Simulation on polytropic process of air springs

2016 ◽  
Vol 33 (7) ◽  
pp. 1957-1968 ◽  
Author(s):  
Xuebing Li ◽  
Yintao Wei ◽  
Yuan He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Design Methodology ◽  
Air Spring ◽  
Content Type ◽  
Polytropic Process ◽  
Pneumatic Structures ◽  
Element Method

Purpose The purpose of this paper is to propose a method to simulate the polytropic process of air springs. Design/methodology/approach An iterative finite element method (FEM) is proposed. Findings The proposed method is reliable and effective in solving the polytropic process of air springs. Originality/value This work would be helpful for understanding the simulation of pneumatic structures, and the proposed modified FEM would be useful for improving the simulation of the mechanical behavior of an air spring.

Numerical simulation of Plateau’s problem of minimal surfaces using nonvariational finite element method

2016 ◽  
Vol 33 (5) ◽  
pp. 1490-1507 ◽  
Author(s):  
Garima Mishra ◽  
Manoj Kumar
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Minimal Surfaces ◽  
Design Methodology ◽  
Engineering Application ◽  
Content Type ◽  
Plateau’S Problem ◽  
Plateau's Problem ◽  
Element Method

Purpose – Numerical solution of Plateau’s problem of minimal surface using non-variational finite element method. The paper aims to discuss this issue. Design/methodology/approach – An efficient algorithm is proposed for the computation of minimal surfaces and numerical results are presented. Findings – The solutions obtained here are examined for different cases of non-linearity and are found sufficiently accurate. Originality/value – The manuscript provide the non-variational solution for Plateau’s problem. Thus it has a good value in engineering application.

A finite element model for estimating time-dependent reliability of a corroded pipeline elbow

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mourad Nahal ◽  
Rabia Khelif
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Mechanical Behavior ◽  
Time Dependent ◽  
Behavior Model ◽  
The Finite Element Method ◽  
Content Type ◽  
Reliability Method ◽  
Element Method

PurposeThe aim of this paper is to investigate the failure probability in an irregular area in pipeline (elbow) over its lifetime. The reliability analysis is performed by using of an enhanced first-order reliability method / second-order reliability method (FORM/SORM) and Monte Carlo simulation methods: a numerical model of a corroded pipeline elbow was developed by using finite element method; also, an empirical mechanical behavior model has been proposed. A numerical case with high, moderate and low corrosion rates was conducted to calculate the deferent reliability indexes. The found results can be used in an application case for managing an irregular area in pipeline lifetime. Hence, it is necessary to ensure a rigorous inspection for this part of a pipeline to avoid human and environmental disasters.Design/methodology/approachThe present paper deals a methodology for estimating time-dependent reliability of a corroded pipeline elbow. Firstly, a numerical model of corroded elbow is proposed by using the finite element method. A mechanical behavior under the corrosion defect in time is studied, and an empirical model was also developed.FindingsThe result of this paper can be summarized as: a mechanical characterization of the material was carried out experimentally. A numerical model of a corroded pipeline elbow was developed by using the finite element method. An empirical mechanical behavior model has been developed. The reliability of a corroding pipe elbow can be significantly affected by corrosion and residual stress. A proportional relationship has been found between probability of failure and corrosion rate. The yield stress and pressure service have an important sensitivity factor.Originality/valueAiming to help Algerian gas and oil companies' decision makers, the present paper illustrates a methodology for estimating time-dependent reliability of a corroded pipeline elbow over its lifetime using numerical models by applying the finite element method. Firstly, a numerical model of a corroded pipe elbow was developed and coupled with an empirical mechanical behavior model, which is also proposed. A probabilistic is then developed to provide realistic corrosion parameters and time modeling, leading to the real impact on the lifetime of an elbow zone in pipeline. The reliability indexes and probability of failure for various corrosion rates with and without issued residual stress are computed using Monte Carlo simulation and FORM.

Parallel finite-element method using domain decomposition and Parareal for transient motor starting analysis

2019 ◽  
Vol 38 (5) ◽  
pp. 1507-1520 ◽  
Author(s):  
Yasuhito Takahashi ◽  
Koji Fujiwara ◽  
Takeshi Iwashita ◽  
Hiroshi Nakashima
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Parallel Computing ◽  
Domain Decomposition ◽  
Parallel Computation ◽  
Domain Decomposition Method ◽  
Space Time ◽  
Content Type ◽  
Parallel Performance ◽  
Element Method

Purpose This paper aims to propose a parallel-in-space-time finite-element method (FEM) for transient motor starting analyses. Although the domain decomposition method (DDM) is suitable for solving large-scale problems and the parallel-in-time (PinT) integration method such as Parareal and time domain parallel FEM (TDPFEM) is effective for problems with a large number of time steps, their parallel performances get saturated as the number of processes increases. To overcome the difficulty, the hybrid approach in which both the DDM and PinT integration methods are used is investigated in a highly parallel computing environment. Design/methodology/approach First, the parallel performances of the DDM, Parareal and TDPFEM were compared because the scalability of these methods in highly parallel computation has not been deeply discussed. Then, the combination of the DDM and Parareal was investigated as a parallel-in-space-time FEM. The effectiveness of the developed method was demonstrated in transient starting analyses of induction motors. Findings The combination of Parareal with the DDM can improve the parallel performance in the case where the parallel performance of the DDM, TDPFEM or Parareal is saturated in highly parallel computation. In the case where the number of unknowns is large and the number of available processes is limited, the use of DDM is the most effective from the standpoint of computational cost. Originality/value This paper newly develops the parallel-in-space-time FEM and demonstrates its effectiveness in nonlinear magnetoquasistatic field analyses of electric machines. This finding is significantly important because a new direction of parallel computing techniques and great potential for its further development are clarified.

Semi-analytical finite element method for simulating chemical dissolution-front instability problems in fluid-saturated porous media

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chongbin Zhao ◽  
B.E. Hobbs ◽  
Alison Ord
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Porous Media ◽  
Chemical Dissolution ◽  
Saturated Porous Media ◽  
Content Type ◽  
Front Instability ◽  
Fluid Saturated Porous Media ◽  
Dissolution Front ◽  
Element Method

PurposeThe objective of this paper is to develop a semi-analytical finite element method for solving chemical dissolution-front instability problems in fluid-saturated porous media.Design/methodology/approachThe porosity, horizontal and vertical components of the pore-fluid velocity and solute concentration are selected as four fundamental unknown variables for describing chemical dissolution-front instability problems in fluid-saturated porous media. To avoid the use of numerical integration, analytical solutions for the property matrices of a rectangular element are precisely derived in a purely mathematical manner. This means that the proposed finite element method is a kind of semi-analytical method. The column pivot element solver is used to solve the resulting finite element equations of the chemical dissolution-front instability problem.FindingsThe direct use of horizontal and vertical components of the pore-fluid velocity as fundamental unknown variables can improve the accuracy of the related numerical solution. The column pivot element solver is useful for solving the finite element equations of a chemical dissolution-front instability problem. The proposed semi-analytical finite element method can produce highly accurate numerical solutions for simulating chemical dissolution-front instability problems in fluid-saturated porous media.Originality/valueAnalytical solutions for the property matrices of a rectangular element are precisely derived for solving chemical dissolution-front instability problems in fluid-saturated porous media. The proposed semi-analytical finite element method provides a useful way for understanding the underlying dynamic mechanisms of the washing land method involved in the contaminated land remediation.

scholarly journals Analysis of Vertical Stiffness of Air Spring Based on Finite Element Method

2018 ◽  
Vol 153 ◽  
pp. 06006
Author(s):  
Jiatong Ye ◽  
Hua Huang ◽  
Chenchen He ◽  
Guangyuan Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Element Model ◽  
Simulation Method ◽  
Bench Test ◽  
Air Spring ◽  
Vertical Stiffness ◽  
Element Simulation ◽  
Element Method

In this paper, a finite element model of membrane air spring in the vehicle is established, and its vertical stiffness characteristics under a certain inflation pressure are analysed. The result of finite element simulation method is compared with the result of the air spring bench test. The accuracy and reliability of the finite element simulation method in nonlinear analysis of air spring system are verified. In addition, according to the finite element method, the influence of the installation of the air spring limit sleeve on its stiffness is verified.

Stress, strain and displacement analysis of geodetic and conventional fuselage structure for future passenger aircraft

2019 ◽  
Vol 91 (6) ◽  
pp. 814-819
Author(s):  
Zdobyslaw Jan Goraj ◽  
Mariusz Kowalski ◽  
Bartlomiej Goliszek
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Weight Reduction ◽  
Composite Structures ◽  
Lattice Structure ◽  
Small Displacement ◽  
Structure Stability ◽  
Outer Diameter ◽  
Content Type ◽  
Element Method

Purpose This paper aims to present the results of calculations that checked how the longerons and frames arrangement affects the stiffness of a conventional structure. The paper focuses only on first stage of research – analysis of small displacement. Main goal was to compare different structures under static loads. These results are also compared with the results obtained for a geodetic structure fuselage model of the same dimensions subjected to the same internal and external loads. Design/methodology/approach The finite element method analysis was carried out for a section of the fuselage with a diameter of 6.3 m and a length equal to 10 m. A conventional and lattice structure – known as geodetic – was used. Findings Finite element analyses of the fuselage model with conventional and geodetic structures showed that with comparable stiffness, the weight of the geodetic fuselage is almost 20 per cent lower than that of the conventional one. Research limitations/implications This analysis is limited to small displacements, as the linear version of finite element method was used. Research and articles planned for the future will focus on nonlinear finite element method (FEM) analysis such as buckling, structure stability and limit cycles. Practical implications The increasing maturity of composite structures manufacturing technology offers great opportunities for aircraft designers. The use of carbon fibers with advanced resin systems and application of the geodetic fuselage concept gives the opportunity to obtain advanced structures with excellent mechanical properties and low weight. Originality/value This paper presents very efficient method of assessing and comparison of the stiffness and weight of geodetic and conventional fuselage structure. Geodetic fuselage design in combination with advanced composite materials yields an additional fuselage weight reduction of approximately 10 per cent. The additional weight reduction is achieved by reducing the number of rivets needed for joining the elements. A fuselage with a geodetic structure compared to the classic fuselage with the same outer diameter has a larger inner diameter, which gives a larger usable space in the cabin. The approach applied in this paper consisting in analyzing of main parameters of geodetic structure (hoop ribs, helical ribs and angle between the helical ribs) on fuselage stiffness and weight is original.

Numerical modeling of structural capacity of corroded bolted assembly

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rachid Radouani ◽  
Mohamed Essahli ◽  
Younes Ech-Charqy
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Stress Corrosion Cracking ◽  
Design Methodology ◽  
Bolted Joint ◽  
The Finite Element Method ◽  
Content Type ◽  
Structural Capacity ◽  
Resistant Moment

PurposeValidate the resistance of bolted connections in terms of stresses, resistant moment and contact pressure.Design/methodology/approachFinite element modeling of corroded bolted joint.FindingsThe three types of corroded assemblies are resistant to the applied loads.Originality/valueThe research is original, it studies the stress corrosion cracking of a bolted assembly's end plate by the finite element method.

A MSFEM to simulate the eddy current problem in laminated iron cores in 3D

2019 ◽  
Vol 38 (5) ◽  
pp. 1667-1682 ◽  
Author(s):  
Karl Hollaus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Eddy Current ◽  
Eddy Currents ◽  
Three Dimensional ◽  
Harmonic Balance Method ◽  
Three Dimensions ◽  
Magnetic Vector Potential ◽  
Content Type ◽  
Element Method

Purpose The simulation of eddy currents in laminated iron cores by the finite element method (FEM) is of great interest in the design of electrical devices. Modeling each laminate by finite elements leads to extremely large nonlinear systems of equations impossible to solve with present computer resources reasonably. The purpose of this study is to show that the multiscale finite element method (MSFEM) overcomes this difficulty. Design/methodology/approach A new MSFEM approach for eddy currents of laminated nonlinear iron cores in three dimensions based on the magnetic vector potential is presented. How to construct the MSFEM approach in principal is shown. The MSFEM with the Biot–Savart field in the frequency domain, a higher-order approach, the time stepping method and with the harmonic balance method are introduced and studied. Findings Various simulations demonstrate the feasibility, efficiency and versatility of the new MSFEM. Originality/value The novel MSFEM solves true three-dimensional eddy current problems in laminated iron cores taking into account of the edge effect.

Dynamic tensile process of blended fabric using finite element method

2020 ◽  
Vol 32 (5) ◽  
pp. 707-724
Author(s):  
Xuzhong Su ◽  
Xinjin Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Testing ◽  
Woven Fabrics ◽  
Weft Yarn ◽  
Tensile Fracture ◽  
Content Type ◽  
Tensile Process ◽  
Simulation Results ◽  
Element Method

PurposeTensile property is one basic mechanics performance of the fabric. In general, not only the tensile values of the fabric are needed, but also the dynamic changing process under the tension is also needed. However, the dynamic tensile process cannot be included in the common testing methods by using the instruments after fabric weaving.Design/methodology/approachBy choosing the weft yarn and warp yarn in the fabric as the minimum modeling unit, 1:1 finite element model of the whole woven fabrics was built by using AutoCAD software according to the measured geometric parameters of the fabrics and mechanical parameters of yarns. Then, the fabric dynamic tensile process was simulated by using the ANSYS software. The stress–strain curve along the warp direction and shrinkage rate curve along the weft direction of the fabrics were simulated. Meanwhile, simulation results were verified by comparing to the testing results.FindingsIt is shown that there are four stages during the fabric tensile fracture process along the warp direction under the tension. The first stage is fabric elastic deformation. The second stage is fabric yield deformation, and the change rate of stress begins to slow down. The third stage is fiber breaking, and the change of stress fluctuates since the breaking time of the fibers is different. The fourth stage is fabric breaking.Originality/valueIn this paper, the dynamic tensile process of blended woven fabrics was studied by using finite element method. Although there are differences between the simulation results and experimental testing results, the overall tendency of simulation results is the same as the experimental testing results.

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