scholarly journals Stress Concentration Resulting from Irregular Shape of Explosively Cladded Materials Connections - Fem Simulation

2014 ◽  
Vol 8 (2) ◽  
pp. 103-106 ◽  
Author(s):  
Andrzej Kurek ◽  
Adam Niesłony ◽  
Marta Kurek
Keyword(s):  
Numerical Analysis ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Fem Simulation ◽  
Interface Zone ◽  
Joint Zone ◽  
Explosive Cladding ◽  
Constituent Material ◽  
Actual Profile ◽  
Maximum Stresses

Abstract The paper contains a numerical analysis of interface zone steel-titanium bimetal obtained by explosive cladding method. Due to the waviness of the zone, and various properties of the constituent material of the materials type contain structural notch. Therefore it is important inter alia in terms of presentation of the results of fatigue are the maximum stresses that occur just in the area of the zone. In the paper the stress concentration factor and the proposed method of modelling the joint zone of a sinusoidal profile, characterized by the same coefficient of stress concentration at the actual profile.

Experimental and Numerical Studies of the Stress Concentration Factor for Tubular KK-Joints under Axial Loads

2011 ◽  
Vol 314-316 ◽  
pp. 972-978
Author(s):  
Yong Tao Zhang ◽  
Shu Cheng Jin ◽  
Yan Hua Yang
Keyword(s):  
Numerical Analysis ◽  
Stress Concentration ◽  
Model Test ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Analysis Method ◽  
Axial Loads ◽  
Numerical Studies ◽  
Element Simulation ◽  
Numerical Simulation Methods

This paper reports on experimental test and numerical simulation methods that investigate the stress concentration factor and node deformation performance parameters for tubular KK-joints. The numerical analysis can give reference for design schemes of model test, and the bearing characteristics are studied by the model test. Moreover, by comparing the experimental analysis and the finite element simulation results, we discuss the accuracy of numerical analysis method in analyzing the tubular joints stress concentration factor. These can provide a useful reference for the engineering design.

Experimental and Numerical Investigations on Unstiffened Tubular T-Joints of Offshore Platforms

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
T. S. Thandavamoorthy
Keyword(s):  
Numerical Modeling ◽  
Numerical Analysis ◽  
Stress Concentration ◽  
Ultimate Strength ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Shear Failure ◽  
Failure Pattern ◽  
T Joints ◽  
Numerical Investigations

This paper presents the failure pattern, the ultimate strength, and the stress concentration factor of unstiffened T-joints obtained from experimental and numerical investigations conducted on them under axial brace compression loading. The numerical modeling was performed on the whole joint using ANSYS software package. This modeling has predicted the ultimate strength accurately when compared with that of the conventional modeling of only a portion of the joint. The nominal diameter and thickness of the chord of the unstiffened T-joints were 324 mm and 12 mm, respectively, and the corresponding values of the brace were 219 mm and 8 mm, respectively. The T-joint was approximately one-fourth the size of the largest joints in the platforms built in a shallow water depth of 80 m in the Bombay High field. The bending of the whole chord member combined with punching shear failure due to its ovalization was observed to be the predominant behavior of the unstiffened joint. The numerical analysis has simulated the behavior of the joint as was observed in the experiment and has also helped establish its correct failure pattern. It was also observed in these investigations that the unstiffened joint was stiffer in ovalization mode than in flexural deflection. The results obtained from the numerical modeling were observed, in general, to be in good agreement with that obtained from the testing. The stress concentration factor predicted by the numerical analysis is in close agreement with that measured in the experiment as well as that computed using well established parametric equations.

Stress-Concentration Factors for a Countersunk Hole in a Flat Bar in Tension and Transverse Bending

1978 ◽  
Vol 45 (4) ◽  
pp. 929-932 ◽  
Author(s):  
Y. F. Cheng
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Neutral Plane ◽  
Transverse Bending ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Maximum Stresses

A series of three-dimensional photoelastic experiments was performed to determine the maximum stresses and stress-concentration factors at countersunk holes in a flat bar in tension and transverse bending. In the tension case, the maximum stress was found at the base of the countersunk and the stress-concentration factor was approximately 33 percent higher than those found in a straight hole. In the bending case, the neutral plane was shifted toward the surface containing the straight part of the hole and the stress-concentration factor was practically the same as those found in straight holes.

scholarly journals CALCULATION OF STRESS CONCENTRATION FACTORS OF PLATES UNDER TENSION VIA COMPUTER PROGRAM DEVELOPED

2020 ◽  
Vol 29 (2) ◽  
pp. 568-583
Author(s):  
Raphael Basilio Pires Nonato
Keyword(s):  
Stress Concentration ◽  
Mathematical Modelling ◽  
Computer Program ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Elastic Range ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Maximum Stresses ◽  
Approximate Equations

Stress concentration factors (SCFs) for some set of fixed geometrical and loading cases can be obtained experimentally, analytically, and computationally. In order to accomplish this, tables and charts that relate a geometrical ratio and a specific type of loading with their correspondent stress concentration factor are commonly available. Although these resources are abundantly accessible for the most common cases, their reading and interpretation processes often imply parallax error. To overcome this difficulty, the approximate or interpolated equations may be applied. However, the application of the adequate equation in a non-structured manner can be time consuming when there are several cases to be calculated within the context of a whole design. Thus, the study of two geometrical cases of plates under tension in elastic range enabled the comparison of SCFs obtained from three sources: (a) chart reading; (b) approximate proven equations; and (c) specific computer program developed by the author. In addition, the program provides the user with the nominal and the maximum stresses for both cases. Results provided by the software were then validated through the comparison with the approximate equations applied in the mathematical modelling of the experimental charts.

scholarly journals Selection of fiber orientation around geometric discontinuities in designing against failure of GFRP laminates

2018 ◽  
Vol 188 ◽  
pp. 01010
Author(s):  
Roselita Fragoudakis
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Fiber Orientation ◽  
Failure Theory ◽  
Geometric Discontinuities ◽  
Lamination Theory ◽  
Failure Theories ◽  
Maximum Stresses ◽  
Minimum Moment ◽  
Selection Of

Determining fiber orientation around geometric discontinuities is challenging and simultaneously crucial when designing laminates against failure. This study presents an approach for selecting the fiber orientations in the vicinity of a geometric discontinuity. Maximum stresses in the discontinuity region are calculated using Classical Lamination Theory and the stress concentration factor. The use of the Tsai-Hill and Tsai-Wu failure theories estimate the minimum moment to cause failure in a lamina. Fiber orientations around the discontinuity are obtained using the Tsa-Hill failure theory.

scholarly journals A novel thread connection structure of slimehole drilling tool in ultra-deep natural gas well

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110264
Author(s):  
Zhang Ying ◽  
Lian Zhanghua ◽  
Gao Anqi ◽  
Yang Kun
Keyword(s):  
Fatigue Life ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Sensitivity Coefficient ◽  
Notch Sensitivity ◽  
Sensitivity Factor ◽  
Drilling Tool ◽  
Gas Well ◽  
Thread Connection

The thread connection’s root fillet radius of 0.038″ size is the greatest weakness of the API NC type joints and thread. During the slimehole drilling, especially in the deep and ultra-deep gas well, its stress concentration factor and notch sensitivity factor are very high A novel thread connection design (TM) of a drilling tool is proposed to decrease the fatigue failure of the slimehole drilling tool in the deep and the ultra-deep gas well in the Tarim oilfield China. The novelty in the TM thread structure is, reducing the threads per inch, extending the distance from the last engaged thread to the external shoulder of the pin and adding three threads to the conventional connection. The novel thread connection will improve the slimehole drilling tool’s anti-fatigue life due to its improved elasticity and rigidity. Furthermore, the TM can transfer the maximum stress at the connection root to the loaded surface, which can effectively lower the fatigue notch’s sensitivity coefficient. In this paper, the finite element method (FEM) is applied to carry out the detailed comparative analysis of the TM with existing thread connection NC38, TX60 and TH90. The TM has the lowest stress concentration factor and fatigue notch sensitivity coefficient, so its anti-fatigue life is the highest. In addition, TM is manufactured and is tested at Tarim oilfield in China.

Scale-Dependent Crack Modeling for Investigation the Effect of Geometrically Necessary Dislocations in Micro/Nano Grain Size of Copper

2016 ◽  
Vol 15 ◽  
pp. 1-16 ◽  
Author(s):  
Amin Zaami ◽  
Ali Shokuhfar
Keyword(s):  
Grain Size ◽  
Stress Concentration ◽  
Strain Gradient ◽  
Stress Concentration Factor ◽  
Size Effects ◽  
Crack Tip ◽  
Length Scale ◽  
State Variables ◽  
Dependent Model ◽  
Homogeneous Strain

In this study, a scale-dependent model is employed to investigate the size effects of copper on the behavior of the crack-tip. This model includes the homogeneous and non-homogeneous strain hardening based on the wavelet interpretation of size effect. Introducing additional micro/nano structural considerations together with decreasing grain size, different size effects can be obtained. As the size dependency is not taken into account in conventional plasticity, an enhanced theory which is related to the strain gradient introduces a length scale will give more realistic representations of state variables near the crack-tip. Accordingly, the contribution of geometrically necessary dislocations (GNDs) activity on strengthening and stress concentration factor is identified in the crack-tip. Finally, the affected zone which is dominated by presence of GNDs is identified

Stress Concentration of Periodic Collinear Square Holes in an Infinite Plate in Tension

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Changqing Miao ◽  
Yintao Wei ◽  
Xiangqiao Yan
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Infinite Plate ◽  
Numerical Approach ◽  
Numerical Examples ◽  
Calculated Stress ◽  
Bueckner’S Principle

A numerical approach for the stress concentration of periodic collinear holes in an infinite plate in tension is presented. It involves the fictitious stress method and a generalization of Bueckner's principle. Numerical examples are concluded to show that the numerical approach is very efficient and accurate for analyzing the stress concentration of periodic collinear holes in an infinite plate in tension. The stress concentration of periodic collinear square holes in an infinite plate in tension is studied in detail by using the numerical approach. The calculated stress concentration factor is proven to be accurate.

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