Residual Stress Induced by Waterjet Peening: A Finite Element Analysis

2003 ◽  
Author(s):  
Sawalee Kunaporn ◽  
Mamidala Ramulu ◽  
Michael G. Jenkins ◽  
Mohammed Hashish
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
Stress Fields ◽  
Process Conditions ◽  
Workpiece Material ◽  
Element Analysis ◽  
Compressive Stresses ◽  
Interfacial Pressure

The concept of multiple droplet impacts resulting from ultra high-pressure waterjet (UHPWJ) was used to develop a mathematical model to describe the effect of interfacial pressure on the underlying workpiece material. A non-linear elastic-plastic finite element analysis (FEA) was carried out in this study using the interfacial pressure model to predict residual compressive stresses. This three-dimensional FEA model was based on quasi-static considerations to provide prediction of both magnitude and depth of residual stress fields in a 7075-T6 aluminum alloy (A17075-T6). Results of the FEA modeling were in good agreement with experimental measurements. Effects of applied pressures on the residual stress fields are also presented and discussed as a method of estimating high-pressure waterjet induced compressive stresses under varying process conditions for peening.

Residual Stress Induced by Waterjet Peening: A Finite Element Analysis

2004 ◽  
Vol 126 (3) ◽  
pp. 333-340 ◽  
Author(s):  
S. Kunaporn ◽  
M. Ramulu ◽  
M. G. Jenkins ◽  
M. Hashish
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
Stress Fields ◽  
Process Conditions ◽  
Workpiece Material ◽  
Element Analysis ◽  
Compressive Stresses ◽  
Interfacial Pressure

The concept of multiple droplet impacts resulting from ultra high-pressure waterjet (UHPWJ) was used to develop a mathematical model to describe the effect of interfacial pressure on the underlying workpiece material. A non-linear elastic-plastic finite element analysis (FEA) was carried out in this study using the interfacial pressure model to predict residual compressive stresses. This three-dimensional FEA model was based on quasi-static considerations to provide prediction of both magnitude and depth of residual stress fields in a 7075-T6 aluminum alloy (A17075-T6). Results of the FEA modeling were in good agreement with experimental measurements. Effects of applied pressures on the residual stress fields are also presented and discussed as a method of estimating high-pressure waterjet induced compressive stresses under varying process conditions for peening.

scholarly journals Fractographical Analysis and Biomechanical Considerations of a Tooth Restored With Intracanal Fiber Post: Report of the Fracture and Importance of the Fiber Arrangements

2016 ◽  
Vol 41 (5) ◽  
pp. E149-E158 ◽  
Author(s):  
VF Wandscher ◽  
CD Bergoli ◽  
IF Limberger ◽  
TP Cenci ◽  
P Baldissara ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Fiber ◽  
Shear Stresses ◽  
Fiber Post ◽  
Element Analysis ◽  
Parallel Fibers ◽  
Tooth Structure ◽  
Anterior Teeth ◽  
Compressive Stresses

SUMMARY Objective: This article aims to present a fractographic analysis of an anterior tooth restored with a glass fiber post with parallel fiber arrangement, taking into account force vectors, finite element analysis, and scanning electron microscopy (SEM). Methods: A patient presented at the Faculty of Dentistry (Federal University of Santa Maria, Brazil) with an endodontically treated tooth (ETT), a lateral incisor that had a restorable fracture. The treatment was performed, and the fractured piece was analyzed using stereomicroscopy, SEM, and finite element analysis. Results: The absence of remaining coronal tooth structure might have been the main factor for the clinical failure. We observed different stresses actuating in an ETT restored with a fiber post as well as their relationship with the ultimate fracture. Tensile, compression, and shear stresses presented at different levels inside the restored tooth. Tensile and compressive stresses acted together and were at a maximum in the outer portions and a minimum in the inner portions. In contrast, shear stresses acted concomitantly with tensile and compressive stresses. Shear was higher in the inner portions (center of the post), and lower in the outer portions. This was confirmed by finite element analysis. The SEM analysis showed tensile and compression areas in the fiber post (exposed fibers=tensile areas=lingual surface; nonexposed fibers=compression areas=buccal surface) and shear areas inside the post (scallops and hackle lines). Stereomicroscopic analysis showed brown stains in the crown/root interface, indicating the presence of microleakage (tensile area=lingual surface). Conclusion: We concluded that glass fiber posts with parallel fibers (0°), when restoring anterior teeth, present a greater fracture potential by shear stress because parallel fibers are not mechanically resistant to support oblique occlusal loads. Factors such as the presence of remaining coronal tooth structure and occlusal stability assist in the biomechanical equilibrium of stresses that act upon anterior teeth.

Finite Element Analysis of the Rolling Contact Fatigue Life of Railcar Wheels

2008 ◽  
Vol 575-578 ◽  
pp. 1461-1466
Author(s):  
Byeong Choon Goo ◽  
Jung Won Seo
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Element Analysis ◽  
Railway Vehicles ◽  
Contact Fatigue Life

Railcar wheels and axles belong to the most critical components in railway vehicles. The service conditions of railway vehicles have been more severe in recent years due to speed-up. Therefore, a more precise evaluation of railcar wheel life and safety has been requested. Wheel/rail contact fatigue and thermal cracks due to braking are two major mechanisms of the railcar wheel failure. One of the main sources influencing on the contact zone failure is residual stress. The residual stress in wheels formed during heat treatment in manufacturing changes in the process of braking. Thus the fatigue life of railcar wheels should be estimated by considering both thermal stress and rolling contact. Also, the effect of residual stress variation due to manufacturing process and braking process should be included in simulating contact fatigue behavior. In this paper, an evaluation procedure for the contact fatigue life of railcar wheels considering the effects of residual stresses due to heat treatment, braking and repeated contact load is proposed. And the cyclic stressstrain history for fatigue analysis is simulated by finite element analysis for the moving contact load.

Three-Dimensional Finite Element Analysis of Residual Stress in Arteries

2004 ◽  
Vol 32 (2) ◽  
pp. 257-263 ◽  
Author(s):  
M. L. Raghavan ◽  
S. Trivedi ◽  
A. Nagaraj ◽  
D. D. McPherson ◽  
K. B. Chandran
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

CAD/CAE on the Mould Plates of Vertical Type High-Pressure Grouting Machine

2012 ◽  
Vol 538-541 ◽  
pp. 2681-2684
Author(s):  
Zhi Cheng Huang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
3D Model ◽  
Stress And Strain ◽  
Analysis Software ◽  
Element Analysis ◽  
Pressure Grouting ◽  
Object Of Study

Took a type of ceramics for daily use vertical type high pressure grouting machine as the object of study, study the stress and strain of its upper and lower mould plates. Established their 3D model by CAD software Pro-E, and then import them into finite element analysis software to analysis the value and distribution of the stress and strain. The analysis results can provide some reference for design, and have some engineering and practical value.

Eulerian Finite Element Analysis of 3D Machining

1999 ◽  
Author(s):  
V. Madhavan ◽  
L. Olovsson ◽  
S. C. Swargam ◽  
R. Agarwal
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
End Milling ◽  
Rake Angle ◽  
Workpiece Material ◽  
Element Analysis ◽  
Flow Angle ◽  
Chip Flow ◽  
Comparison Of The Results ◽  
Side Flow

Abstract We describe here the development and testing of a capability for finite element simulation of practical machining operations such as turning and milling, using 3D multi-material, explicit dynamic, Eulerian finite element analysis. In these simulations the workpiece material and the air surrounding it are modeled using Eulerian finite elements and the flow of the workpiece material into the air as a result of the action of the Lagrangian tool can be freely tracked. Tension tests and Taylor impact tests are simulated using the traditional Lagrangian approach as well as the Eulerian approach. Comparison of the results is used to understand the factors affecting the solution accuracy. Simulations of orthogonal machining using this technique show that the side flow of the chip is simulated realistically. Simulations of oblique machining with various rake and inclination angles confirm that the chip flow angle is independent of the rake angle. Inertial effects cause the chip flow angle to differ from the inclination angle as the weight of the chip increases. Simulations of turning and end milling show that chip formation and flow can be simulated ab-initio. The simulation capability described here can provide accurate results for various outputs of interest and is also computationally efficient, allowing a typical analysis to be completed within a day.

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