Analytical formulae for the design of a railway vehicle suspension system

2001 ◽  
Vol 215 (6) ◽  
pp. 683-698 ◽  
Author(s):  
G R M Mastinu ◽  
M Gobbi ◽  
G D Pace
Keyword(s):  
Standard Deviation ◽  
Dynamic Response ◽  
Optimization Method ◽  
Degree Of Approximation ◽  
The Body ◽  
Vehicle Suspension ◽  
Railway Vehicle ◽  
Body Acceleration ◽  
Railway Vehicles ◽  
Analytical Formulae

A simple two-degree-of-freedom (2DOF) model is used to derive a number of analytical formulae describing the dynamic response of railway vehicles to random excitations generated by vertical track irregularities. The dynamic response is given in terms of standard deviations of a number of relevant performance indices such as body-bogie suspension stroke and body acceleration. The derived analytical formulae can be used either during preliminary design or for other special purposes, especially when approximated results are acceptable. An estimation of the degree of approximation offered by analytical formulae is attempted and the results seem satisfactory. By inspection of the analytical formulae a parameter sensitivity analysis may be readily performed. In the second part of the paper, an optimization method for the improvement of the dynamic behaviour of railway vehicles is introduced. The method, based on multiobjective programming (MOP), is a general one and can be exploited for many engineering purposes. In the paper the method has been applied with the aim of achieving the desired trade-off among conflicting performances such as standard deviation of the body acceleration versus standard deviation of the secondary suspension stroke. As a result, new analytical formulae defining the settings of some relevant vehicle suspension parameters have been derived.

Model Predictive Control Application to Flexible-Bodied Railway Vehicles for Vibration Suppression

2013 ◽  
Vol 10 ◽  
pp. 25-35
Author(s):  
P.E. Orukpe
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
High Speed ◽  
Ride Comfort ◽  
The Body ◽  
Ride Quality ◽  
Linear Matrix ◽  
Railway Vehicle ◽  
Railway Vehicles ◽  
Effective Manner

In this paper, we apply model predictive control (MPC) based on mixed H2/H to active vibration control of the flexibility of railway vehicle to improve ride quality. However, the flexibility in the body of high-speed railway vehicles creates difficulties which in practice may result in the body structure being heavier than what it is supposed to be. The use of active suspension helps to model the vehicle and its flexibility in an effective manner. Conventional control approaches are compared with linear matrix inequality MPC technique using flexible-bodied railway vehicle as an example. The result indicates that the MPC technique performs better in improving ride comfort compared to the passive and classical techniques when flexible modes are present.

A Survey of Railway Vehicle Dynamics Research

1974 ◽  
Vol 96 (2) ◽  
pp. 132-146 ◽  
Author(s):  
E. H. Law ◽  
N. K. Cooperrider
Keyword(s):  
Experimental Research ◽  
Vehicle Dynamics ◽  
Vehicle Suspension ◽  
Railway Vehicle ◽  
Railway Vehicles ◽  
Conflicting Objectives ◽  
Analytical Research

This paper presents a survey of the research concerned with the dynamics of single, conventional railway vehicles. Attention is concentrated on analytical research and only that experimental research that has been performed in conjunction with analytical efforts. The often conflicting objectives for railway vehicle suspension design and the research done to understand the design implications of these objectives are discussed.

Fuzzy Control of Vehicle Suspension System

2011 ◽  
Vol 383-390 ◽  
pp. 2012-2017 ◽  
Author(s):  
Guo Quan Yang ◽  
You Qun Zhao
Keyword(s):  
Fuzzy Control ◽  
Ride Comfort ◽  
Fuzzy Controller ◽  
Suspension System ◽  
The Body ◽  
Vehicle Body ◽  
Vehicle Suspension ◽  
Body Acceleration ◽  
Vehicle Suspension System ◽  
Fuzzy Logic Technique

In this paper, a semi-active suspension system has been proposed to improve the ride comfort, and a 2 DOF vehicle system is designed to simulate the actions of vehicle suspension system. The purpose of a suspension system is to support the vehicle body and increase ride comfort. The aim of the work described in the paper was to illustrate the application of fuzzy logic technique to the control of a continuously damping automotive suspension system. The ride comfort is improved by means of the reduction of the body acceleration caused by the car body when road disturbances from smooth road and real road roughness. Based on MATLAB fuzzy control toolbox, fuzzy controller is designed. Simulation analysis of suspension system is preceded by using MATLAB/Simulink7.0. The result shows that this control can improve the body acceleration, suspension distortion etc.

Simulation Research on the Performance of Vehicle Suspension System

2013 ◽  
Vol 798-799 ◽  
pp. 378-381
Author(s):  
Li Hong Zhou
Keyword(s):  
Transfer Function ◽  
Ride Comfort ◽  
Suspension System ◽  
The Body ◽  
Vehicle Suspension ◽  
Simulation Research ◽  
Body Acceleration ◽  
Suspension Spring ◽  
Evaluation Indexes ◽  
Vehicle Suspension System

Simulation study of the quarter car model was carried out in this paper. The influence of the stiffness of the suspension spring and the damping on the performance of vehicle suspension system was analyzed by the evaluation indexes: transfer function of body acceleration, transfer function of suspension dynamic stroke, transfer function of tire dynamic deflection. The simulation results shown that increasing the stiffness of the suspension spring would reduce the vehicle's ride comfort and increase the value of the first natural frequency of the sprung mass. And increasing the damping would reduce the peak response of the body acceleration which increasing the vehicle's ride comfort, but at the cost of increasing the high frequency vibration.

Semi-Active Suspension Systems for Railway Vehicles Based on Magnetorheological Fluid Dampers

2007 ◽  
Author(s):  
D. H. Wang ◽  
W. H. Liao
Keyword(s):  
Suspension System ◽  
Full Scale ◽  
Vehicle Suspension ◽  
Railway Vehicle ◽  
Mr Fluid ◽  
Railway Vehicles ◽  
Suspension Systems ◽  
Secondary Suspension ◽  
Fluid Dampers ◽  
Track Irregularities

In this paper, a seventeen degree-of-freedom (DOF) model for a full scale railway vehicle integrated with the semi-active controlled magnetorheological (MR) fluid dampers in its secondary suspension system is proposed to cope with the lateral, yaw, and roll motions of the car body, trucks, and wheelsets. The governing equation considering the dynamics of the railway vehicle integrated with MR fluid dampers in the secondary suspension system and the dynamics of the rail track irregularities are developed. The Linear Quadratic Gaussion (LQG) control law using the acceleration feedback is adopted, in which the state variables are estimated from the measurable accelerations with a Kalman estimator. In order to evaluate how the performances of the railway vehicle system integrated with the semi-active controlled MR fluid dampers can be improved, the lateral, yaw, and roll accelerations of the car body, trucks, and wheelsets of a full scale railway vehicle integrated with MR fluid dampers, which are controlled (the semi-active) and uncontrolled (the passive on and passive off) respectively, are analyzed under the random track irregularities based on the established governing equations and the modelled track irregularities. The simulation results not only show the control effectiveness of the railway vehicle with the semi-active suspension system based on MR fluid dampers for railway vehicles, but also illustrate that the semi-active railway vehicle suspension system based on MR fluid dampers combines the merits of the passive on and passive off railway vehicle suspension systems.

scholarly journals Railway Vehicle Pneumatic Rubber Suspension Modelling and Analysis

2018 ◽  
Vol 55 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Marius Adrian Spiroiu
Keyword(s):  
Dynamic Response ◽  
Railway Vehicle ◽  
Railway Vehicles ◽  
Pneumatic Suspension ◽  
Suspension Stiffness ◽  
Secondary Suspension ◽  
Elastic Elements

The pneumatic elastic elements are widely used in the secondary suspension of modern railway vehicles due to their important advantages compared to the conventional ones. In the present paper, the modelling and analysis of the pneumatic suspension is approached, taking into account the main elements, pneumatic enclosures and rubber elements. The analysis performed investigates the influence of relevant parameters on suspension stiffness and on its dynamic response.

scholarly journals Simulation of Energy Absorption Performance of the Couplers in Urban Railway Vehicles during a Heavy Collision

Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 91
Author(s):  
Sunghyun Lim ◽  
Yong-hyeon Ji ◽  
Yeong-il Park
Keyword(s):  
Reaction Force ◽  
Crash Test ◽  
Railway Vehicle ◽  
Buffer System ◽  
Railway Vehicles ◽  
Hydraulic Shock Absorber ◽  
Coupling Buffer ◽  
Absorption Performance ◽  
Different Characteristics ◽  
The Impact

Railway vehicles are generally operated by connecting several vehicles in a row. Mechanisms connecting railway vehicles must also absorb front and rear shock loads that occur during a train’s operation. To minimize damage, rail car couplers are equipped with a buffer system that absorbs the impact of energy. It is difficult to perform a crash test and evaluate performance by applying a buffer to an actual railway vehicle. In this study, a simulation technique using a mathematical buffer model was introduced to overcome these difficulties. For this, a model of each element of the buffer was built based on the experimental data for each element of the coupling buffer system and a collision simulation program was developed. The buffering characteristics of a 10-car train colliding at 25 km/h were analyzed using a developed simulator. The results of the heavy collision simulation showed that the rubber buffer was directly connected to the hydraulic shock absorber in a solid contact state, and displacement of the hydraulic buffer hardly occurred despite the increase in reaction force due to the high impact speed. Since the impact force is concentrated on the vehicle to which the collision is applied, it may be appropriate to apply a deformation tube with different characteristics depending on the vehicle location.

scholarly journals Iodometric Quantitative Analysis Method of Ascorbic Acid in Tablets

2019 ◽  
Vol 70 (10) ◽  
pp. 3555-3560
Author(s):  
Costinela Valerica Georgescu ◽  
Cristian Catalin Gavat ◽  
Doina Carina Voinescu
Keyword(s):  
Ascorbic Acid ◽  
Quantitative Analysis ◽  
Standard Deviation ◽  
Statistical Significance ◽  
The Body ◽  
Water Soluble ◽  
International Standards ◽  
Titration Method ◽  
Normal Limits ◽  
Relative Standard

Ascorbic acid is a water-soluble vitamin provided with strong antioxidant action, that fulfills an important immune protective role of the body against infections and prevents various cancers appearance. The main goal of this study was to exactly quantify pure ascorbic acid in tablets of two pharmaceuticals. Proposed objective consisted in improvement and application of a iodometric titration method in ascorbic acid quantitative analysis. Ascorbic acid content per tablet in both studied pharmaceuticals was 173.84 mg, very close to official stated amount of active substance (180 mg). Allowed percentage deviation from declared content of pure ascorbic acid was only 3.42 %, below maximum value of � 5 % imposed by Romanian Pharmacopoeia 10-th Edition, according to European and International standards. Statistical analysis confirmed experimental obtained results and revealed low Standard Error value SE = 0.214476, which has fallen within normal limits. Confidence Level value (95.0 %) = 0.551328 and Standard Deviation SD = 0.525357. were within normal range of values. Relative Standard Deviation (Coefficient of variation or homogeneity) RSD = 26.268% was found below maximum range of accepted values (30-35%). P value = 7.44. 10-6 was located within normal limits, P [ 0.001, so the experimental obtained results has shown highest statistical significance. Thus, studied titration method can be successfully used in quantitative analysis of ascorbic acid from different samples.

scholarly journals CORRELAÇÃO ENTRE OBESIDADE/SOBREPESO E PRESSÃO ARTERIAL ELEVADA EM ESCOLARES DE UMA CIDADE DO INTERIOR DE SÃO PAULO

2019 ◽  
Vol 11 (1) ◽  
pp. 51-56
Author(s):  
Marcelo José Alves ◽  
Victor Hugo Santos Zangirolamo ◽  
Carlos Augusto Carvalho Filho ◽  
Everton Alex Carvalho Zanuto ◽  
Diane de Vasconcelos Barrionuevo ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Body Mass Index ◽  
Body Weight ◽  
Standard Deviation ◽  
Physical Inactivity ◽  
Pediatric Population ◽  
The Body ◽  
Chronological Age ◽  
Hemodynamic Variables

Currently the Brazilian pediatric population has been exposed to risk factors caused by physical inactivity and poor diet, resulting in an increase in the Body Mass Index (BMI), which can lead to vascular problems even in childhood. The objectivewasto verify the influence of BMIon pressure levels. The sample consisted of 61 children of both sexes, chronological age between six and seven years and regularly enrolled/attending school. These children were evaluated in their hemodynamic variables (systolic -SBP and diastolic –DBP blood pressure), body weight, and height. Mean and standard deviation of participants' ages were 7±0.3 years, SBP had 89.4±10 and DBP of 57±6.9, eutrophic patients had 88.7±1.1 for SBP and 56±5 for DBP,and for those with overweight/obesityof109±5 for SBP and 70.7±8.2 for PAD(p=0.0001).Pearson's correlation for BMI with SBP and DBP was moderate for both, but with beta of 1.53 in linear regression for SBP and 0.96 for DBP. It was concluded thatBMI directly influences systolic and diastolic blood pressure levels and the control of overweight / obesity is necessary at the initial ages of life

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