Overload Effects During Fatigue Crack Growth in Nodular Cast Iron - simulation with an Extended Strip-yield Model

Abstract

Within this paper an extended strip-yield model for the simulation of fatigue crack growth in nodular cast iron under variable amplitude loading is presented. The model is based on the conventional strip-yield model and by using an additional boundary condition the formerly observed crack acceleration effects after applied overloads can be described. A comparison of experimental results and simulation shows the applicability of the extended strip-yield model for single spike overloads as well as for random load sequences.

Determination of the Effective Elastic Modulus for Nodular Cast Iron Using the Boundary Element Method

“…The Young's modulus was 171 GPa, averaged over the four tests. The values of the modulus of elasticity that others obtained for NCI are 187 GPa [33], 172 GPa [15], and 179 GPa [34], demonstrating good agreement with the present values. …”

Micromechanisms of fracture in nodular cast iron: From experimental findings towards modeling strategies – A review

“…This model predicts in accordance with experimental findings (compare Section 2.4.1), that for high void volume fractions, being representative for the graphite content in NCI, the crack may propagate stably by cleavage in the upper ductile-brittle transition region. A modified strip yield model, which has certain similarities with a cohesive zone, was used in [134] to simulate fatigue crack growth in NCI including the known overload effects. …”