Simulation of Low Speed Transition Curve Negotiation and Air Suspension Control to Prevent Wheel Load Reduction of Railway Vehicle

2005 ◽  
Author(s):  
Yoshihiro Suda ◽  
Wenjun Wang ◽  
Hisanao Komine ◽  
Yoshi Sato ◽  
Takuji Nakai ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Control Device ◽  
Transition Curve ◽  
Railway Vehicle ◽  
Load Reduction ◽  
Air Spring ◽  
Wheel Load ◽  
Inner Pressure ◽  
Air Suspension ◽  
Curve Negotiation

This paper presents the curving performance of railway vehicles with Air Suspensions. Air Suspensions sometimes cause reduction of Wheel Load at transition curve negotiation. The axle spring of leading axle outside and air spring of leading bogie outside will extend when passing the exit transition curve because of the distortion of the track plane. Because Air Suspension has an automatic leveling function that each air spring is controlled by Leveling Valve to maintain a constant length, air in the extended spring exhaust through Leveling Valve to reduce the pressure of this air spring in order to make it back to original length. So the air spring pressure of leading bogie outside reduces furthermore and Wheel Load of leading axle outside reduces severely. This may be the reason of derailment. The distortion of track plane unbalances inner pressure of Air Suspensions and vertical load of wheels at entrance transition curve, because of the nonlinear characteristic of Air Suspension system caused by the Leveling Valve. Computer simulation of low speed transition curve negotiation shows that the lower running speed is, the more severe unbalance of Air Suspension inner pressure and Wheel Load become. The reduction of 1st axle outside wheel at exit transition curve is depended on this Wheel Load unbalance phenomena at circular curve. And this running process influences the after behavior of railway vehicle. The simulation also shows that the longer entrance transition curve is, the more severely the 1st axle outside Wheel Load reduces. The full-scale bench experiments gave the result as nearly same as computer simulation. A new concept control device is proposed to prevent the reduction of Wheel Load at exit transition curve. Both the simulation and bench experiment proved its control performance of Wheel Load reduction prevention. And proposed control device can also be used in tilting control and kneeling control of railway vehicle. General multi-body dynamics analysis software SIMPACK is used to confirm advantageous effect of proposed control device and full vehicle curve passing simulation shows that derailment coefficient reduced when proposed control device is applied in transition curve negotiation.

Quasi-Static Curve Negotiation Analysis of Railway Vehicle Considering Nonlinear Air Suspension LV and DPV Flow Characteristics

2019 ◽  
Author(s):  
Takayuki Tanaka ◽  
Hiroyuki Sugiyama
Keyword(s):  
Flow Characteristics ◽  
Accurate Prediction ◽  
Small Radius ◽  
Railway Vehicle ◽  
Air Spring ◽  
Wheel Load ◽  
Vehicle Simulation ◽  
Air Suspension ◽  
Derailment Safety ◽  
Curve Negotiation

Abstract Accurate prediction of vehicle curve negotiation performance is critically important for evaluation of railway vehicle safety. Although multibody dynamics vehicle simulation has been widely utilized for the vehicle performance evaluation, nonlinearities associated with the air suspension behavior are vastly simplified and the air mass flows of the leveling valve (LV) and differential pressure valve (DPV) are neglected in many cases. It is, however, known that changes in the air spring pressure caused by the LV and DPV make a non-negligible impact on the vertical wheel load variation and the derailment safety in small radius curved tracks. Therefore, this paper presents a numerical procedure for the analysis of the coupled vehicle and air suspension system behavior, considering nonlinearities associated with LV and DPV flow characteristics. To enable quick and accurate prediction of the history-dependent LV-induced wheel load unbalance and its impact on the derailment safety, quasi-static vehicle motion solvers for the fully coupled vehicle and air spring system flow equations are developed. Several numerical examples are presented to demonstrate the simulation capabilities developed in this study and numerical results are validated against the test data.

Prediction of the Probability of Rail Vehicle Derailment During Grade Crossing Collisions

1982 ◽  
Vol 104 (2) ◽  
pp. 119-132 ◽  
Author(s):  
D. B. Cherchas ◽  
G. W. English ◽  
N. Ritchie ◽  
E. R. McIlveen ◽  
C. Schwier
Keyword(s):  
Computer Simulation ◽  
Preliminary Investigation ◽  
Lateral Force ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Wheel Load ◽  
Road Vehicle ◽  
Rail Vehicle ◽  
Derailment Coefficient ◽  
Grade Crossing

A mathematical model and digital computer simulation are developed to analyze the dynamics of railway and road vehicles during grade crossing collisions. The main objective of the simulation is to relate the probability of derailment to railway vehicle speed; however, a variety of other response characteristics such as railway and road vehicle structure deformation and road vehicle dynamic response can be examined. The criterion for derailment is based on the derailment coefficient, i.e., ratio of wheel flange/railhead lateral force to vertical wheel load. More specifically, the computer simulation utilizes a relationship between the probability of wheel climb commencing and the derailment coefficient, established by Japan National Railways based on their experimental test program. A preliminary investigation is made of the sensitivity of the derailment probability to various collision situations, with the emphasis on increasing rail vehicle speed. Conclusions and recommendations based on this analysis are presented.

scholarly journals Evaluation of Dynamic Load Reduction for a Tractor Semi-Trailer Using the Air Suspension System at all Axles of the Semi-Trailer

Actuators ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 12
Author(s):  
Dang Viet Ha ◽  
Vu Van Tan ◽  
Vu Thanh Niem ◽  
Olivier Sename
Keyword(s):  
Dynamic Load ◽  
Pearson Correlation ◽  
Suspension System ◽  
Leaf Spring ◽  
Load Reduction ◽  
Full Model ◽  
Air Spring ◽  
Suspension Systems ◽  
Air Suspension ◽  
Spring Suspension

The air suspension system has become more and more popular in heavy vehicles and buses to improve ride comfort and road holding. This paper focuses on the evaluation of the dynamic load reduction at all axles of a semi-trailer with an air suspension system, in comparison with the one using a leaf spring suspension system on variable speed and road types. First, a full vertical dynamic model is proposed for a tractor semi-trailer (full model) with two types of suspension systems (leaf spring and air spring) for three axles at the semi-trailer, while the tractor’s axles use leaf spring suspension systems. The air suspension systems are built based on the GENSYS model; meanwhile, the remaining structural parameters are considered equally. The full model has been validated by experimental results, and closely follows the dynamical characteristics of the real tractor semi-trailer, with the percent error of the highest value being 6.23% and Pearson correlation coefficient being higher than 0.8, corresponding to different speeds. The survey results showed that the semi-trailer with the air suspension system can reduce the dynamic load of the entire field of speed from 20 to 100 km/h, given random road types from A to F according to the ISO 8608:2016 standard. The dynamic load coefficient (DLC) with the semi-trailer using the air spring suspension system can be reduced on average from 14.8% to 29.3%, in comparison with the semi-trailer using the leaf spring suspension system.

scholarly journals Prediction of railway wheel load unbalance induced by air suspension leveling valves using quasi-steady curve negotiation analysis procedure

2019 ◽  
Vol 234 (1) ◽  
pp. 19-37
Author(s):  
Takayuki Tanaka ◽  
Hiroyuki Sugiyama
Keyword(s):  
Dynamic Simulation ◽  
Safety Evaluation ◽  
Analysis Procedure ◽  
Small Radius ◽  
Computational Time ◽  
Negotiation Analysis ◽  
Wheel Load ◽  
Air Suspension ◽  
Vehicle Motion ◽  
Curve Negotiation

While air suspensions are widely utilized for passenger railway vehicles as secondary suspension, initial lever angle setting of the air spring levelling valve can make a non-negligible impact on the residual wheel load unbalance in curve negotiation on small radius curved tracks. To enable accurate and quick prediction of the levelling valve-induced residual wheel load unbalance for vehicle safety evaluation, this study proposes a new quasi-steady curve negotiation analysis procedure considering the detailed thermodynamic air suspension system model that accounts for the nonlinear airflow characteristics of levelling valve and differential pressure valves. This approach allows for eliminating a limitation of existing full dynamic simulation models associated with high computational intensity that prevents quick safety evaluation with long-distance simulation under actual railway operating scenarios. A co-simulation scheme for the quasi-steady vehicle motion solver is also proposed to further improve the computational efficiency with explicit force–displacement coupling. Several numerical examples are presented to demonstrate the proposed quasi-steady vehicle motion solver for prediction of levelling valve-induced residual wheel load unbalances in small radius curved tracks. The numerical results are compared with those of the dynamic simulation model and validated against the test data. It is demonstrated that computational time is substantially decreased by the proposed approach while accurately predicting the levelling valve-induced residual wheel load unbalance caused by the initial offset of lever angles on small radius curved tracks.

On the Planning and Construction of Railway Curved Track

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Sono Bhardawaj ◽  
Rakesh Chandmal Sharma ◽  
Sunil Kumar Sharma ◽  
Neeraj Sharma
Keyword(s):  
High Speed ◽  
Time Derivative ◽  
Railway Track ◽  
Lateral Acceleration ◽  
Transition Curve ◽  
Railway Vehicle ◽  
Geometric Conditions ◽  
Curve Track ◽  
Curved Track ◽  
Transition Curves

Increasing demand for railway vehicle speed has pushed the railway track designers to develop high-quality track. An important measure of track quality is the character of the transition curve track connecting different intersecting straight tracks. A good transition curve track must be able to negotiate the intermittent stresses and dynamic effects caused by changes in lateral acceleration at high speed. This paper presents the constructional methods for planning transition curves considering the dynamics of movement. These methods consider the non-compensated lateral acceleration, deviation in lateral acceleration and its higher time derivatives. This paper discusses the laying methods of circular, vertical and transition curves. Key aspects in laying a curved track e.g. widening of gauge on curves are discussed in this paper. This paper also suggests a transition curve which is effective not only from a dynamic point of view considering lateral acceleration and its higher time derivative but also consider the geometric conditions along with the required deflection angle.

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