Concept of stress dead zone in cracked plates: Theoretical, experimental, and computational studies

Abstract

This paper presents a study on stress dead zone implications and its characterization with uniaxial tensile testing on MT polycarbonate plate specimens. To obtain the experimental solution, digital image correlation (DIC) is used. Numerically, based on LEFM, the problem is solved using advanced discretization techniques, finite element, and meshless methods. Considering stress dead zone notion, it aims to determine alternative analytical solution of the SIF. Thus, the compliance method is adopted, which is associated with the specimen's dead zone region that does not involve the cracking resistance. Hence, LEFM formulations complying with strain energy release rate criterion are assumed. A proper comparison is made amongst results obtained from all theoretical, experimental, and numerical analyses. Furthermore, this work focuses on the variational fields' evaluation and, in particular, verification on the theoretical assumption of dead zone characteristics. The obtained results support adopted methodologies and are encouragingly robust and cost‐effective.

High‐stress fatigue crack propagation in thin AA2024‐T3 sheet material

“…The effect of the plastic wake from the propagating crack is an inherent part of DIC results; however, it cannot be revealed separately as it is not possible to distinguish between elastic and plastic strains without further assumptions. In addition, Figures 6 and 7A show that the limited specimen length and long crack result in a large stress dead zone with reduced stresses/strains (blue) in the centre of the specimen 23 . This fact is well‐captured in the simulation model for the linear‐elastic calculations of the stress intensity factors.…”

“…Computational algorithms enable the determination of the J‐integral and the stress intensity factors by exploiting the characteristic crack tip field 18,19 or by using integration techniques 20–22 . In addition, DIC shows features that influence the entire deformation field of the specimen, for example, the stress dead zone in the centre of MT specimens between the crack tips 23 . These are valuable methods for investigating crack propagation in more detail and for identifying relevant crack driving mechanisms 24–26 …”

A fracture study of slanted cracks using the stress dead‐zone hypothesis

“…The material properties of PC optical grade were considered as Young's modulus: E = 2.38 (GPa), Poisson's coefficient: υ = 0.37 and yield strength of σ y = 62.70 (MPa). 20 Uniaxial tensile loading was executed using an Instron ® E1000 equipment.…”

Stress intensity factor evaluation for central oriented cracks by stress dead‐zone concept

“…Moreover, in the evaluation of the associate compliance of the cracked plate, it seems that this detail did not draw the attention from researchers. In this regard, Farahani et al 7 carried out a study on the SDZ model in the field of the LEFM. It was emphasized that this model is quite accurate in order to characterize the SIF.…”