scholarly journals A Design Method for Rail Profiles in Switch Panel of Turnout Based on the Contact Stress Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Dilai Chen ◽  
Gang Shen ◽  
Xin Mao ◽  
Buchen Chen
Keyword(s):  
Contact Stress ◽  
Cross Sections ◽  
Design Method ◽  
Dynamic Performance ◽  
Dynamical Behavior ◽  
Contact Theory ◽  
Maximal Contact ◽  
Wheel Profile ◽  
Matching Degree ◽  
The Relationship

Contact stress between wheel and rail is believed to cause damage to the rail. The relationship between the contact stress and the radius of the rail is initially based on the Hertz contact theory. By adjusting its radius, the rail profile is designed with an objective of reducing the maximal contact stress between wheel and rail. The rail profile of turnout is parameterized by defining several control cross sections along the switch. The experiment of dynamic vehicle-turnout interaction is also carried out to investigate the effect of the improved rail profile on the dynamical behavior of the vehicle. The method is then verified through examples using rail profile with a switch width of 20 mm and LM worn-type tread at the CN60-350-1:12 turnout. The results show that the designed rail has a higher matching degree with the wheel profile. It can reduce the contact stress, improve the wheel-rail contact state, and prolong the service life of the rail without deteriorating the dynamic performance of the vehicle passing through the turnout.

The Stability Analysis of Reinforced Earth Retaining Wall System and the Study of its Reinforcement Optimization

2011 ◽  
Vol 90-93 ◽  
pp. 2389-2392
Author(s):  
Hai Yan Ju ◽  
Gui Qing Gao ◽  
Jian Hua Li ◽  
Jiang Qian Zhao ◽  
Zhang Ming Li
Keyword(s):  
Cross Sections ◽  
Design Method ◽  
Retaining Wall ◽  
Physical Behavior ◽  
Reinforced Earth ◽  
Slope Treatment ◽  
The Stability ◽  
Relationship Of ◽  
The Relationship ◽  
System Program

Because the relationship is not considered between physical behavior and cross sections of bars, the conventional reinforced earth retaining wall design based on constant value would lead to some limitations: the haul-resistant coefficient of the top wall is not enough, but it goes beyond at the bottom of retaining wall. In the paper, considering the SARMA method, based on computing formula of traditional slope stability, the detailed programme is realized by the language of FORTRAN, it can make up deficiency that lies in the tradition reinforced earth retaining wall by considering the relationship of physical behavior and cross sections, lengths and layers of bars. Finally, the system program has been applied to a slope treatment project in Guangzhou. Compared with the design method of traditional regulations, it is demonstrated that the optimum length required is obtained, the cross section and length of bars are fully used, and the design is simplified.

The Design Method of Major Parameters for Built-Up Columns

2014 ◽  
Vol 915-916 ◽  
pp. 264-272
Author(s):  
Gui Yu Lin ◽  
Yan Feng Luo ◽  
Ting Na Sun ◽  
Kui Xian Li
Keyword(s):  
Cross Sections ◽  
Critical Stress ◽  
Design Method ◽  
Geometrical Parameters ◽  
Preliminary Design ◽  
Working Stress ◽  
Support Force ◽  
Internal Forces ◽  
Independent Design ◽  
The Relationship

Built-up columns are widely used in engineering structure, but it is confusing for designers how to determine the parameters of built-up columns. The paper based on the user's basic needs which are the minimum working radius and working load, would simplify working load, support force and hoisting force to the vertex of built-up columns. From the origin of design, and to analyze mechanic behavior of built-up columns, and have found the relationship between internal forces, that is, the axial force, the swing force, the support force, and the working load. In accordance with design experience, the relationship between axial internal stress and its total working stress, critical stress and limit of yielding, had been respectively determined. According to this knowledge to determine the mass and the geometrical parameters of major cross-sections and roots of built-up columns, and a comparison between the results and ones of examples calculations were made, and it was found that the results are reasonable. This will offer a design method of determining the major parameters of built-up columns at the phase of the preliminary design, and improve the independent design capability.

scholarly journals An Improved Parallel Inverse Design Method of EMU Wheel Profile from Wheel Flange Wear Viewpoint

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wenjuan Ren ◽  
Li Li ◽  
Dabin Cui ◽  
Guangxiong Chen
Keyword(s):  
Design Method ◽  
Lateral Displacement ◽  
Dynamic Performance ◽  
Inverse Design ◽  
Force Density ◽  
Contact Points ◽  
Wheel Profile ◽  
Creep Force ◽  
Inverse Design Method ◽  
Profile Optimization

An improved parallel inverse design method is proposed for wheel profile optimization. The dominant merit of this method is the ability to automatically search the target performance curve and obtain the optimized profile without artificial experience. With the help of vehicle system dynamic theory, an EMU model has been established in Simpack, and the dynamic performance is calculated with two profiles, i.e., optimization profile and original profile. The contact and mechanical characters are analyzed by Hertz’s theory, Kalker global algorithm, and CONTACT program. It is found that the rolling radius difference (RRD) with the optimization profile is higher than the original one, especially when the lateral displacement is greater than 3 mm. The creep force density with the optimization profile is significant with a wheelset displacement of 6∼9 mm. Compared with the original one, the distribution of contact points with the optimization profile is more uniform, and the contact position is more biased towards the root of the wheel flange. It means the optimization profile can provide higher RRD value and creep force with large lateral displacement, which is beneficial for reducing wheel flange wear. The dynamic simulation indicates that the optimization profile can help reduce the wheel flange force and wheel flange wear in a sharp curve. Meanwhile, the dynamic behaviors and wheel tread wear on a tangent track or a large curved track are also favorable with the optimization profile.

A design method for rail profiles based on the geometric characteristics of wheel–rail contact

2017 ◽  
Vol 232 (5) ◽  
pp. 1255-1265 ◽  
Author(s):  
Xin Mao ◽  
Gang Shen
Keyword(s):  
Contact Angle ◽  
Design Method ◽  
Dynamic Performance ◽  
Solution Process ◽  
Main Design ◽  
Rail Vehicles ◽  
Angle Difference ◽  
Wheel Profile ◽  
Contact Distribution ◽  
The Given

Designing a proper rail profile carries more significance than designing a wheel profile because of the amount of work and cost involved in the maintenance of rails. A better rail profile will not only help to ensure achieving the desired dynamic performance of rail vehicles but it also extends the service life of rails. This paper presents a unique design method for the design of rail profiles based on the given geometric contact characteristics. The proposed method utilizes a given wheel profile and two typical functions respectively to set the main design targets. The first function is the rolling radii difference and the second one is the contact angle difference. Wheel–rail contact distribution is chosen as the secondary target to prevent stress concentration and the associated fatigue failure. With certain assumptions, the solution process becomes a reverse designed one, which can be solved by using proper discrete numerical methods. Two examples of rail profile designs have been discussed in detail for rigid and independent wheelsets.

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

scholarly journals Investigations on Torsion of the Two-Chords Single Laced Members

2017 ◽  
Vol 25 (2) ◽  
pp. 147-160
Author(s):  
Paweł Lorkowski ◽  
Bronisław Gosowski
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
The Finite Element Method ◽  
Second Moment ◽  
Steel Columns ◽  
Numerical Studies ◽  
Traction Network ◽  
Railway Traction ◽  
Parametric Analyses ◽  
The Relationship

Abstract The paper presents experimental and numerical studies to determine the equivalent second moment of area of the uniform torsion of the two-chord steel single laced members. The members are used as poles of railway traction network gates, and steel columns of framed buildings as well. The stiffness of uniform torsion of this kind of columns allows to the determine the critical loads of the spatial stability. The experimental studies have been realized on a single - span members with rotation arrested at their ends, loaded by a torque applied at the mid-span. The relationship between angle of rotation of the considered cross-section and the torque has been determined. Appropriate numerical model was created in the ABAQUS program, based on the finite element method. A very good compatibility has been observed between experimental and numerical studies. The equivalent second moment of area of the uniform torsion for analysed members has been determined by comparing the experimental and analytical results to those obtained from differential equation of non-uniform torsion, based on Vlasov’s theory. Additionally, the parametric analyses of similar members subjected to the uniform torsion, for the richer range of cross-sections have been carried out by the means of SOFiSTiK program. The purpose of the latter was determining parametrical formulas for calculation of the second moment of area of uniform torsion.

Minimum Energy Control of Multibody Systems Utilizing Storage Elements

2009 ◽  
Author(s):  
Werner Schiehlen ◽  
Makoto Iwamura
Keyword(s):  
Multibody Systems ◽  
Optimal Trajectory ◽  
Design Method ◽  
Equations Of Motion ◽  
Minimum Energy ◽  
Operating Time ◽  
Minimum Energy Control ◽  
Robot Systems ◽  
Optimal Design Method ◽  
The Relationship

In this paper, we consider the problem to minimize the energy consumption for controlled multibody systems utilizing passive elastic elements for energy storage useful for robot systems in manufacturing. Firstly, based on the linearized equations of motion, we analyze the relationship between the consumed energy and the operating time, and the optimal trajectory using optimal control theory. Then, we verify the analytical solution by comparing with the numerical one computed considering the full nonlinear dynamics. After that we derive a condition for the operating time to be optimal, and propose the optimal design method for springs. Finally, we show the effectiveness of the design method by applying it to a 2DOF manipulator.

A synergy-column envelope meshing pair profile for single screw compressors

2018 ◽  
Vol 233 (4) ◽  
pp. 1383-1391 ◽  
Author(s):  
Feilong Liu ◽  
Junhao Feng ◽  
Jia Xie ◽  
Quanke Feng ◽  
Martijn Van Den Broek ◽  
...  
Keyword(s):  
Design Method ◽  
Optimal Combination ◽  
Stable Operation ◽  
Single Screw ◽  
Tooth Width ◽  
Operational Life ◽  
Column Design ◽  
Manufacturing Methods ◽  
Operation Results ◽  
The Relationship

Multi-column envelope engaging couples have been proposed for single screw compressors to reduce the friction and prolong the operational life. However, little is mentioned about the relationship between columns at opposite sides of the star-wheel teeth. An imbalance in the lubricant film forces would appear and influence the lubrication between the tooth and the groove. During a real design process, it is necessary to try several times for each different type of compressor to find the optimal combination of columns. In part, due to the large number of columns, it also makes both manufacturing processing and product testing difficult. In this paper, a synergy-column design method and its related manufacturing methods are presented. The locations and relationships of the designed columns can be prescribed by given the tooth width. Manufacturing of the rotor and star-wheel shows the new design method can be more efficient through processing. The stable operation results prove that the synergy-column envelope meshing pair can solve the star-wheel’s wear-out problem.

scholarly journals Analysis of Post Loan Disbursement Allocation and Performance of Non-Prime Household Loan in Microfinance Banks in Kenya

2017 ◽  
Vol 03 ◽  
pp. 42
Author(s):  
Bernard Ndirangu Wachira ◽  
Humphrey Opiyo Omondi ◽  
Josphat K. Kinyanjui ◽  
◽  
◽  
...  
Keyword(s):  
Financial Management ◽  
Design Method ◽  
Wald Test ◽  
Grameen Bank ◽  
Credit Risks ◽  
Training Policy ◽  
The Government ◽  
And Performance ◽  
Descriptive Survey ◽  
The Relationship

The part played by non-prime household loans in improving the lives of many people who cannot afford collateral globally cannot be ignored. Many Microfinance Banks in many economies worldwide have tried to maintain the Grameen Bank Model of granting microloans, mainly non-prime household loans. However, the credit risks associated with this initiative hamper the pace at which the granting of this credit facility is expected to grow. This study intends to explore the relationship between the post loan disbursement allocation and the performance of non-prime household loans in the Microfinance Banks in Kenya. The theory associated to this study is the Credit Risk Theory. This theory, which is regarded as credit structural theory, was developed by Merton in 1972. The descriptive survey research design method was applied, and the sample size was 150 respondents. The data-collection tool used was a questionnaire. A logistic regression analysis was conducted for the purpose of predicting non-prime household performance in the Microfinance Banks using training budget, recoveries budget, percentage of training budget, and percentage of recoveries budget as predictors. The Wald test shows that training budget, recoveries budget, and percentage of training budget were good predictors, making a significant contribution to prediction. The percentage of budget on recoveries was not a significant predictor. The Microfinance Banks should enhance the performance of non-prime household loans through capacity building to the borrowers and educate the borrowers on dangers of enforced loan recoveries. The government, through the Central Bank of Kenya, should have a training policy for the Microfinance Banks so that they can enlighten the borrowers on proper financial management to avoid conflicts with borrowers during loan recoveries.

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