Rapid evaluation of notch stress intensity factors using the peak stress method: Comparison of commercial finite element codes for a range of mesh patterns

Three‐dimensional numerical analyses, using the finite element method (FEM), have been adopted to simulate fatigue crack propagation in a hollow cylindrical specimen, under pure axial or combined axial‐torsion loading conditions. Specimens, made of Al alloys B95AT and D16T, have been experimentally tested under pure axial load and combined in‐phase constant amplitude axial and torsional loadings. The stress intensity factors (SIFs) have been calculated, according to the J‐integral approach, along the front of a part through crack, initiated in correspondence of the outer surface of a hollow cylindrical specimen. The crack path is evaluated by using the maximum energy release rate (MERR) criterion, whereas the Paris law is used to calculate crack growth rates. A numerical and experimental comparison of the results is presented, showing a good agreement in terms of crack growth rates and paths.

J = \frac{B}{E} \cdot ((), K_{I}^{2} + K_{II}^{2}) + \frac{1}{2 G} \cdot K_{III}^{2},

where B = (1 − ν 2 ) for plane strain and 1 for plane stress and G is the tangential modulus of elasticity.…”

Section: Numerical Analysesmentioning

confidence: 99%

A computational strategy for damage‐tolerant design of hollow shafts under mixed‐mode loading condition

Lepore

Yarullin

Maligno

et al. 2018

“…If these conditions are fulfilled, the mode I PSM calibration constant is equal to K * FE = 1.38 and, once fixed an arbitrary average FE size d such that the mesh density ratio a / d is at least equal to 3, Equation estimates K 1 through the linear elastic peak stress σ I,peak with a scatter band of ±3%. Recently, the PSM has been calibrated also for other FE software packages different from Ansys in case of plane FE models …”

Section: The Psm Analytical Backgroundmentioning

confidence: 99%

“…In Ansys, such a procedure is called average from principals ( AVPRIN ,1 setting). Several software packages make both the average from components technique and the average from principals technique available, one of them being the default setting (in Ansys, it is the average from components technique) and the other one being able to be activated by the FE analyst …”

Section: Calibration Of the Psm In The Sysweld Environmentmentioning

confidence: 99%

The peak stress method to calculate residual notch stress intensity factors in welded joints

Colussi

Ferro

Berto

et al. 2017

Self Cite

According to the recent literature, the intensity of linear elastic residual stress\ud fields near the toe region of a welded joint can be quantified by the residual\ud notch stress intensity factors (R‐NSIFs). The computational effort required to\ud compute the R‐NSIFs implies strong limitations of applicability in practice,\ud owing to the very refined meshes needed and to the non‐linear transient nature\ud of welding process simulations, especially in 3‐dimensional numerical models\ud of large structures. The peak stress method (PSM) is a design approach that\ud takes care of the industrial needs of rapidity and ease of use. According to the\ud PSM, it is possible to evaluate the R‐NSIFs by using the peak stress calculated\ud at the point of singularity with coarse finite element (FE) models. While the\ud PSM was originally calibrated by using the Ansys FE code, in the present contribution,\ud the PSM has been calibrated to rapidly estimate the R‐NSIFs in the\ud Sysweld FE environment

“…Moreover, researchers have also investigated mixed mode fracture criteria using NSIFs using a sharp V‐notched Brazilian disk (SV‐BD) specimen. Due to the application of the NSIF in the above failure criteria, many researchers used various numerical techniques to estimate the NSIFs of sharp V‐notched configurations, such as finite element method (FEM), extended FEM, fractal‐like FEM, boundary element method, body force method, boundary collocation method, and distributed dislocation method . On the other hand, Zhao and Hahn determined the NSIFs of sharp V‐notches from the SIFs of the corresponding crack geometries directly.…”

Section: Introductionmentioning

confidence: 99%

Calculation of mixed mode (I/II) stress intensities at sharp V‐notches using finite element notch opening and sliding displacements

Hussain

Murthy

2019

In this paper, a simple, robust, and an efficient technique has been proposed for accurate estimation of mixed mode (I/II) notch stress intensity factors (NSIFs) of sharp V‐notched configurations using finite element notch opening and sliding displacements at the selected number of nodes along the notch flanks. Unlike the crack problems, displacement field is rarely employed in the notch problems due to complexities introduced by the presence of rigid body displacements. One of the main emphasis of the present work is to neatly bypass these rigid body displacements and develop a simple approach for accurate computation of the NSIFs so that it can be easily incorporated in the existing code. Several benchmark problems have been analyzed. The results obtained using the present method show excellent agreement with the solutions available in the literature. Some new results have also been reported in the present work.