Upheaval Creep of Rock Dumped Flexible Flowline

Author(s):  
Yang Zhengmao ◽  
Kristian Norland ◽  
Neil Brown ◽  
Daniel Karunakaran

For the protection from dropped object/fishing trawl impact, flexible flowlines are normally trenched or rock-dumped. And hence, upheaval buckling and lateral buckling may be promoted by the elevated temperatures and high pressures. Due to the unique properties of un-bonded flexible flowline, the flexible flowline may creep in the trench or rock berm when it is subjected to cyclic pressure and temperature changes due to start-up and shut-down of flowline in service. In this paper, a finite element analysis model for the global buckling and upheaval creep of flexible flowline is proposed. In this model the effect of bending stiffness hysteresis are considered in addition to the temperature and pressure changes in each start-up/ shut-down cycle. A case study of a 10″ water injection flowline is performed by using finite element analysis software package ANSYS. The nonlinear general beam section is used to simulate the specific flexible pipe behavior, nonlinear bending behavior but linear axial behavior.

2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.


Author(s):  
Constantine M. Tarawneh ◽  
Arturo A. Fuentes ◽  
Javier A. Kypuros ◽  
Lariza A. Navarro ◽  
Andrei G. Vaipan ◽  
...  

In the railroad industry, distressed bearings in service are primarily identified using wayside hot-box detectors (HBDs). Current technology has expanded the role of these detectors to monitor bearings that appear to “warm trend” relative to the average temperatures of the remainder of bearings on the train. Several bearings set-out for trending and classified as nonverified, meaning no discernible damage, revealed that a common feature was discoloration of rollers within a cone (inner race) assembly. Subsequent laboratory experiments were performed to determine a minimum temperature and environment necessary to reproduce these discolorations and concluded that the discoloration is most likely due to roller temperatures greater than 232 °C (450 °F) for periods of at least 4 h. The latter finding sparked several discussions and speculations in the railroad industry as to whether it is possible to have rollers reaching such elevated temperatures without heating the bearing cup (outer race) to a temperature significant enough to trigger the HBDs. With this motivation, and based on previous experimental and analytical work, a thermal finite element analysis (FEA) of a railroad bearing pressed onto an axle was conducted using ALGOR 20.3™. The finite element (FE) model was used to simulate different heating scenarios with the purpose of obtaining the temperatures of internal components of the bearing assembly, as well as the heat generation rates and the bearing cup surface temperature. The results showed that, even though some rollers can reach unsafe operating temperatures, the bearing cup surface temperature does not exhibit levels that would trigger HBD alarms.


2013 ◽  
Vol 690-693 ◽  
pp. 2327-2330
Author(s):  
Ming Bo Han ◽  
Li Fei Sun

By using finite element software, the paper establishes the main stand analysis model of the Ф140 pipe rolling mill and provides the model analysis of main stand in cases of full load. Verify the design of main stand fully comply with the technical requirements .In this paper, it provides the theoretical position of split casting and welding method using electric slag welding.


Author(s):  
Dinesh Shinde ◽  
Mukesh Bulsara ◽  
Jeet Patil

Brake friction lining material is the critical element of a braking system, since it provides friction resistance to the rotating drum for controlling automobiles. The present study involves wear analysis of newly developed eco-friendly non-asbestos friction lining material for automotive drum brake applications using experimental study, finite-element analysis, and microstructural investigations. Theoretical interpretation of braking force at different automobile speeds was derived using fundamentals. Specimen drum brake liner with eco-friendly material compositions was produced using an industrial hot compression molding process at one of the manufacturer. The surface wear of the liner was measured using an effective and accurate method. Furthermore, a finite-element analysis model was developed considering actual operating conditions and various components of the drum brake system. The model was elaborated for various result outcomes, including Von-Mises stresses and total deformation of components of the drum brake, and further used to estimate the surface wear of the friction lining material in terms of transverse directional deformation. Finally, microstructural analysis of the friction lining material was carried out using scanning electron microscopy and energy dispersive spectroscopy. From the results, it is seen that the developed friction lining material is wear resistant. The finite-element analysis model can be effectively utilized to study the tribological characteristics of friction lining materials.


2002 ◽  
Vol 124 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Y. B. Guo ◽  
C. R. Liu

A practical explicit 3D finite element analysis model has been developed and implemented to analyze turning hardened AISI 52100 steels using a PCBN cutting tool. The finite element analysis incorporated the thermo-elastic-plastic properties of the work material in machining. An improved friction model has been proposed to characterize tool-chip interaction with the friction coefficient and shear flow stresses determined by force calibration and material tests, respectively. A geometric model has been established to simulate a 3D turning. FEA Model predictions have reasonable accuracy for chip geometry, forces, residual stresses, and cutting temperatures. FEA model sensitivity analysis indicates that the prediction is consistent using a suitable magnitude of material failure strain for chip separation, the simulation gives reasonable results using the experimentally determined material properties, the proposed friction model is valid and the sticking region on the tool-chip interface is a dominant factor of model predictions.


2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097774
Author(s):  
Jiawei Wang ◽  
Fachao Li ◽  
Zibo Chen ◽  
Baishu Li ◽  
Jue Zhu

This paper studies the force and deformation of the connecting channel in Ningbo rail transit construction, which firstly used the mechanical shield method. Steel-concrete composite structural segments are used in the T-joint of connecting channel. The cutting part of the segments are replaced by the concrete and fiberglass instead of reinforced concrete. Basing on a variety of three-dimensional design software and ABAQUS finite element analysis software, a refined finite element analysis model of the special segments is established. By considering the influence of curved joint bolts, the force analysis of the special segments under the structural state before and after construction is performed. According to the analysis and comparison of the deformation of the segments with and without the bolts, it is concluded that the steel-concrete segments can withstand the pressure of the soil before and after the construction. Suggestions for the safety of the design and construction of the segments are put forward.


Spine ◽  
2020 ◽  
Vol 45 (16) ◽  
pp. E978-E988
Author(s):  
Deepak Gupta ◽  
Mohd Zubair ◽  
Sanjeev Lalwani ◽  
Shiva Gamanagatti ◽  
Tara Sankar Roy ◽  
...  

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