The Stress Analysis for the Trenchless Pipeline Rehabilitation

Author(s):  
Kuang-Chyi Lee ◽  
Rong-Yuan Jou ◽  
Hsin Her Yu ◽  
Yuan-Cheng Liang ◽  
Chien-Chang Lin

Most of the pipelines will get aging year after year and then they will need to be rehabilitated. Because of the heavy traffic on the ground or the congested pipelines under the ground, the replacement of old pipes will be very difficult in the cities. The dig-free (trenchless) method is a revolutionary pipelining method which uses air pressure, hydraulic pressure or mechanical drag force to pull the flexible piping plastic sheet into the old pipe. This research proposes a stress analysis for trenchless pipeline method by the finite element model with CATIA. The material of piping sheet is combined of two different types of epoxy with the anionic harder. We do the stress analysis of the trenchless rehabilitated pipelines to decide the optimal thickness of flexible piping plastic sheet and whether the material is available or not by finite element method.

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.


Author(s):  
J. Poirier ◽  
P. Radziszewski

The natural frequencies of circular saws limit the operating speeds of the saws. Current industry methods of increasing natural frequency include pretensioning, where plastic deformation is induced into the saw. To better model the saw, the finite element model is compared to current software for steel saws; C-SAW, a software program that calculates frequencies for stiffened circular saws. Using C-SAW and the finite element method the results are compared and the finite element method is validated for steel saws.


2014 ◽  
Vol 551 ◽  
pp. 444-447
Author(s):  
Sheng Lin ◽  
Xi Kong ◽  
Chun Wang

Based on the method of Freedom and Constraint Topology (FACT), a compliant mechanism with 3 degrees of freedom is designed. The 3 DOF are one movement and two rotations, which belongs to Case 3, Type 2. The whole stiffness matrix of the compliant mechanism is obtained. The finite element model is established for statics analysis. The results of theory analysis and finite element method are closed.


2014 ◽  
Vol 472 ◽  
pp. 56-61
Author(s):  
Yuan Chao He ◽  
Wen Lin Chen ◽  
Shi Wei Sun ◽  
Li Na Hao

Based on modal strain energy method, the paper discusses viscoelastic free layer damping sheet, establishes the finite element model of it and obtains the natural frequencies and loss factor. Then the paper calculates the loss factor of viscoelastic free layer damping structure with engineering empirical formula, and compares the result with that obtained by finite element method. By comparing the two results, it indicates that the finite element method is effective in analyzing this kind of problems.


2012 ◽  
Vol 487 ◽  
pp. 879-883
Author(s):  
Jiang Wei Wu

With the port crane getting bigger and heavier, and also moving much faster than before, the thermal effect in wheel and rail during the brake process can be a reason of the failure of port crane. In this paper, the thermal effect during the brake process of port crane is studied using the finite element method. Based on the finite element model, the ANSYS10.0 finite element software is used. The thermal effects under different coefficients are discussed. Three different slide speed of wheel, two different loads of crane, and three different frictional coefficients are applied. The importance of the different coefficients is obtained from the numerical results.


2011 ◽  
Vol 101-102 ◽  
pp. 1002-1005 ◽  
Author(s):  
Jing Zhao ◽  
Li Qun Lu

The process of multi-wedge cross wedge rolling is an advanced precision technology for forming long shaft parts such as automobile semi-axes. Three-dimensional solid model and the finite element model of semi-axes on automobile and dies of its cross wedge rolling were established. The process of cross wedge rolling was simulated according to the actual dimension of semi-axes on automobile utilizing the finite element method (FEM)software ANSYS/LS-DYNA. The required force parameters for designing semi-axes mill are determined. The appropriate roller width was determined according to the length and diameter of semi-axes on automobile. The results have provided the basis for the design of specific structure of automobile semi-axes cross wedge rolling mill.


2017 ◽  
Vol 11 (2) ◽  
pp. 116-120 ◽  
Author(s):  
Jozef Bocko ◽  
Pavol Lengvarský

AbstractThe paper deals with application of the finite element method in modelling and simulation of nanostructures. The finite element model is based on beam elements with stiffness properties gained from the quantum mechanics and nonlinear spring elements with force-displacement relation are gained from Morse potential. Several basic mechanical properties of structures are computed by homogenization of nanostructure, e.g. Young's modulus, Poisson's ratio. The problems connecting with geometrical parameters of nanostructures are considered and their influences to resulting homogenized quantities are mentioned.


Author(s):  
Andrew Melro ◽  
Kefu Liu

This paper explores the applicability of using the multiphysics finite element method to model a piezoelectric energy harvester. The piezoelectric energy harvester under consideration consists of a stainless-steel cantilever beam attached by a piezoelectric ceramic patch. Two configurations are considered: one without a proof mass and one with a proof mass. Comsol Multiphysics software is used to simultaneously model three physics: the solid mechanics, the electrostatics, and the electrical circuit physics. Several key relationships are investigated to predict the behaviours of the piezoelectric energy harvester. The effects of the electrical load resistance and a proof mass on the performance of a piezoelectric energy harvester are evaluated. Experimental testing is conducted to validate the results found by the finite element model. Overall, the results from the finite element model closely match those from the experimental testing. It is found that increasing the load resistance of the piezoelectric energy harvester causes an increase in voltage across the load resistor, and matching the impedance yields the maximum power output. Increasing the proof mass reduces the fundamental frequency that results in an increase of the displacement transmissibility and the impedance matched resistance. The study shows that the multiphysics finite element method is effective to model piezoelectric energy harvesters.


2014 ◽  
Vol 623 ◽  
pp. 34-40
Author(s):  
Li Na Song ◽  
Jun Shao ◽  
De Quan Feng ◽  
Wei Fan

With finite element method, the numerical model of the E-type diaphragm was built in this paper. Based on the model, we got the shear strain law of the E-type diaphragm surface under uniform pressure. Taking it as elastic element and the FBG as sensing element, we made a FBG pressure sensor and obtained the experiment result. The result fit well with finite element simulation value. It shows that the finite element model in the paper is reasonable and effective. The model can be used to design and optimize the sensor.


2014 ◽  
Vol 697 ◽  
pp. 173-176
Author(s):  
Hao Zou ◽  
Ming Zhang ◽  
Jia Jun Ren

In this paper, authors made contrast with the three finite element methods in analysis accuracy and usability .Those are all based on the structural analysis of mining excavator arm. The first fem is using UG solid modeling capabilities to create model .The finite element model is generated by UG_ANSYS, including setting the loads of material properties and boundary conditions ,also loading work. The process is called preprocessing completely .Then export a“. inp” file,after that, imported that file directly into ANSYS software for solving. The second one is to import solid mode created in UG into ANSYS software directly ,then take pretreatment and solution accordingly.The last one is using UG modeling and UG NX NASTRAN (the finite element analysis function) for structure analysis. It is concluded that using UG completely pretreatment of ANSYS analysis method and UG NX NASTRAN method feel more convenient to operate it with the high analyze accuracy,with the two methods , designers can modify mining mechanical arm weak positions more easily.In turns,they can improve the designing level of physical prototyping.


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