Investigation on Indentation Cracking-Based Approaches for Residual Stress Evaluation

Abstract

Vickers indentation fracture can be used to estimate equibiaxial residual stresses (RS) in brittle materials. Previous, conceptually-equal, analytical models were established on the assumptions that (i) the crack be of a semi-circular shape and (ii) that the shape not be affected by RS. A generalized analytical model that accounts for the crack shape and its change is presented. To assess these analytical models and to gain detailed insight into the crack evolution, an extended finite element (XFE) model is established. XFE analysis results show that the crack shape is generally not semi-circular and affected by RS and that tensile and compressive RS have different effects on the crack evolution. Parameter studies are performed to calibrate the generalized analytical model. Comparison of the results calculated by the analytical models with XFE results reveals the inaccuracy inherent in the previous analytical models, namely the neglect of (the change of) the crack aspect-ratio, in particular for tensile RS. Previous models should therefore be treated with caution and, if at all, used only for compressive RS. The generalized model, on the other hand, gives a more accurate description of the RS, but requires the crack depth.

Additive Manufacturing of Bulk Metallic Glasses—Process, Challenges and Properties: A Review

“…High levels of residual stresses can cause delamination, distortion, and cracking in the additively manufactured parts [151], especially for BMGs with low ductility. Xing et al [41] investigated the level of residual stresses in an AMZ4 bar fabricated on a comb-shape support structure, using finite element (FEM) simulations (see Figure 22).…”

Determination of Mechanical and Fracture Properties of Silicon Single Crystal from Indentation Experiments and Finite Element Modelling

“…Identification of elastic and/or elasto-visco-plastic constitutive laws from indentation tests in terms of general theoretical framework of inverse problems solution has been described in [5,6]. With respect to brittle materials, cohesive zone FE simulations of indentation cracking have been performed e.g., in [7][8][9][10] to investigate the crack morphology, the change of crack length with indenter shape, a quantitative evaluation of the threshold load for indentation fracture, and to explore a limitation of analytical models such as Lawn-Evans-Marshall model [11]. For indentation crack initiation and propagation modelling a cohesive interface consisting of cohesive elements is placed in the plane of potential cracking and only mode I type crack is considered.…”

“…Namely, the crack front is found as a result of the solution of the boundary value problem. Moreover, the influence of residual stresses developing under the indent due to inelastic compressive behaviour of brittle materials [10,[14][15][16][17] is more reliably captured. Some care is needed with respect to the elasticity of the cohesive interface, specifically one should avoid double-counting the elasticity-once in the cohesive law and a second time as part of the bulk behaviour.…”

Effect of Mechanical Properties on Wear Resistance of Si3N4 – SiC Ceramic Composite

“…Wear mechanisms are important at evaluation of wear of silicon nitride in friction couple either ceramic-ceramic or ceramic-metal. Some theoretical models were proposed [12,13] and subsequently specified and verified experimental [14][15][16]. Abrasive wear is the most common wear of Si 3 N 4 based ceramic materials.…”