End Fitting Effect on Tensile Armor Stress Evaluation in Bent Flexible Pipe

2014 ◽  
Author(s):  
Linfa Zhu ◽  
Zhimin Tan
Keyword(s):  
Axial Stress ◽  
Local Stress ◽  
Element Model ◽  
Analysis Model ◽  
Flexible Pipe ◽  
Stress Evaluation ◽  
3D Finite Element ◽  
Closed Form Solutions ◽  
The Relationship ◽  
Pipe Bending

The stress evaluation of tensile armor layer in bent unbonded flexible pipe due to end fitting termination is investigated. A preliminary mathematical stress analysis model which accounts for the boundary condition at the end fitting interface is developed. Two shifting parameters are introduced to correct the friction field acting on the tensile wires. Closed form solutions are obtained for the modified friction force, axial stress and displacement. The validity of this model is investigated through a comparison with results obtained using a 3D finite element model. The relationship between the shifting parameters and the initial hoop position of wires is discussed. Studies of local stress elevation on wires with different initial hoop positions are conducted. The results show that end fitting effect could causes a significant stress elevation in a large amount of tensile wires if heavy pipe bending is permitted at the end fitting vicinity.

Self-tensioning Support Post Design to Control Residual Stress in MEMS Fixed-Fixed Beams

2014 ◽  
Vol 1659 ◽  
pp. 55-61
Author(s):  
Ryan M. Pocratsky ◽  
Maarten P. de Boer
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Model ◽  
Analytical Model ◽  
Local Stress ◽  
Element Model ◽  
3D Finite Element ◽  
3D Finite Element Model ◽  
Fixed Beam ◽  
Good Agreement

ABSTRACTFixed-fixed beams are ubiquitous MEMS structures that are integral components for sensors and actuation mechanisms. However, residual stress inherent in surface micromachining can affect the mechanical behavior of fixed-fixed structures, and even can cause buckling. A self-tensioning support post design that utilizes the compressive residual stress of trapped sacrificial oxide to control the stress state passively and locally in a fixed-fixed beam is proposed and detailed. The thickness and length of the trapped oxide affects the amount of stress in the beam. With this design, compression can be reduced or even converted into tension. An analytical model and a 3D finite element model are presented. The analytical model shows relatively good agreement with a 3D finite element model, indicating that it can be used for design purposes. A series of fixed-fixed beams were fabricated to demonstrate that the tensioning support post causes a reduction in buckling amplitude, even pulling the beam into tension. Phase shifting interferometry deflection measurements were used to confirm the trends observed from the models. Controlling residual stress allows longer fixed-fixed beams to be fabricated without buckling, which can improve the performance range of sensors. This technique can also enable local stress control, which is important for sensors.

Influence of Suspension Length on the Mechanical Response of Submarine Flexible Pipe under Internal Pressure and Transverse Load

2013 ◽  
Vol 671-674 ◽  
pp. 884-887
Author(s):  
Fan Gu ◽  
Hui Xin Wang ◽  
Dan Wang ◽  
Jia Quan Sun
Keyword(s):  
Internal Pressure ◽  
Mechanical Response ◽  
Axial Stress ◽  
Steel Wire ◽  
Element Model ◽  
Transverse Load ◽  
Submarine Pipeline ◽  
Flexible Pipe ◽  
Actual Structure ◽  
Rubber Layer

According to the actual structure of submarine flexible pipe, considering the combined effect of internal pressure and transverse load by wave-current flow that is based on 50 year return period wave statistics data of Cheng Dao sea area, ANSYS finite element model of flexible pipe is established. The influence of internal pressure and suspension length on the axial stress of steel wire reinforcement layer and the Mises stress of rubber layer was analyzed. Comparatively, suspension is the main cause for the failure of steel submarine pipeline, but could hardly lead to the failure of submarine flexible pipe, which shows that flexible pipe is stronger applicable for submarine pipeline.

Static analysis model of a non-pneumatic tire with elastic spokes contacting with rigid ground

2021 ◽  
pp. 095440702110483
Author(s):  
Chen Liang ◽  
Hao Liu ◽  
Hoda Mousavi ◽  
Kun Chen ◽  
Bentil Asafo-Duho ◽  
...  
Keyword(s):  
Shear Band ◽  
Element Model ◽  
Static Deformation ◽  
Analysis Model ◽  
Computationally Efficient ◽  
Governing Equations ◽  
Efficient Tool ◽  
Pneumatic Tire ◽  
The Relationship ◽  
Quantities Of Interest

An analytical model of a non-pneumatic tire is proposed to study the static deformation responses of a non-pneumatic tire in contact with a rigid ground. The tire consists of a shear band which is formed by an annular beam, and elastic spokes that connect the shear band to the rigid hub of the tire. The shear band is modeled using a Timoshenko beam. The spokes are modeled by linear springs, which are distributed evenly in circumferential direction. Governing equations of the model were derived using a theoretical analysis. The shear band static deformation was obtained based on the discussion of the relationship between spoke stiffness and the parameters of the shear band. A finite element model was developed to verify the accuracy of the model. As a part of the results from this study, a parametric analysis of quantities of interest for the tire is presented, which can be used in improving the optimal design of non-pneumatic tires. This scheme offers a holonomic solution for the complicated differential equations and gives a computationally efficient tool for rapid analyzing and designing such systems.

Analysis on the Influence of Dowel Bar at Joints on Load Stress of Pavement Slab in the Pumping Area

2011 ◽  
Vol 243-249 ◽  
pp. 4075-4079
Author(s):  
Bin Yang ◽  
Chung Tong Cheng ◽  
Li Fang Huang
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Element Model ◽  
Concrete Pavement ◽  
Slab Thickness ◽  
Void Size ◽  
3D Finite Element ◽  
Nonlinear Growth ◽  
Dowel Bar ◽  
The Relationship

A 3D finite element model is used to investigate the state of load stress developed in concrete pavement with dowel bar under the effect of typical pavement damages of pumping area of slab corner and pumping area of transverse joints edge. The results indicate that slab corner stress tends to decrease with the increase of slab thickness and possesses a nonlinear growth as pumping area increases; when the pumping area of slab corner is less than 1.5m×1.5m, the maximum pavement slab tensile stress is less than or close to the load stress in critical loading position. Stress in transverse joints edge also grows in a nonlinear tendency and axle load also grows gradually with the expansion of pumping area, of which the slope of the curve in the relationship between stress and void size is much greater. Whether it is a pumping area of slab corner or pumping area of transverse joints edge, pavement slab deformation and stress are significantly reduced after setting the dowel bar. Therefore, dowel bar can improve the stress state of concrete pavement obviously.

Effect of Material Plasticity and Metallic Layer Profiles on the Crushing Resistance of Flexible Pipes

2013 ◽  
Author(s):  
Marcel Sato ◽  
Rafael L. Tanaka ◽  
Elson L. Albuquerque ◽  
Rafael G. Morini ◽  
Carlos A. F. Godinho
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Experimental Comparison ◽  
Squeezing Effect ◽  
Flexible Pipe ◽  
3D Finite Element ◽  
Typical Situation ◽  
Flexible Pipes ◽  
Radial Strength ◽  
Polymeric Layer

This paper presents a numerical 3D finite element model to simulate a flexible pipe under crushing-traction condition, which is a typical situation found during its laying operation. This model considers the geometry of some layers from the flexible pipe, responsible of providing the most contribution to its radial strength (e.g., interlocked carcass, internal polymeric layer, pressure armor, and external polymeric layer) and geometry of laying system shoes. It also considers the flexible pipe initial ovalization and the squeezing effect due to the tensile armor layers under traction. A numerical-experimental comparison is presented, in order to show the model validity.

3D Finite Element Simulation for Turning of Hardened 45 Steel

2019 ◽  
Vol 13 (2) ◽  
pp. 181-188
Author(s):  
Meng Liu ◽  
Guohe Li ◽  
Xueli Zhao ◽  
Xiaole Qi ◽  
Shanshan Zhao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cutting Force ◽  
Finite Element Simulation ◽  
Orthogonal Experiment ◽  
Element Model ◽  
3D Finite Element ◽  
Element Simulation ◽  
Metal Machining ◽  
Single Factor Experiment

Background: Finite element simulation has become an important method for the mechanism research of metal machining in recent years. Objective: To study the cutting mechanism of hardened 45 steel (45HRC), and improve the processing efficiency and quality. Methods: A 3D oblique finite element model of traditional turning of hardened 45 steel based on ABAQUS was established in this paper. The feasibility of the finite element model was verified by experiment, and the influence of cutting parameters on cutting force was predicted by single factor experiment and orthogonal experiment based on simulation. Finally, the empirical formula of cutting force was fitted by MATLAB. Besides, a lot of patents on 3D finite element simulation for metal machining were studied. Results: The results show that the 3D oblique finite element model can predict three direction cutting force, the 3D chip shape, and other variables of metal machining and the prediction errors of three direction cutting force are 5%, 9.02%, and 8.56%. The results of single factor experiment and orthogonal experiment are in good agreement with similar research, which shows that the model can meet the needs for engineering application. Besides, the empirical formula and the prediction results of cutting force are helpful for the parameters optimization and tool design. Conclusion: A 3D oblique finite element model of traditional turning of hardened 45 steel is established, based on ABAQUS, and the validation is carried out by comparing with experiment.

scholarly journals Influential Path of Social Risk Factors toward Suicidal Behavior—Evidence from Chinese Sina Weibo Users 2013–2018

2021 ◽  
Vol 18 (5) ◽  
pp. 2604
Author(s):  
Yujin Han ◽  
He Li ◽  
Yunyu Xiao ◽  
Ang Li ◽  
Tingshao Zhu
Keyword(s):  
Risk Factors ◽  
Path Analysis ◽  
Suicide Prevention ◽  
Suicidal Behavior ◽  
Empirical Support ◽  
National Bureau ◽  
Social Risk ◽  
Analysis Model ◽  
The Relationship ◽  
Path Analysis Model

(1) Purpose: The purpose of this study was to determine suicidal risk factors, the relationship and the underlying mechanism between social variables and suicidal behavior. We hope to provide empirical support for the future suicide prevention of social media users at the social level. (2) Methods: The path analysis model with psychache as the mediate variable was constructed to analyze the relationship between suicidal behavior and selected social macro variables. The data for our research was taken from the Chinese Suicide Dictionary, Moral Foundation Dictionary, Cultural Value Dictionary and National Bureau of Statistics. (3) Results: The path analysis model was an adequate representation of the data. With the mediator psychache, higher authority vice, individualism, and disposable income of residents significantly predicted less suicidal behavior. Purity vice, collectivism, and proportion of the primary industry had positive significant effect on suicidal behavior via the mediator psychache. The coefficients of harm vice, fairness vice, ingroup vice, public transport and car for every 10,000 people, urban population density, gross domestic product (GDP), urban registered unemployment rate, and crude divorce rate were not significant. Furthermore, we applied the model to three major economic development belts in China. The model’s result meant different economic zones had no influence on the model designed in our study. (4) Conclusions: Our evidence informs population-based suicide prevention policymakers that incorporating some social factors like authority vice, individualism, etc. can help prevent suicidal ideation in China.

scholarly journals 3D finite element model of dynamic material behaviors for multilayer ultrasonic metal welding

2021 ◽  
Vol 62 ◽  
pp. 302-312
Author(s):  
Ninggang Shen ◽  
Avik Samanta ◽  
Wayne W. Cai ◽  
Teresa Rinker ◽  
Blair Carlson ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
3D Finite Element ◽  
Ultrasonic Metal Welding ◽  
3D Finite Element Model ◽  
Material Behaviors ◽  
Metal Welding

scholarly journals A Novel, Improved Equivalent Circuit Model for Double-Sided Linear Induction Motor

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1644
Author(s):  
Qian Zhang ◽  
Huijuan Liu ◽  
Tengfei Song ◽  
Zhenyang Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Equivalent Circuit ◽  
Skin Effect ◽  
Equivalent Circuit Model ◽  
Element Model ◽  
Circuit Model ◽  
End Effects ◽  
3D Finite Element ◽  
Linear Induction

A novel, improved equivalent circuit model of double-sided linear induction motors (DLIMs) is proposed, which takes the skin effect and the nonzero leakage reactance of the secondary, longitudinal, and transverse end effects into consideration. Firstly, the traditional equivalent circuit with longitudinal and transverse end effects are briefly reviewed. Additionally, the correction coefficients for longitudinal and transverse end effects derived by one-dimensional analysis models are given. Secondly, correction factors for skin effect, which reflects the inhomogeneous air gap magnetic field vertically, and the secondary leakage reactance are derived by the quasi-two-dimensional analysis model. Then, the proposed equivalent circuit is presented, and the excitation reactance and secondary resistance are modified by the correction coefficients derived from the three analytical models. Finally, a three-dimensional (3D) finite element model is used to verify the proposed equivalent circuit model under varying air gap width and frequency, and the results are also compared with that of the traditional equivalent circuit models. The calculated thrust characteristics by the proposed equivalent circuit and 3D finite element model are experimentally validated under a constant voltage–frequency drive.

scholarly journals CAD-Based 3D-FE Modelling of AISI-D3 Turning with Ceramic Tooling

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Panagiotis Kyratsis ◽  
Anastasios Tzotzis ◽  
Angelos Markopoulos ◽  
Nikolaos Tapoglou
Keyword(s):  
Statistical Model ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Fe Model ◽  
Fe Modelling ◽  
3D Finite Element ◽  
Force Components ◽  
Four Levels ◽  
The Relationship ◽  
Strong Agreement

In this study, the development of a 3D Finite Element (FE) model for the turning of AISI-D3 with ceramic tooling is presented, with respect to four levels of cutting speed, feed, and depth of cut. The Taguchi method was employed in order to create the orthogonal array according to the variables involved in the study, reducing this way the number of the required simulation runs. Moreover, the possibility of developing a prediction model based on well-established statistical tools such as the Response Surface Methodology (RSM) and the Analysis of Variance (ANOVA) was examined, in order to further investigate the relationship between the cutting speed, feed, and depth of cut, as well as their influence on the produced force components. The findings of this study point out an increased correlation between the experimental results and the simulated ones, with a relative error below 10% for most tests. Similarly, the values derived from the developed statistical model indicate a strong agreement with the equivalent numerical values due to the verified adequacy of the statistical model.

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