scholarly journals Numerical Study of Being Forced Leather Cap Type Pig in Straight Gas Pipeline

2016 ◽  
Vol 10 (1) ◽  
pp. 141-148
Author(s):  
Liqiong Chen ◽  
Yunyun Li ◽  
Xiaoxiao Chen ◽  
Yilan Zhan ◽  
Meijuan Dang
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Numerical Study ◽  
Geometric Model ◽  
Gas Pipeline ◽  
Average Force ◽  
Oil Pipeline ◽  
Finite Element Software ◽  
Operation Rules ◽  
The Mathematical Model

The research on pipeline pigging technology is significant for the operation and management of pipeline. Domestic and foreign scholars usually research the operation rules of pigging in oil pipeline. There are few studies about gas pipeline pigging running because of running rate. The author established the force calculating model and corresponding numerical methods of leather cap type pig in gas pipeline. The model is based on geometric model of oil pipeline pigging. Combining pigging operation parameters with records in September 2013 and February 2014 at Bei Neihuan, the thesis used mathematical method and finite element software respectively to verify the mathematical model. The mathematical results described the average force of cup. The results indicated that the reason of the breaking of the cup is the force, instead of the cup material, temperament extrinsic reasons, etc. The force is larger than the tensile strength of the cup. The results of ANSYS finite element software simulation described the force of different parts of the cup. It is found that the force exceeding of the cup anti-pull force strength in the upper and lower sides of the cup is larger. Both results showed that using the mathematical model can quickly calculate cup pigging force conditions and determine the cause of damage to the cup. It can improve the efficiency of pigging.

scholarly journals Acoustic Velocity Correcting Method for the Tilted Acoustic Tube in Testing of Pile by Ultrasonic Transmission

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yongqiang Cui ◽  
Zhitao Ma ◽  
Yachao Yang ◽  
Daifu Song
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Element ◽  
Acoustic Signal ◽  
Acoustic Velocity ◽  
Normal Value ◽  
Finite Element Software ◽  
Modified Method ◽  
The Mathematical Model ◽  
Depth Curve

The finite element software ABAQUS was used to simulate the detection of piles by ultrasonic transmission. The influence of the tilted acoustic tube on the testing results of the pile was analyzed. The results showed that, when the pile was complete, the velocity of the sound-depth curve of the received signal was inclined to one side due to the inclination of the acoustic tube and the velocity of the sound seriously deviated from the normal value; when there was a defect in the pile, the signal of the defect was not obvious due to the tilt of the acoustic tube, which was easy to miss or misjudge the defects of the pile. To solve the problem of the inclined acoustic tube, the mathematical model of the position relation of the acoustic tube was established, and the method for correcting the velocity of the sound based on the angle of the acoustic tube was derived. Numerical simulation and engineering examples were used to verify the modified method; the verification showed that the corrected acoustic signal could accurately determine the defects and their positions in the pile, and this method effectively reduced the influence of the tilted acoustic tube on the detection signal, which was beneficial to improve the accuracy of the testing for the pile.

scholarly journals Developing 1D MM of Axisymmetric Transient Quenched Chromium Steel to Determine LHP

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Abdlmanam S. A. Elmaryami ◽  
Badrul Omar
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Chromium Steel ◽  
Temperature History ◽  
Finite Element Software ◽  
Steel Bar ◽  
History Of ◽  
Quenched Steel ◽  
The Impact ◽  
The Mathematical Model

The modelling of an axisymmetric industrial quenched chromium steel bar AISI-SAE 8650H based on finite element method has been produced to investigate the impact of process history on metallurgical and material properties. Mathematical modelling of 1-dimensional line (radius) element axisymmetric model has been adopted to predict temperature history and consequently the hardness of the quenched steel bar at any point (node). The lowest hardness point (LHP) is determined. In this paper hardness in specimen points was calculated by the conversion of calculated characteristic cooling time for phase transformation t8/5 to hardness. The model can be employed as a guideline to design cooling approach to achieve desired microstructure and mechanical properties such as hardness. The developed mathematical model is converted to a computer program. This program can be used independently or incorporated into a temperature history calculator to continuously calculate and display temperature history of the industrial quenched steel bar and thereby calculate LHP. The developed program from the mathematical model has been verified and validated by comparing its hardness results with commercial finite element software results.

A Meshless Method for Solving the Mathematical Model Associated the Leakage Problem in Gas Pipeline

2014 ◽  
Vol 986-987 ◽  
pp. 1418-1421
Author(s):  
Jun Shan Li
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Partial Differential Equation ◽  
Inverse Problem ◽  
Basis Function ◽  
Meshless Method ◽  
Numerical Solutions ◽  
Basis Functions ◽  
Gas Pipeline ◽  
The Mathematical Model

In this paper, we propose a meshless method for solving the mathematical model concerning the leakage problem when the pressure is tested in the gas pipeline. The method of radial basis function (RBF) can be used for solving partial differential equation by writing the solution in the form of linear combination of radius basis functions, that is, when integrating the definite conditions, one can find the combination coefficients and then the numerical solution. The leak problem is a kind of inverse problem that is focused by many engineers or mathematical researchers. The strength of the leak can find easily by the additional conditions and the numerical solutions.

scholarly journals Finite Element Modeling of Multiscale Diffusion in Intercalated Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Antonio Greco ◽  
Alfonso Maffezzoli
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Random Distribution ◽  
Geometric Model ◽  
Fe Analysis ◽  
Morphological Features ◽  
Diffusion Behavior ◽  
Simulation Results ◽  
Diffusion Simulation

This work is aimed to study the diffusion in 3D nanocomposites obtained with stacks of lamellar nanofillers characterized by the presence of permeable galleries, by finite element (FE) analysis. To this purpose, a geometric model, based on a random distribution of noninterpenetrating stacks, with each one being made of regularly spaced lamellae, was developed. The developed model is able to account for diffusion between stacks (interstack diffusion) as well as diffusion inside stacks (intrastack diffusion). Simulation results showed that intrastack diffusion, related to flow inside galleries, can be quite relevant, particularly at high values of gallery thickness. Comparison of the simulation results with literature models shows that when intrastack diffusion is not taken into account, the diffusion behavior in intercalated nanocomposites is not well predicted. Therefore, intrastack permeability of nanofillers such as organic modified clays cannot be neglected. Such intrastack diffusivity is shown to depend on the morphological features of the nanofiller requiring the development of a proper mathematical model.

Experimental and numerical study on largely perforated steel shear plates with rectangular tube–shaped links

2020 ◽  
Vol 23 (15) ◽  
pp. 3307-3322 ◽  
Author(s):  
H Monsef Ahmadi ◽  
MR Sheidaii ◽  
H Boudaghi ◽  
G De Matteis
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Equivalent Plastic Strain ◽  
Absorption Capacity ◽  
Hysteretic Behavior ◽  
Steel Plate Shear Wall ◽  
Grid Systems ◽  
Finite Element Software ◽  
Internal Link ◽  
Rectangular Tube

Steel plate shear wall is one of the most effective dissipation systems which are commonly used in buildings. In order to improve the hysteretic behavior of shear panels, large perforation patterns may be applied, transforming the shear plate into a sort of grid systems, where plastic deformations are concentrated on specific internal link elements. This study investigates the behavior of grid systems loaded in shear where the internal links are created by cutting out internal parts, leaving rectangular tube–shaped link elements. The influence of internal link geometry on the cyclic performance of the systems is investigated experimentally. To this purpose, two specimens that varied in the width of links were fabricated and tested. The results indicate that any increase in the width of links leads to the growth of the ultimate strength, stiffness, and energy absorption capacity. Likewise, the stress distribution and fracture tendency of the tested specimens have been simulated by the finite element software (ABAQUS) and validated according to the experimental results. Based on finite element results, a suitable analytical formulation for the prediction of the shear strength at several shear deformation demands, considering the effect of thickness of the link, has been provided. Moreover, to improve the fracture tendency of the specimens, butterfly-shaped links, which varied in the middle length, were applied. The obtained results, which have been interpreted by considering the equivalent plastic strain value, prove that the shear panel behavior improves significantly when butterfly-shaped links are considered.

scholarly journals Modeling and Optimization of Bidirectional Clamping Forces in Drilling of Stacked Aluminum Alloy Plates

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2866
Author(s):  
Jintong Liu ◽  
Anan Zhao ◽  
Piao Wan ◽  
Huiyue Dong ◽  
Yunbo Bi
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Clamping Force ◽  
Practical Application ◽  
Element Simulation ◽  
Theory Of Plates ◽  
Plates And Shells ◽  
The Mathematical Model ◽  
The Relationship

Interlayer burrs formation during drilling of stacked plates is a common problem in the field of aircraft assembly. Burrs elimination requires extra deburring operations which is time-consuming and costly. An effective way to inhibit interlayer burrs is to reduce the interlayer gap by preloading clamping force. In this paper, based on the theory of plates and shells, a mathematical model of interlayer gap with bidirectional clamping forces was established. The relationship between the upper and lower clamping forces was investigated when the interlayer gap reaches zero. The optimization of the bidirectional clamping forces was performed to reduce the degree and non-uniformity of the deflections of the stacked plates. Then, the finite element simulation was conducted to verify the mathematical model. Finally, drilling experiments were carried out on 2024-T3 aluminum alloy stacked plates based on the dual-machine-based automatic drilling and riveting system. The experimental results show that the optimized bidirectional clamping forces can significantly reduce the burr heights. The work in this paper enables us to understand the effect of bidirectional clamping forces on the interlayer gap and paves the way for the practical application.

Calculations of three-dimensional viscous flow in a multiblade centrifugal fan by modelling blade forces

2003 ◽  
Vol 217 (3) ◽  
pp. 287-297 ◽  
Author(s):  
S-J Seo ◽  
K-Y Kim ◽  
S-H Kang
Keyword(s):  
Mathematical Model ◽  
Turbulent Flows ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Centrifugal Fan ◽  
Complex Flows ◽  
Flow Through ◽  
Volume Method ◽  
The Mathematical Model

A numerical study is presented for Reynolds-averaged Navier-Stokes analysis of three-dimensional turbulent flows in a multiblade centrifugal fan. Present work aims at development of a relatively simple analysis method for these complex flows. A mathematical model of impeller forces is obtained from the integral analysis of the flow through the impeller. A finite volume method for discretization of governing equations and a standard k-ɛ model as turbulence closure are employed. For the validation of the mathematical model, the computational results for velocity components, static pressure, and flow angles at the exit of the impeller were compared with experimental data. The comparisons show generally good agreement, especially at higher flow coefficients.

The Mathematical Model of Simulative Calculation for the Process of Airbag Landing

2014 ◽  
Vol 635-637 ◽  
pp. 228-232
Author(s):  
Jian He ◽  
Ji Sheng Ma ◽  
Da Lin Wu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Calculation Method ◽  
Low Cost ◽  
Analytical Analysis ◽  
Heavy Equipment ◽  
Element Simulation ◽  
The Mathematical Model

Airbag is widely used in heavy equipment dropped field with its efficient cushion performance and low cost. The calculation method used now for the process of airbag landing mainly is simulative calculation: analytical analysis and finite element simulation, but there are less systematic introduction for the mathematical model behind these methods in past papers. This paper mainly does the summary for the mathematical model of vented airbag which is usually used.

Optimal Design of Dynamic Secondary Cooling of Continuous Casting

2012 ◽  
Vol 472-475 ◽  
pp. 1907-1910
Author(s):  
Yi Wang ◽  
Xin Jian Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Element ◽  
Continuous Casting ◽  
Cooling System ◽  
Solidification Process ◽  
Element Model ◽  
Secondary Cooling ◽  
The Mathematical Model ◽  
The Finite Element Model

Numerical simulation of the secondary cooling is applied to the design of continuous casting. The mathematical model for solidification process of the strand under air-mist was established and calculated with the finite element model. The model is used to calculate the feasible operating range of the continuous casting machines. The dynamic secondary cooling system has been analyzed with consideration of the thermo mechanical principles and numerical model. The adequacy of the model has been confirmed with experimental results.

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