A point substitution displacement technique for estimation of elastic notch stress intensities of sharp V-notched bodies

• Published in: Theoretical and applied fracture mechanics Vol. 97; pp. 87 - 97
• Main Authors: Hussain, M.K., Murthy, K.S.R.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-10-2018; Elsevier BV
• Subjects: Benchmarks; Displacement; Finite element; Finite element analysis; Finite element method; Notch; NSIF; Stress intensity factor; Stress intensity factors; Substitutes; V-notch; Stress intensity factor; V-notch; NSIF; Displacement; Notch; Finite element
• ISSN: 0167-8442; 1872-7638
• DOI: 10.1016/j.tafmec.2018.07.010

•A point substitution type technique has been proposed for computation of NSIFs.•The present technique is very simple, robust and efficient.•Certain optimum points in the notch tip elements have been identified.•Notch flank displacements at these optimum points have been employed.•Very accurate NSIFs have been obtained even on relatively coarse meshes.
A simple, robust and efficient point substitution type displacement based technique for finite element estimation of the notch stress intensity factors (NSIFs) of sharp V-notched configurations has been proposed. A novel feature of the proposed technique is that it utilizes the notch flank displacements (of notch tip elements) only at a single point for mode I and at two points for mode II loading conditions for computation of the NSIFs. These critical points of the notch tip elements have been identified using the least square minimization of the error and the slope of the displacement distribution of the notch tip elements. The present technique is simple to implement in the existing code, as it only needs the notch flank displacements at most at two points. The NSIFs of various mode I, mode II and mixed mode (I/II) benchmark problems have been estimated and compared with the available reference solutions. Some additional new results are also presented. The results of the present work show that very accurate NSIFs can be computed even in course meshes made of quadratic elements without the use of any special singular elements at the notch tip.