The coefficient of stress concentration about an elliptical hole in a spherical shell

1971 ◽  
Vol 7 (6) ◽  
pp. 680-681
Author(s):  
I. G. Titarenko
2021 ◽  
Vol 8 (1) ◽  
pp. 1-12
Author(s):  
Ashok Magar ◽  
Achchhe Lal

Abstract This paper presents the solution of stress distribution around elliptical cutout in an infinite laminated composite plate. Analysis is done for in plane loading under hygrothermal environment. The formulation to obtain stresses around elliptical hole is based on Muskhelishvili’s complex variable method. The effect of fibre angle, type of in plane loading, volume fraction of fibre, change in temperature, fibre materials, stacking sequence and environmental conditions on stress distribution around elliptical hole is presented. The study revealed, these factors have significant effect on stress concentration in hygrothermal environment and stress concentration changes are significant with change in temperature.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 422 ◽  
Author(s):  
Wenshuai Wang ◽  
Hongting Yuan ◽  
Xing Li ◽  
Pengpeng Shi

Functionally graded material (FGM) can optimize the mechanical properties of composites by designing the spatial variation of material properties. In this paper, the stress distribution of functionally graded panel with a central elliptical hole under uniaxial tensile load is analyzed. Based on the inhomogeneity variation and three different gradient directions, the effects of the inhomogeneity on the stress concentration factor and damage factor are discussed. The study results show that when Young’s modulus increases with the distance from the hole, the stress concentration factor decreases compared with that of homogeneous material, and the optimal design of r-FGM is better than that of x-FGM and y-FGM when the tensile load. In addition, when the associated variation of ultimate stress is considered, the choice of scheme to reduce the failure index is related to the strength-modulus exponent ratio. When the strength-modulus exponent ratio is small, the failure index changes with the index of power-law, which means there is an optimal FGM design. But when the strength-modulus exponent ratio is large, the optimal design modulus design is to select a uniform material that maximizes the modulus at each point. These research results have a certain reference value for further in-depth understanding of the inhomogeneous design for FGM.


1996 ◽  
Vol 63 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Mohamed Salama ◽  
Norio Hasebe

The problem of thin plate bending of two bonded half-planes with an elliptical hole on the interface and interface cracks on its both sides is presented. A uniformly distributed bending moment applied at the remote ends of the interface is considered. The complex stress functions approach together with the rational mapping function technique are used in the analysis. The solution is obtained in closed form. Distributions of bending and torsional moments, the stress concentration factor as well as the stress intensity factor, are given for all possible dimensions of the elliptical hole, various material constants, and rigidity ratios.


Author(s):  
Bogdan S. Wasiluk ◽  
Douglas A. Scarth

Procedures to evaluate volumetric bearing pad fretting flaws for crack initiation are in the Canadian Standard N285.8 for in-service evaluation of CANDU® pressure tubes. The crack initiation evaluation procedures use equations for calculating the elastic stress concentration factors. Newly developed engineering procedure for calculation of the elastic stress concentration factor for bearing pad fretting flaws is presented. The procedure is based on adapting a theoretical equation for the elastic stress concentration factor for an elliptical hole to the geometry of a bearing pad fretting flaw, and fitting the equation to the results from elastic finite element stress analyses. Non-dimensional flaw parameters a/w, a/c and a/ρ were used to characterize the elastic stress concentration factor, where w is wall thickness of a pressure tube, a is depth, c is half axial length, and ρ is root radius of the bearing pad fretting flaw. The engineering equations for 3-D round and flat bottom bearing pad fretting flaws were examined by calculation of the elastic stress concentration factor for each case in the matrix of source finite element cases. For the round bottom bearing pad fretting flaw, the fitted equation for the elastic stress concentration factor agrees with the finite element results within ±3.7% over the valid range of flaw geometries. For the flat bottom bearing pad fretting flaw, the fitted equation agrees with the finite element results within ±4.0% over the valid range of flaw geometries. The equations for the elastic stress concentration factor have been verified over the valid range of flaw geometries to ensure accurate results with no anomalous behavior. This included comparison against results from independent finite element calculations.


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