A Comparison of the Stability and Curving Performance of Radial and Conventional Rail Vehicle Trucks

1981 ◽  
Vol 103 (3) ◽  
pp. 191-200 ◽  
Author(s):  
D. Horak ◽  
C. E. Bell ◽  
J. K. Hedrick
Keyword(s):  
Shear Stiffness ◽  
Bending Stiffness ◽  
Lateral Stability ◽  
High Shear ◽  
Wear Properties ◽  
Rail Vehicle ◽  
Curving Performance ◽  
Conventional Rail ◽  
The Stability ◽  
Total Shear

This paper compares the lateral stability and steady-state curving performance of radial and conventional rail vehicle trucks. The radial truck has two unique features, it allows direct elastic coupling between the wheelsets and it allows greater total truck shear stiffness for a given bending stiffness. It is shown that the first property allows the radial truck to achieve up to a 40 percent higher critical speed than the conventional truck for equivalent truck total shear and bending stiffness since the direct coupling between the wheelsets allows decoupling of the truck mass from the hunting wheelset masses. The second feature, i.e., greater shear stiffness capability, allows the radial truck to have improved wear properties during the negotiation of tight curves. It is shown that the high shear stiffness property combined with a low bending stiffness reduces the lateral flange force and wheelset angle of attack during flange contact. It is concluded that for routes where the majority of curves are less than 4 deg (greater than 400 m radius) the truck optimized for off-flange performance should have intermediate values of shear stiffness, bending stiffness, and conicity. On the other hand, for routes where the majority of curves are greater than 4 deg, the truck optimized for on-flange performance should have a high shear stiffness and low values of bending stiffness and conicity.

Lateral Stability of Freight Cars With Axles Having Different Wheel Profiles and Asymmetric Loading

1979 ◽  
Vol 101 (1) ◽  
pp. 1-16 ◽  
Author(s):  
J. M. Tuten ◽  
E. H. Law ◽  
N. K. Cooperrider
Keyword(s):  
Dynamic Response ◽  
Strong Influence ◽  
Lateral Stability ◽  
Loading Conditions ◽  
Stability Behavior ◽  
Rail Freight ◽  
Rail Vehicle ◽  
Asymmetric Loading ◽  
Left And Right ◽  
The Stability

The majority of studies of rail vehicle lateral dynamic response have utilized models wherein it is assumed that the loading and geometry of the vehicles are symmetrical left and right and fore and aft. It has been observed that with use North American rail freight vehicles develop transverse wheel profiles that may be different for wheels on a given axle and that may also differ from axle to axle on a given vehicle. As the transverse wheel profiles exert a strong influence on lateral dynamic response by affecting the effective conicity and gravitational stiffness of the wheelset, models capable of having different wheel profiles on the same axle as well as on different axles were developed to investigate the stability behavior. Additionally, these models were formulated so that the effects on stability of asymmetric fore and aft loading conditions, as manifested through gravitational stiffness effects and creep coefficients, could be examined. Results of studies using these models are presented that display characteristics markedly different from those of completely symmetric models. A particularly interesting result is that, in most cases, the lateral stability of vehicles with different wheel profiles on the various axles is strongly sensitive to the direction of motion with results for each direction of motion which may differ radically from symmetric cases.

Analysis on Curve Negotiation Ability of the Rail Vehicle Based on SIMPACK

2013 ◽  
Vol 721 ◽  
pp. 551-555 ◽  
Author(s):  
Li Hua Wang ◽  
An Ning Huang ◽  
Guang Wei Liu
Keyword(s):  
Dynamic Performance ◽  
Lateral Force ◽  
Lateral Stability ◽  
Rail Vehicle ◽  
Body Dynamics ◽  
Curve Track ◽  
The Stability ◽  
Multi Body ◽  
Body Dynamic ◽  
Curve Negotiation

The curve negotiation ability and lateral stability are the important and contradictory indicators when evaluating the dynamic performance of the rail vehicle. And in order to study the stability of the rail vehicle, its curve negotiation ability will be studied firstly. In this paper, the whole multi-body dynamic model of the rail vehicle was proposed based on the theory of multi-body dynamics in the software of Simpack. And the lateral force, derailment and overturning coefficient of the rail vehicle when it passed through a specific curve track with specific speed. Then the curve negotiation ability of the rail vehicle was estimated accurately.

Lateral Stability Behavior of Railway Freight Car System With Elasto-Damper Coupled Wheelset: Part 1—Wheelset Model

1987 ◽  
Vol 109 (4) ◽  
pp. 493-499 ◽  
Author(s):  
A. K. W. Ahmed ◽  
S. Sankar
Keyword(s):  
Lateral Stability ◽  
Conventional System ◽  
Stability Behavior ◽  
Rail Vehicle ◽  
Railway Freight ◽  
Linearized Stability ◽  
Freight Car ◽  
The Stability ◽  
The Mathematical Model ◽  
Railway Freight Car

A general model of single rail vehicle wheelset with elasto-damper coupling between the wheels, has been developed as a first step in developing a railway freight truck model with elasto-damper coupled wheelset (EDCW). By choosing different coupler parameters, various stiffness-damper combinations, as well as rigid axle (conventional wheelset) could be simulated. The mathematical model of EDCW has been validated by comparing the model under limiting cases with those of published results for conventional system. In this paper, the results of linearized stability analysis of EDCW model on tangent track are presented and discussed. The investigation showed that wheelset coupler parameters have significant influence on the stability behavior of the wheelset, and there is an optimal coupler parameter which can improve the wheelset critical speed over the conventional system.

On The Lateral Stability of a Flexible Truck

1983 ◽  
Vol 105 (2) ◽  
pp. 120-125 ◽  
Author(s):  
A. M. Whitman
Keyword(s):  
Asymptotic Expansion ◽  
Geometric Parameter ◽  
Symmetric Function ◽  
Critical Speed ◽  
Numerical Solutions ◽  
Bending Stiffness ◽  
Lateral Stability ◽  
Expansion Parameter ◽  
Entire Structure ◽  
The Stability

Analytic formulae for the critical speed and frequency of an interconnected pair of wheelsets based on an asymptotic expansion in a truck geometric parameter are derived. No restriction is placed on the values of either the shear or bending stiffness; consequently, the entire structure of the stability surface is obtained. The surface is a symmetric function of the two dimensionless stiffnesses and it depends predominantly on their series combination. Expressions are obtained for the local and global extrema and their locations. The frequency varies monotonically from the wheelset kinematic frequency to the rigid truck frequency as a function of stiffness. The results are compared with numerical solutions and found to be accurate in the region of physically obtainable values of the expansion parameter.

scholarly journals Determination of Transverse Shear Stiffness of Sandwich Panels with a Corrugated Core by Numerical Homogenization

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1976
Author(s):  
Tomasz Garbowski ◽  
Tomasz Gajewski
Keyword(s):  
Transverse Shear ◽  
Shear Stiffness ◽  
The Finite Element Method ◽  
Homogenization Procedure ◽  
Plate Structures ◽  
Corrugated Board ◽  
Energy Equivalence ◽  
The Stability ◽  
Global Stiffness Matrix

Knowing the material properties of individual layers of the corrugated plate structures and the geometry of its cross-section, the effective material parameters of the equivalent plate can be calculated. This can be problematic, especially if the transverse shear stiffness is also necessary for the correct description of the equivalent plate performance. In this work, the method proposed by Biancolini is extended to include the possibility of determining, apart from the tensile and flexural stiffnesses, also the transverse shear stiffness of the homogenized corrugated board. The method is based on the strain energy equivalence between the full numerical 3D model of the corrugated board and its Reissner-Mindlin flat plate representation. Shell finite elements were used in this study to accurately reflect the geometry of the corrugated board. In the method presented here, the finite element method is only used to compose the initial global stiffness matrix, which is then condensed and directly used in the homogenization procedure. The stability of the proposed method was tested for different variants of the selected representative volume elements. The obtained results are consistent with other technique already presented in the literature.

Experimental Study on Shear Behavior of Perfobond Connector with Boot Shaped Slots

2019 ◽  
Author(s):  
Zhanchong Shi ◽  
Qingtian Su ◽  
Xinyi He ◽  
Quanlu Wang ◽  
Kege Zhou ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Stiffness ◽  
Shear Capacity ◽  
High Shear ◽  
Test Results ◽  
Precise Location ◽  
Construction Problem ◽  
Circular Holes ◽  
New Type ◽  
Push Out

<p>In order to solve the construction problem of perforating rebars’ precise location and it’s getting through the circular holes for the the conventional perfobond connector, a new type of perfobond connector with boot shaped slots was proposed. This new type perfobond connector has the advantage of convenient construction and pricise location. Three groups of push-out tests with nine specimens were carried out to study the shear capacity of the new type perfobond connector. The effect of the number and the spacing of boot shaped slots on failure modes, shear capacity, peak slip and shear stiffness were mainly studied. The test results show that the new type of perfobond connector with boot shaped slots has a high shear capacity and a good ductility, it could be widely applied on the connection between the steel and the concrete structures.</p>

A Study of the Lateral Stability of Railroad Vehicles Using a Nonlinear Constrained Multibody Formulation

2001 ◽  
Author(s):  
Davide Valtorta ◽  
Khaled E. Zaazaa ◽  
Ahmed A. Shabana ◽  
Jalil R. Sany
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Theory ◽  
Linear Stability Analysis ◽  
Numerical Study ◽  
Operating Conditions ◽  
Lateral Stability ◽  
Railroad Vehicles ◽  
Contact Formulation ◽  
The Stability

Abstract The lateral stability of railroad vehicles travelling on tangent tracks is one of the important problems that has been the subject of extensive research since the nineteenth century. Early detailed studies of this problem in the twentieth century are the work of Carter and Rocard on the stability of locomotives. The linear theory for the lateral stability analysis has been extensively used in the past and can give good results under certain operating conditions. In this paper, the results obtained using a linear stability analysis are compared with the results obtained using a general nonlinear multibody methodology. In the linear stability analysis, the sources of the instability are investigated using Liapunov’s linear theory and the eigenvalue analysis for a simple wheelset model on a tangent track. The effects of the stiffness of the primary and secondary suspensions on the stability results are investigated. The results obtained for the simple model using the linear approach are compared with the results obtained using a new nonlinear multibody based constrained wheel/rail contact formulation. This comparative numerical study can be used to validate the use of the constrained wheel/rail contact formulation in the study of lateral stability. Similar studies can be used in the future to define the limitations of the linear theory under general operating conditions.

Stability of a String in Axial Flow

1985 ◽  
Vol 107 (4) ◽  
pp. 421-425 ◽  
Author(s):  
G. S. Triantafyllou ◽  
C. Chryssostomidis
Keyword(s):  
Stability Analysis ◽  
Frictional Coefficient ◽  
Axial Flow ◽  
Added Mass ◽  
Equation Of Motion ◽  
Bending Stiffness ◽  
Diameter Ratio ◽  
Constant Speed ◽  
Hamilton’S Principle ◽  
The Stability

The equation of motion of a long slender beam submerged in an infinite fluid moving with constant speed is derived using Hamilton’s principle. The upstream end of the beam is pinned and the downstream end is free to move. The resulting equation of motion is then used to perform the stability analysis of a string, i.e., a beam with negligible bending stiffness. It is found that the string is stable if (a) the external tension at the free end exceeds the value of a U2, where a is the “added mass” of the string and U the fluid speed; or (b) the length-over-diameter ratio exceeds the value 2Cf/π, where Cf is the frictional coefficient of the string.

Vehicle Lateral Motion Control Based on Estimated Stability Regions

2017 ◽  
Author(s):  
Yiwen Huang ◽  
Yan Chen
Keyword(s):  
Measurement Errors ◽  
Local Stability ◽  
Stability Region ◽  
Control Method ◽  
Linearization Method ◽  
Stability Control ◽  
Lateral Stability ◽  
Shortest Distance ◽  
The Stability ◽  
Yaw Moment

This paper presents a novel vehicle lateral stability control method based on an estimated lateral stability region on the phase plane of vehicle yaw rate and lateral speed, which is obtained through a local linearization method. Since the estimated stability region does not only describe vehicle local stability, but also define the oversteering and understeering characteristics, the proposed control method can achieve both local stability and vehicle handling stability. Considering the irregular geometric shape of the estimated stability region, a stability analysis algorithm is designed to determine the distance between vehicle states and stability region boundaries. State estimation or measurement errors are also incorporated in the distance calculation. Based on the calculated shortest distance between vehicle states and stability boundaries, a direct yaw moment controller is designed to maintain vehicle states stay within the stability region. CarSim® and Simulink® co-simulation is applied to verify the control design through a cornering maneuver. The simulation results show that the proposed control method can make the vehicle stay within the stability region successfully and thus always operate in a safe manner.

Sign in / Sign up

Export Citation Format

Share Document