Simulation of fatigue crack growth under consideration of cyclic plasticity

Abstract

In this paper a procedure to simulate the crack growth under consideration of elastic‐plastic material behavior by means of the finite element method is described. Within this procedure, after each increment of crack advance, the structure is remeshed and the status variables, such as the components of the backstress‐tensor and the plastic strains, are transferred from the old mesh to the new one. Due to mapping of the variables, improper conditions are possibly prevailing at the beginning of the new analysis, which has to be captured by the used material routine. The main focus of this paper is to describe these necessary numerical adjustments.

Advanced Methods of Fatigue Assessment

“…4.26, has been developed (Zerres 2010;Zerres et al 2011;Zerres and Vormwald 2012). The software tools perform a complete remeshing of the structure after having identified a crack increment.…”

“…Another example of the influence of cyclic plastic deformation on the crack geometry has been published (Zerres et al 2011). A thin-walled tube specimen Fig.…”

“…4.45 Thin-walled tube specimen (a) with circumferential crack starter notch (b); crack initiation locations at notch edge under torsional loading; (Zerres et al 2011) (or bending moment) which may then be applied proportionally or non-proportionally. Superimposed on the torsional moment, the tube may be loaded by a tension force Fig.…”

Classification of Load Sequence Effects in Metallic Structures

“…More complex approaches point at identifying effective, i.e. closure-free ranges by finite element based fatigue crack growth simulations [27][28][29][30].…”

Fatigue of engineering structures under combined nonproportional loads: An overview

“…Here, the shortcoming of this method, which is based on linear‐elastic fracture mechanics, is clearly visible; effects due to plasticity, which play a major role for the fatigue crack growth, are not explicitly captured but at the utmost implicitly in line with the crack growth law. To overcome this shortcoming, Zerres et al presented a procedure to simulate the crack growth under consideration of elastic‐plastic material behaviour by means of the finite element method (see Figure ). Similar to the finite element methods based on linear‐elastic fracture mechanics, the structure is remeshed after every increment of crack advance.…”