Stress intensity factors for corner cracks in single‐edge notch bend specimen by a three‐dimensional weight function method

The weight function method is a powerful method for the determination of key parameters of stress intensity factors and crack opening displacements that are fundamental for crack analyses in fracture mechanics. The method has a remarkable computational efficiency without compromising solution accuracy and is especially suited for cracks in real‐world components with complex stress gradients. A critical issue for successful development and reliable application of the weight function method is how to achieve verifiable and high solution accuracy. This paper provides several reflections on the current state of the art in weight function methods, including a brief historical perspective and description of several analytical and numerical weight methods, with main focus on the two‐dimensional (2D) analytical approaches. A variety of typical application examples are presented. A platform for point‐by‐point accuracy assessment by using the Green's functions is established on a completely independent numerical approach with validated accuracy. Rigorous and systematic verification of the accuracy levels of different 2D analytical weight function approaches are conducted using several benchmark crack geometries. The sources of inaccuracy of different analytical weight function methods are analysed. A brief account on weight function methods for analysing three‐dimensional (3D) crack problems with arbitrary univariant and bivariant stress distributions is provided.

Section: Wfms For 3d Crack Problemsmentioning

confidence: 90%

A review and verification of analytical weight function methods in fracture mechanics

2019

“…The SSWFM has been employed by Zhao et al and the writers' team for determination of SIFs of surface/ corner cracks with various 3D crack configurations and loadings, for example, in plates, at circular hole and semi-circular notch, under tension, bending, and wedge loadings. References [33,35,36,53,54] are some example applications. A large amount of normalized 3D SIFs for various elementary stress distributions, such as the power stress (σ(x, y)/σ 0 = (x/c) n , σ(x, y)/σ 0 = (y/a) n , n = 0 $ 3 or 4), have been determined by using SSWFM and tabulated recently in the Wu-Xu book of WFMs.…”

Section: Assessment Of Solution Accuracy and Applicationsmentioning

confidence: 99%

A review of three‐dimensional weight function methods for the analysis of various surface/corner crack problems

Xu,

2023

The stress intensity factor (SIF) is the foundation of fracture mechanics analysis. Accurate determination of SIFs is at the very heart of damage tolerance design and fatigue crack growth life prediction. The weight function method (WFM) is a powerful method for SIF‐determination involving complex load conditions. This article presents a review of the historical development over the past five decades and the current state‐of‐the‐art in three‐dimensional (3D) WFMs. The discussions are focused on the slice synthesis weight function method (SSWFM) and the point weight function method (PWFM). The powerfulness of the 3D WFMs is shown by a variety of examples with complex part‐through crack configurations under uni‐ and bi‐variant loadings. Solution accuracy is verified by comparisons of SIFs with various numerical methods. Use of the substitute geometry concept to expand the capability of 3D WFMs for solving real‐world engineering 3D crack problems is demonstrated. Some remaining challenges are briefly discussed.

“…Various methods have been used in the past for SIF evaluation. Among them, many are based on analytical models, finite element analysis, boundary element method, three‐dimensional weight function method, distributed dislocation technique . Experimental measurements through special kinds of strain gauges have been also used.…”

Section: Introductionmentioning

confidence: 99%

Fatigue crack growth of multiple interacting cracks: Analytical models and experimental validation

Galatolo

Lazzeri²

2017

This article deals with the fatigue propagation of multiple cracks in finite width holed panels, which are typical of aircraft structural components. Theoretical studies in the literature have been considered and critically analyzed. Some of them have been translated into analytical models and implemented in a computer code. To check the effectiveness of the used models, a fatigue testing campaign has been conducted on six different configurations of notches and cracks. The comparison between experimental results and those obtained from the implemented models has shown a good agreement