scholarly journals The Investigation of Crack's Parameters on the V-Notch Using Photoelasticity Method

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
M. Saravani ◽  
M. Azizi

V-notches are the most possible case for initiation of cracks in engineering structure. Cracks on the notch tip can be characterized by opening angle, tip radius, and depth of the V-notch. In this study, the effects of V-notch's opening angle on stress intensity factor and on -stress of the crack have been investigated in detail. Our calculation has been performed in a number of opening angles and various crack lengths in mode I loading using photoelasticity method. We show that as opening angle grows at constant crack's length, SIF and -stress decrease. Furthermore, as the crack's length increases, the V-notch effect diminishes and the crack behavior can be considered as a single-edge crack specimen. Finally, the obtained results were found to be in good agreement with outcome of numerical finite element analysis.

2010 ◽  
Vol 163-167 ◽  
pp. 2027-2032
Author(s):  
Dong Yan Xue ◽  
Yu Qing Liu ◽  
Qian Wang ◽  
Biao Ma

The main span is the steel truss and the side spans are the composite truss in Minpu Bridge. A 1:2.5 model is made to study the mechanical behavior of the joint segment of steel truss and composite truss. Both a model test and a numerical finite element analysis(FEA) method have been conducted. The results show that the joint segment remains in a linear elastic state under the condition. The maximum stress in the structure is less than the material allowable strength. The FEA results are in very good agreement with those of model test. This study shows that the force transformation of the joint segment is reliable and the composition details are rational. It is also expected that the results presented in this paper would be useful as references for the further research and the design of composite truss bridge and joint segment.


Author(s):  
Kazuhiro Oda ◽  
Noriko Tsutsumi ◽  
Kohei Morita ◽  
Takahiro Tsutsumi ◽  
Hou Zhong

In this study, the indentation hardness test is performed by elastic-plastic finite element (FE) analysis. In order to investigate the effect of the wear of indenter tip on the load-penetration depth curve ([Formula: see text] curve), indentation simulation is made by changing the indenter tip radius. The [Formula: see text] curve obtained by finite element method (FEM) is in good agreement with the experimental results. The calculation shows that the indentation plastic work [Formula: see text] corresponding to the area in the [Formula: see text] curve is hardly affected by the indenter tip radius.


2014 ◽  
Vol 663 ◽  
pp. 98-102 ◽  
Author(s):  
Al Emran Ismail

This paper presents the effect of eccentric cracks on the behavior of stress intensity factors (SIF) of single edge crack in bi-material plates. According to literature, it is found that most of the research conducted previously more on central single edge crack and it is well understood. However, not many research conducted on the eccentric stress intensity factor of single edge crack in bi-material plates. In order to evaluate the SIFs of eccentric edge cracks, ANSYS finite element software is used to model plain strain single edge crack in a plate subjected mode I loadings. The present SIFs are then validated with the existing central crack and it is well agreed to each others. According to the present results, it is found that mode I SIFs decreased insignificantly and mode II SIFs decreased asymptotically when the crack situated away from the central line. As expected all types of SIFs increased when crack length is increased.


2021 ◽  
Vol 1201 (1) ◽  
pp. 012053
Author(s):  
S Riise ◽  
M R Vågen ◽  
M Atteya ◽  
G Ersdal

Abstract This paper presents the experimental and numerical results for the axial capacity of cracked tubular steel members. Experimental tests of 11 columns in compression with simulated cracks of different sizes, defined as the percentage of the circumference (12%, 23.5% and 38.5%). The crack-tips were further treated by drilling a crack arresting hole. These specimens were then modelled by finite element analysis which were verified to match the experimental test. The DNVGL-RP-C208 standard was used as basis for performing the numerical finite element analysis. In addition, the capacity of the columns was calculated according to the 2004 revision of the NORSOK N-004 standard. The experimental tests indicated that the capacity in compression did not change significantly with the presence of cracks and crack arresting holes. The results from the numerical finite element analysis show a good agreement with the experimental work. However, the compressive capacity according to NORSOK N-004 shows a significant deviation to the safe side.


2021 ◽  
Vol 16 (59) ◽  
pp. 471-485
Author(s):  
Ehab Samir Mohamed Mohamed Soliman

Presence of cracks in mechanical components needs much attention, where the stress field is affected by cracks and the propagation of cracks may be occurred causing the damage. The objective of this paper is to present an investigation of crack type effect on crack severity in a finite plate. Three cases of cracked plate with three different types of cracks are assumed in this work, i.e., single edge crack, center crack and double edge crack. 2D numerical models of cases of cracked plate are established in finite element analysis (FEA), ANSYS software by adopting PLANE 183 element. Values of FEA mode I stress intensity factor SIF and Von-Mises stress at crack apex are determined for cases of cracked plate under tensile stress with different values. To identify the crack severity, the comparison of FEA results for different cracked cases is made. The comparison showed that, single edge cracked plate (SECP) has the maximum values of mode I SIF and Von-Mises stress at crack apex, i.e. the greatest crack severity is considered. Also, values of FEA Von-Mises stress at crack apex for center cracked plate (CCP) are moderate and for double edge cracked plate (DECP) are the minimum. Besides, in case of high crack lengths, it is found that, FEA results of mode I SIF in case of (CCP) are higher than those of in case of (DECP). Consequently, crack severity is considered as moderate in case of (CCP) and the minimum in case of (DECP). Empirical formulas are used to approximately estimate mode I SIF for all the case studies of cracked plate in this study and the results are compared to those of FEA. A good agreement between analytical and FEA results has been showed by this comparison.


1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.


Author(s):  
Qing Xiang Pei ◽  
B.H. Hu ◽  
C. Lu

Thermo-mechanical finite element analysis was carried out to study the deformation behavior and temperature distribution during equal channel angular pressing (ECAP). The material model used is the Johnson-Cook constitution model that can consider the multiplication effect of strain, strain rate, and temperature on the flow stress. The effects of pressing speed, pressing temperature, workpiece material and die geometry on the temperature rise and flow behavior during ECAP process were investigated. The simulated temperature rise due to deformation heating was compared with published experimental results and a good agreement was obtained. Among the various die geometries studied, the two-turn die with 0° round corner generates the highest and most uniform plastic strain in the workpiece.


2017 ◽  
Vol 17 (2) ◽  
pp. 363-378 ◽  
Author(s):  
Ayad Arab Kakei ◽  
Mainul Islam ◽  
Jinsong Leng ◽  
Jayantha A Epaarachchi

Mode I fracture analysis being employed to study delamination damage in fibre-reinforced composite structures under in-plane and out-of-plane load applications. However, due to the significantly low yield strength of the matrix material and the infinitesimal thickness of the interface matrix layer, the actual delamination process can be assumed as a partially plastic process (elasto-plastic). A simple elasto-plastic model based on the strain field in the vicinity of the crack front was developed for Mode I crack propagation. In this study, a double cantilever beam experiment has been performed to study the proposed process using a 0/90-glass woven cloth sample. A fibre Bragg grating sensor has embedded closer to the delamination to measure the strain at the vicinity of the crack front. Strain energy release rate was calculated according to ASTM D5528. The model predictions were comparable with the calculated values according to ASTM D5528. Subsequently, a finite element analysis on Abaqus was performed using ‘Cohesive Elements’ to study the proposed elasto-plastic behaviour. The finite element analysis results have shown a very good correlation with double cantilever beam experimental results, and therefore, it can be concluded that Mode I delamination process of an fibre-reinforced polymer composite can be monitored successfully using an integral approach of fibre Bragg grating sensors measurements and the prediction of a newly proposed elasto-plastic model for Mode I delamination process.


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