scholarly journals EFFECT OF BONDED COMPOSITE PATCH ON THE STRESS INTENSITY FACTORS FOR A CENTER-CRACKED PLATE

2019 ◽  
Vol 20 (2) ◽  
pp. 211-221 ◽  
Author(s):  
ABDUL AAbid ◽  
Meftah Hrairi ◽  
JAFFAR SYED MOHAMMED Ali ◽  
Ahmed Abuzaid
Keyword(s):  
Stress Intensity ◽  
Loading Condition ◽  
Patch Size ◽  
Mode I ◽  
Intensity Factors ◽  
Adhesive Material ◽  
Element Analysis ◽  
Composite Patch ◽  
Bonded Composite ◽  
Adhesive Thickness

Crack propagation until fracture is an important criterion to predict a structure‘s service life. In order to increase the latter, the cracked component needs to be repaired or replaced. In the present study, a finite element analysis has been carried out to investigate the effects of adhesive thickness, patch thickness and crack length on the passive repair performance of a center-cracked rectangular aluminum plate under mode-I loading condition using an ANSYS package. A comprehensive parametric study shows that the stress intensity factor is influenced by the patch thickness, patch size, adhesive material, and adhesive thickness. ABSTRAK: Penyebaran retak sehingga patah adalah kriteria penting bagi menjangka hayat struktur. Bagi memanjangkan jangka hayat struktur, komponen keretakan perlu dibaik pulih atau diganti. Kajian ini telah menjalankan analisis elemen tak terhingga bagi mengetahui kesan ketebalan pelekat, ketebalan tampalan dan panjang retak pada bahagian keretakan tengah plat petak aluminium yang dibaiki secara pasif, menggunakan pakej ANSYS di bawah beban mod-I. Kajian parametrik yang menyeluruh  menunjukkan faktor tekanan intensif dipengaruhi oleh ketebalan tampalan, saiz tampalan, bahan pelekat dan ketebalan pelekat.

Estimation of Mixed-Mode Stress Intensity Factors with Presence of the Confinement Parameters T-Stress and A3

2016 ◽  
Vol 18 ◽  
pp. 52-57
Author(s):  
Lahouari Fodil ◽  
Abdallah El Azzizi ◽  
Mohammed Hadj Meliani
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Mixed Mode ◽  
Compact Tension ◽  
Mode I ◽  
Mode Ii ◽  
Mixed Mode Fracture ◽  
Intensity Factors ◽  
Element Analysis ◽  
T Stress

A failure criterion is proposed for ductile fracture in U-notched components under mixed mode static loading. The Compact Tension Shear (CTS) is the preferred test specimen used to determine stress intensity factor in the mode I, mode II and the mixed-mode fracture. In this work, the mode I and mode II stress intensity factors were computed for different notch ratio lengths 0.1<a/W<0.7, of the inner radius of notch 0.25mm<ρ<4mm and load orientation angles 0°<α< 90° using finite element analysis. However, a review of numerical analysis results reveals that the conventional fracture criteria with only stress intensity factors (NSIFs) Kρ first term of Williams’s solution provide different description of stress field around notch zone comparing with results introduce the second and third parameter T-stress and A3.

Mode I Stress Intensity Factors for Small Defects in a Large Diameter Threaded Fixing

2020 ◽  
Author(s):  
Adam Towse
Keyword(s):  
Fatigue Crack ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Large Diameter ◽  
Fatigue Crack Initiation ◽  
Mode I ◽  
Intensity Factors ◽  
Element Analysis ◽  
Threaded Connection ◽  
Modelling Methodology

Abstract Mode I Stress Intensity Factors (SIFs) are presented at the surface and depth positions for shallow defects at the root of the male threads of an M130x4 – 6g / 6H threaded connection. The defects range between 1mm and 5mm in depth, and with an aspect ratio (a/b) between 1 (circular) and 0.1 (elongated). For the lowest a/b ratios, the defects approach the shape of an elongated constant depth defect running circumferentially. Such defects may be produced by preferential fatigue crack growth in the circumferential direction, fatigue crack initiation at the root or as a result of thread forming processes. The Mode I opening SIFs have been calculated using linear elastic Finite Element Analysis using contour integration. The modelling methodology was verified by comparison with published SIF solutions for semi-elliptical surface-breaking defects in a plate and also an unthreaded bar. SIFs have been calculated for both membrane and bending loading. The defects were placed at the position of greatest bending stress with the defects symmetric about the bending plane. SIFs have been calculated for different boundary conditions on the female thread side which affect the flow of load out of the stud, and hence the distribution of force in the stud and the resulting SIFs. The results show that if the flow of load in the stud is reversed, simulating reaction through a nut, then the calculated SIFs are higher than the case where the load is not reversed.

Determination of mode I stress intensity factors in surface-flawed plates by scattered-light photoelasticity

1983 ◽  
Vol 18 (3) ◽  
pp. 173-176 ◽  
Author(s):  
J W Holmes ◽  
R A Holmes ◽  
J C Conway
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Scattered Light ◽  
Three Dimensional ◽  
Mode I ◽  
Tension Stress ◽  
Intensity Factors ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The scattered-light photoelastic technique was utilized to determine Mode I stress intensity factors associated with a semi-elliptical surface flaw in a plate subjected to uniaxial tension. Stress intensity factors were experimentally determined for the point of maximum flaw penetration and the point of intersection of the flaw border with the free surface of the plate. Experimental results are compared to those obtained in a three-dimensional finite element analysis with reasonable agreement being shown.

Stress Intensity Factor for Repaired Circumferential Cracks in Pipe With Bonded Composite Wrap

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
F. Benyahia ◽  
A. Albedah ◽  
B. Bachir Bouiadjra
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Criterion ◽  
Three Dimensional ◽  
Element Analysis ◽  
Composite Systems ◽  
Bonded Composite ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The use of composite systems as a repair methodology in the pipeline industry has grown in recent years. In this study, the analysis of the behavior of circumferential through cracks in repaired pipe with bonded composite wrap subjected to internal pressure is performed using three-dimensional finite element analysis. The fracture criterion used in the analysis is the stress intensity factor (SIF). The obtained results show that the bonded composite repair reduces significantly the stress intensity factor at the tip of repaired cracks in the steel pipe, which can improve the residual lifespan of the pipe.

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