on the change in the stiffness of specimen is recommended to determine closure level.…”