Transient thermal stress intensity factors of bimaterial interface cracks using refined three-fringe photoelasticity

2009 ◽  
Vol 44 (6) ◽  
pp. 427-438 ◽  
Author(s):  
B Neethi Simon ◽  
R G R Prasath ◽  
K Ramesh
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Thermal Stresses ◽  
Bimaterial Interface ◽  
Intensity Factors ◽  
Fringe Order ◽  
Colour Image ◽  
Opening Mode ◽  
Single Colour ◽  
Transient Thermal

Transient thermal stresses of a bimaterial specimen with interface edge cracks subjected to heating along an edge is analysed by refined three-fringe photoelasticity (RTFP). Whole-field, noise-free, fringe order estimation using a single colour image is made possible using RTFP combined with colour adaptation. The stress intensity factors (SIFs) of the interface crack are determined through a multiparameter overdeterministic system of equations by a least-squares approach using experimental data collected automatically. The transient SIFs are found to peak to a higher value than in steady state, and the opening mode is found to be dominant. An increase in thermal load causes the crack to propagate, and this is easily visualized on the basis of quantitative fringe order data available for the whole field. The SIFs of a propagating crack are found to be low. The study shows that the crack propagates easily when the opening mode is dominant.

A Green’s Function for the Stress-Intensity Factors of Edge Cracks and Its Application to Thermal Stresses

1969 ◽  
Vol 91 (4) ◽  
pp. 618-624 ◽  
Author(s):  
A. F. Emery ◽  
G. E. Walker ◽  
J. A. Williams
Keyword(s):  
Stress Intensity ◽  
Green’S Function ◽  
Green's Function ◽  
Stress Intensity Factors ◽  
Thermal Stresses ◽  
Rectangular Plates ◽  
Intensity Factors ◽  
Edge Cracks ◽  
Predicted Values ◽  
Transient Thermal

A Green’s function for the computation of stress-intensity factors for edge cracks in rectangular plates is given for any distribution of stress in the uncracked plate which is tensile over the crack length. The function is used to compute stress intensity factors for transient thermal stresses produced by sudden cooling of one edge. Experimentally measured stresses and stress-intensity factors are given and shown to be in good agreement with the predicted values.

Computation of Thermal Stress Intensity Factors for Bimaterial Interface Cracks Using Domain Integral Method

2009 ◽  
Vol 76 (4) ◽  
Author(s):  
Ratnesh Khandelwal ◽  
J. M. Chandra Kishen
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Thermal Loading ◽  
Thermal Stresses ◽  
Body Force ◽  
Bimaterial Interface ◽  
Intensity Factors ◽  
Linear Elastic ◽  
Domain Integral ◽  
Bimaterial Interface Crack

The concept of domain integral used extensively for J integral has been applied in this work for the formulation of J2 integral for linear elastic bimaterial body containing a crack at the interface and subjected to thermal loading. It is shown that, in the presence of thermal stresses, the Jk domain integral over a closed path, which does not enclose singularities, is a function of temperature and body force. A method is proposed to compute the stress intensity factors for bimaterial interface crack subjected to thermal loading by combining this domain integral with the Jk integral. The proposed method is validated by solving standard problems with known solutions.

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.

Three Dimensional Modeling of Inclined Surface Cracks in FGM Coatings

2009 ◽  
Vol 631-632 ◽  
pp. 109-114
Author(s):  
Sadik Kosker ◽  
Serkan Dag ◽  
Boray Yildirim
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Mixed Mode ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Transient Behavior ◽  
Correlation Technique ◽  
Mixed Mode Fracture ◽  
Intensity Factors ◽  
Parametric Analyses

This study presents a three dimensional finite element method for mixed-mode fracture analysis of an FGM coating-bond coat-substrate structure. The FGM coating is assumed to contain an inclined semi-elliptical crack at the free surface. The trilayer structure is examined under the effect of transient thermal stresses. Strain singularity around the crack front is simulated by utilizing collapsed wedge-shaped singular elements. The modes I, II and III stress intensity factors are computed by applying the displacement correlation technique and presented as a function of time. Four different FGM coating types are examined in the parametric analyses which are metal-rich, ceramic-rich, linear variation and homogeneous coatings. The results provided illustrate the influences of the FGM coating type and crack inclination angle on the transient behavior of the mixed-mode stress intensity factors.

The Singularity of Stress near the Tip of a Crack Perpendicular to an Elastically Mismatched Bimaterial Interface

2014 ◽  
Vol 574 ◽  
pp. 48-52
Author(s):  
Ming Song ◽  
Hao Yong Li ◽  
You Tang Li ◽  
Min Zheng
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Finite Element Methods ◽  
Stress Intensity Factors ◽  
Bimaterial Interface ◽  
Intensity Factors ◽  
Material Combination ◽  
Single Material

This Based on the elastic theory of a crack perpendicular to and terminating at bimaterial interface, a generalized expression of the stress intensity factor is provided for a crack in single material and a crack perpendicular to bimaterial interface, finite element methods are used to calculate the stress intensity factors. The influences of the material combination and crack length on the the stress intensity factors were investigated. Results show that when the crack terminates at bimaterial interface, singular order ofKIis different from that of single material, and the values ofKIincrease with increasingE1/E2andμ1/μ2.

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