A computationally efficient cohesive zone model for fatigue

Abstract

A cohesive zone model has been developed for the simulation of both high and low cycle fatigue crack growth. The developed model provides an alternative approach that reflects the computational efficiency of the well‐established envelop‐load damage model yet can deliver the accuracy of the equally well‐established loading‐unloading hysteresis damage model. A feature included in the new cohesive zone model is a damage mechanism that accumulates as a result of cyclic plastic separation and material deterioration to capture a finite fatigue life. The accumulation of damage is reflected in the loading‐unloading hysteresis curve, but additionally, the model incorporates a fast‐track feature. This is achieved by “freezing in” a particular damage state for one loading cycle over a predefined number of cycles. The new model is used to simulate mode I fatigue crack growth in austenitic stainless steel 304 at significant reduction in the computational cost.

Computational Modeling of Intergranular Crack Propagation in燼n營ntermetallic Compound Layer

“…The magnitudes of the parameters vary widely, ranging from MPa to GPa for traction, J to kJ for energy, and nm to mm for separating displacement. The effect of various parameters in the cohesive zone law on the macroscopic failure of materials has been examined in the literature [22][23][24][25]. It is commonly believed that the failure behavior is dominated primarily by the energy that controls separation; thus, cohesive energy is the most important parameter.…”

Modelling the time‐dependent mechanical behaviour of clay rocks based on meso‐ and micro‐structural viscous properties

“…As shown in Figure 7, an interface damageable cohesive model including an elastic, a constant cohesion, a softening and a complete decohesion behavioural phases is used 50 . The model provides some flexibilities arising from the four parameters {$$D_{t/n}^0$$, $$D_{t/n}^1$$, $$\delta _{t/n}^c$$, $$c_{t/n}^{max}$$} representing, respectively, the damage initiation, the cohesion softening initiation, the critical relative displacements for complete decohesion, and the maximum cohesive forces.…”

Frequency-dependent cohesive-zone model for fatigue

“…For the conventional loading-unloading hysteresis damage model ∆ is equal to 1. However, if the extrapolation scheme is applied to fast-track the crack propagation, the increment ∆ is set to have an integer value significantly greater than one for computational practicality [19].…”

“…An extrapolation scheme to fast-track the crack growth rate has recently been developed by the authors of this work for speeding up the loading-unloading hysteresis damage model [19], although frequency dependence is not considered.…”