Assessing plastically dissipated energy as a condition for fatigue crack growth

Implementation of a plastically dissipated energy criterion for three dimensional modeling of fatigue crack growth

“…[11] for predicting cyc lic crack propagation rate is founded on the premise that, from a continuum perspective, fatigue crack advances by cyclic material degradation in a process zone near the crack tip (see, for example, Ref. [23]).…”

“…The iterative procedure for establishing the discrete propaga tion rate, Daj N , which is the discrete equivalent of the continuous crack propagation rate, da/dN, after each load cycle as described in [11] is summarized here for clarity. At the end of a load cycle, the accumulated plastically dissipated energy, W p , is determined by evaluating this quantity in a discrete domain (the dissipation domain, D) in front of the crack tip, as shown in Fig.…”

“…They observed no sig nificant differences between the three schemes with respect to crack opening load levels. In this study, following numerous other researchers [11,[29][30][31], crack propagation is accomplished by releasing the constraints on the current crack front nodes at the end of the load cycle, i.e., at minimum load.…”

“…An alternative approach to predict fatigue crack propagation rate directly from FE simulations based on the plastically dissi pated energy criterion was proposed in Ref. [11]. Results from a two dimensional (2D) plane strain analysis were presented for fa tigue crack growth rate changes due to negative load ratios, as well as single and multiple tensile overloads.…”

“…[11] to predict crack propagation in low cycle fatigue regime based on the plastically dissipated energy. 1 The 3D model enables the prediction of tunneled crack profiles.…”