Stress Intensity Factors for Radial Cracks in a Pre-Stressed, Thick-Walled Cylinder of Strain-Hardening Materials

1983 ◽  
Vol 105 (2) ◽  
pp. 117-123 ◽  
Author(s):  
S. L. Pu ◽  
P. C. T. Chen
Keyword(s):  
Stress Intensity ◽  
Strain Hardening ◽  
Yield Condition ◽  
Function Technique ◽  
Maximum Pressure ◽  
Simple Method ◽  
Fatigue And Fracture ◽  
Useful Life ◽  
Radial Cracks ◽  
High Internal Pressure

A simple method which combines the weight function technique and finite element results is used to obtain mode I stress intensity factor solutions for radially cracked cylinders subjected to a high internal pressure. The method is especially effective for cylinders having residual stresses due to a manufacturing pre-stress process to increase the maximum pressure the cylinder can contain and to improve the cylinder’s useful life against fatigue and fracture. The method is quite general for various assumptions involving the plastic stress-strain relations, the yield condition, the strain-hardening, and the compressibility of the cylinder material.

scholarly journals The influence of pavement degradation caused by cyclic loading on its failure mechanisms

2016 ◽  
Vol 11 (3) ◽  
pp. 179-187 ◽  
Author(s):  
Marcin Gajewski ◽  
Stanisław Jemioło
Keyword(s):  
Yield Condition ◽  
Limit Load ◽  
Flow Rule ◽  
Smooth Approximation ◽  
Simple Method ◽  
Plastic Properties ◽  
The Road ◽  
Plastic Materials ◽  
Number Of Cycles ◽  
Elastic Plastic Materials

In this paper, a simple method is proposed to estimate capacity of multilayered road structure including the degradation of the elastic and plastic properties of the constituent materials. In the study boundary value problem modeling interaction of wheels with road surface layer in the frame of large deformation theory for elastic-plastic materials was formulated. Plastic properties of the material were described by the flow rule un-associated with yield condition. The Coulomb-Mohr yield condition was assumed and the potential for plasticity is its smooth approximation. In addition, in constitutive modeling the dependence of the Young’s modulus and cohesion of the material from the number of cycles is taken into account. This paper presents qualitative findings in relation to mechanical behavior of the road structure, i.e., for example, the development of plastic zones with increasing load for un-degraded and degraded materials. In addition, a parametric study of the influence of the degradation ratio of the elasticity and plasticity properties for road structure failure mechanism (limit load value) was made.

Solution to the Rolling Problem for a Strain-Hardening Material by the Method of Discontinuities

1951 ◽  
Vol 18 (1) ◽  
pp. 90-94
Author(s):  
Alice Winzer
Keyword(s):  
Strain Hardening ◽  
Method Of Characteristics ◽  
Continuous Solution ◽  
Discontinuous Solution ◽  
Yield Condition ◽  
Hardening Material ◽  
Discontinuity Surfaces ◽  
Plane Plastic ◽  
Thin Plastic ◽  
Good Agreement

Abstract The problem of drawing and rolling of a thin plastic sheet between cylindrical guides was investigated recently by H. I. Ansoff, under the assumption that the material is in a state of plane plastic flow and obeys the Saint Venant-Mises yield condition (1, 2). He determined the stress distribution along the sheet by the method of characteristics and also by the method of discontinuity surfaces and found good agreement between these results as well as with experimental data. Since the computations required for the discontinuous solution are considerably less laborious than those necessary for the continuous solution, the same type of problem, but now under the assumption that the material displays strain-hardening, will be analyzed by the method of discontinuities. It seems reasonable to expect that the results so found constitute a close approximation to results based upon a continuous solution.

An Integral Technique to Evaluate Opening Mode Stress Intensity Factors for Embedded Planar Cracks of Arbitrary Shape

1985 ◽  
Vol 9 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M.A.A. Khattab ◽  
D.J. Burns ◽  
R.J. Pick ◽  
J.C. Thompson
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Arbitrary Shape ◽  
Intensity Factors ◽  
Simple Method ◽  
Aspect Ratios ◽  
Opening Mode ◽  
Integration Techniques ◽  
Mode Stress ◽  
Coarse Grids

In this paper, techniques are developed to handle the integrable singularities of the integral proposed by Burns and Oore for the estimation of opening mode stress intensity factors for embedded planar defects of arbitrary shape. The hybrid numerical-analytical integration techniques developed consider separately two crack front zones and one interior zone of the crack surface. Parameters are established for the sizing of the integration elements within each zone. Studies of elliptical defects with aspect ratios between 1 and 10 demonstrate the accuracy and efficiency of this procedure for computing opening mode stress intensity factors. A simple method which compensates for the quadrature error associated with computationally inexpensive, coarse grids is outlined.

Residual Stress Redistribution Caused by Notches and Cracks in a Partially Autofrettaged Tube

1981 ◽  
Vol 103 (4) ◽  
pp. 302-306 ◽  
Author(s):  
S. L. Pu ◽  
M. A. Hussain
Keyword(s):  
Residual Stress ◽  
Stress Intensity ◽  
Residual Stresses ◽  
Stress Intensity Factors ◽  
Classical Method ◽  
Thermal Simulation ◽  
Intensity Factors ◽  
Crack Face ◽  
Simple Method ◽  
Crack Configuration

A simple method is provided for the computation of the redistribution of residual stresses and the stress intensity factors due to the introduction of notches and cracks in a partially autofrettaged tube. Numerical results of several crack and notch problems are obtained by the method of thermal simulation. These results are shown to be in excellent agreement with those obtained from the classical method of superposition. The new method based on thermal simulation is easier to apply and it avoids the alternate method of superposition requiring cumbersome distributed crack face loadings for each crack configuration.

Estimation of Stress Intensity Factors due To Welding Residual Stresses for Circumferentially Cracked Pipes

2012 ◽  
Author(s):  
Chang-Young Oh ◽  
Ji-Soo Kim ◽  
Yun-Jae Kim ◽  
Young-Jin Oh ◽  
Kyoungsoo Lee ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Residual Stresses ◽  
Stress Intensity Factors ◽  
Finite Element Analyses ◽  
Intensity Factors ◽  
Crack Face ◽  
Simple Method ◽  
Weld Geometry ◽  
Nonlinear Stress

This paper proposes a simple method to estimate stress intensity factors due to welding residual stresses. In this study, finite element analyses for circumferentially cracked pipe are performed to calculate stress intensity factors. Four cracked geometries and two types of weld geometry are considered. KI-solutions for the nonlinear stress distribution on the crack face were determined in accordance with codes and standards. The results are compared with KI-solutions from finite element results. It is found that proposed simple method agrees well with FE results.

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