scholarly journals Crack-Configuration Analysis of Metal Conductive Track Embedded in Stretchable Elastomer

Micromachines ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 130 ◽  
Author(s):  
Tomoya Koshi ◽  
Eiji Iwase
Keyword(s):  
Crack Configuration

Near-Tip Fields for Penny-Shaped Cracks in Magnetoelectroelastic Media

2006 ◽  
Vol 312 ◽  
pp. 41-46 ◽  
Author(s):  
Bao Lin Wang ◽  
Yiu Wing Mai
Keyword(s):  
Closed Form ◽  
Transversely Isotropic ◽  
Crack Plane ◽  
Axially Symmetric ◽  
Crack Configuration ◽  
Penny Shaped Crack ◽  
Electric And Magnetic Fields ◽  
Shaped Crack ◽  
Transversely Isotropic Solids ◽  
Isotropic Solids

This paper solves the penny-shaped crack configuration in transversely isotropic solids with coupled magneto-electro-elastic properties. The crack plane is coincident with the plane of symmetry such that the resulting elastic, electric and magnetic fields are axially symmetric. The mechanical, electrical and magnetical loads are considered separately. Closed-form expressions for the stresses, electric displacements, and magnetic inductions near the crack frontier are given.

scholarly journals Multicrack Localization in Rotors Based on Proper Orthogonal Decomposition Using Fractal Dimension and Gapped Smoothing Method

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Zhiwen Lu ◽  
Dawei Dong ◽  
Shancheng Cao ◽  
Huajiang Ouyang ◽  
Chunrong Hua
Keyword(s):  
Fractal Dimension ◽  
Proper Orthogonal Decomposition ◽  
Orthogonal Decomposition ◽  
Smoothing Method ◽  
The Finite Element Method ◽  
New Approach ◽  
Rotor Systems ◽  
Crack Configuration ◽  
Proper Orthogonal ◽  
Robust To Noise

Multicrack localization in operating rotor systems is still a challenge today. Focusing on this challenge, a new approach based on proper orthogonal decomposition (POD) is proposed for multicrack localization in rotors. A two-disc rotor-bearing system with breathing cracks is established by the finite element method and simulated sensors are distributed along the rotor to obtain the steady-state transverse responses required by POD. Based on the discontinuities introduced in the proper orthogonal modes (POMs) at the locations of cracks, the characteristic POM (CPOM), which is sensitive to crack locations and robust to noise, is selected for cracks localization. Instead of using the CPOM directly, due to its difficulty to localize incipient cracks, damage indexes using fractal dimension (FD) and gapped smoothing method (GSM) are adopted, in order to extract the locations more efficiently. The method proposed in this work is validated to be effective for multicrack localization in rotors by numerical experiments on rotors in different crack configuration cases considering the effects of noise. In addition, the feasibility of using fewer sensors is also investigated.

Bending Fatigue of Thermal Barrier Coatings

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Robert Eriksson ◽  
Zhe Chen ◽  
Krishna Praveen Jonnalagadda
Keyword(s):  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Base Alloy ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Bending Fatigue ◽  
Crack Configuration ◽  
Lower Load ◽  
Delamination Damage

Thermal barrier coatings (TBCs) are ceramic coatings used in gas turbines to lower the base metal temperature. During operation, the TBC may fail through, for example, fatigue. In this study, a TBC system deposited on a Ni-base alloy was tested in tensile bending fatigue. The TBC system was tested as-sprayed and oxidized, and two load levels were used. After interrupting the tests, at 10,000–50,000 cycles, the TBC tested at the lower load had extensive delamination damage, whereas the TBC tested at the higher load was relatively undamaged. At the higher load, the TBC formed vertical cracks which relieved the stresses in the TBC and retarded delamination damage. A finite element (FE) analysis was used to establish a likely vertical crack configuration (spacing and depth), and it could be confirmed that the corresponding stress drop in the TBC should prohibit delamination damage at the higher load.

FRACTAL ANALYSES FOR A MODEL OF IMPACT FRAGMENTATION

Fractals ◽  
1996 ◽  
Vol 04 (03) ◽  
pp. 393-399 ◽  
Author(s):  
HAJIME INAOKA ◽  
HIDEKI TAKAYASU
Keyword(s):  
Fractal Dimension ◽  
Three Dimensional ◽  
Crack Configuration ◽  
Impact Fragmentation ◽  
Fractal Analyses

We perform fractal analyses for a model of three-dimensional impact fragmentation. The fractal dimension of the whole crack configuration in the system is numerically estimated as D=2.3.

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.

SIFs for Radial Cracks in Annular Discs Under Internal and External Shrinkage Pressure and Constant Angular Velocity

2007 ◽  
Author(s):  
A. Sakhaee-Pour ◽  
A. R. Gowhari-Anaraki ◽  
S. J. Hardy
Keyword(s):  
Finite Element ◽  
Angular Velocity ◽  
Constant Angular Velocity ◽  
Coefficient Of Determination ◽  
Linear Elastic ◽  
Crack Configuration ◽  
Wide Range ◽  
Elastic Fracture ◽  
Radial Cracks

Finite element method has been implemented to predict stress intensity factors (SIFs) for radial cracks in annular discs under constant angular velocity. Effects of internal and external uniform pressure on the SIFs have also been considered. Linear elastic fracture mechanics finite element analyses have been performed and results are presented in the form of crack configuration factors for a wide range of components and crack geometry parameters. These parameters are chosen to be representative of typical practical situations. The extensive range of crack configuration factors obtained from the analyses is then used to develop equivalent prediction equations via a statistical multiple non-linear regression model. The accuracy of this model is measured using a multiple coefficient of determination, R2, where 0 ≤ R2 ≤ 1. This coefficient is found to be greater than or equal to 0.98 for all cases considered in this study, demonstrating the quality of the model fit to the data. These equations for the SIFs enable designers to predict fatigue life of the components easily.

Free Vibration Analysis of FGM Sandwich Beams Containing Edge Cracks

2012 ◽  
Vol 488-489 ◽  
pp. 230-235 ◽  
Author(s):  
Javad Soltani Rad ◽  
Ali Tivay ◽  
Mojtaba Sadighi
Keyword(s):  
Vibration Analysis ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Flexural Vibration ◽  
Functionally Graded ◽  
Finite Element Models ◽  
Sandwich Beams ◽  
Crack Configuration ◽  
Different Depths ◽  
Edge Cracks

This paper presents a vibration analysis of sandwich beams with functionally-graded skins containing edge cracks. Finite Element models of FGM sandwich beams are created with different depths and locations of the edge-cracks, and the first four natural frequencies of the beam are obtained for each crack configuration. The integrity of the data is validated for the FGM skins in comparison to a previously published reference. Finally, an inspection is conducted on the data to show the influences of the location and depth of cracks and material properties on the flexural vibration characteristics of cracked FGM sandwich beams.

scholarly journals Gradient elasticity applied to a crack

2013 ◽  
Vol 22 (5-6) ◽  
pp. 193-201 ◽  
Author(s):  
Iason Konstantopoulos ◽  
Elias Aifantis
Keyword(s):  
Displacement Field ◽  
Crack Tip ◽  
Gradient Elasticity ◽  
Special Treatment ◽  
Mode I ◽  
Crack Configuration ◽  
Robust Version ◽  
Standard Mode

AbstractThe aim of this paper is to investigate the stress and the displacement field of a crack within a robust version of gradient elasticity, focusing at the standard Mode I, II, III problems. Special treatment is attributed to the crack configuration near its tip, deriving the gradient elasticity results that are analogous to the classical asymptotical solutions near the crack tip.

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