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Derailment Analysis of High-Speed Railway Vehicle Bogies
Yung-Chang Cheng1,Chern-Hwa Chen
2 ,Che-Jung Yang
3
1,3Department of Mechanical and Automation Engineering
National Kaohsiung First University of Science and Technology Kaohsiung, Taiwan2Department of Civil and Environmental Engineering
National University of Kaohsiung
Kaohsiung, Taiwan
[email protected], [email protected]
Keywords:component; derailment quotient; nonlinear creep model; twelve degrees of freedomsystem
Abstract:Based on the heuristic nonlinear creep model, the nonlinear coupled differential equationsof the motion of a 12 degree-of-freedom (12-DOF) bogie system which takes account of the lateral
displacement, vertical displacement, the roll angle and the yaw angle of the each wheelset and the
bogie frame, moving on curved tracks are derived. The nonlinear creep forces and moments are
constructed via the saturation constant of the nonlinear creep model in completeness. The effect of
the suspension parameters of a bogie system on the derailment quotient is investigated. Results
obtained in this study show that the derailment quotient of a bogie system increases as the vehicle
speed increases. In addition, the derailment quotient of a bogie system is generally decreased with
the increasing values of suspension parameters.
Introduction
Running safety, especially derailment behavior, of a high speed railway vehicle is a very important
topic. The problem of achieving high-speed operation without the derailment has always been of
interest to vehicle designers.
The studies on the dynamic stability of a bogie running on a curved track considering the linear
and nonlinear creep forces can been found in a number of literatures [1-4]. Based on the linear creep
model without considering the creep moments between wheels and rails, the curving performance
of the unsymmetric bogie was presented by Wickens [1].The dynamic stability of a bogie with
variable yaw constraint suspension was studied by Scheffel et al . [2]. Utilizing the nonlinear creep
model, Lóránt and Stépán [3] studied the relations between the nonlinear creep forces and the flange
clearance. Based on the heuristic nonlinear creep model, Dukkipati et al . [4] illustrated the steady
state curving behavior of a conventional bogie and an unconventional bogie. The comparative studyon the steady state curving performance and the dynamic stability of some unconventional bogies
designs is investigated. In the previous studies, the inertia forces of the bogie frame and the
nonlinear creep moments were not considered.
Running safety is an important subject in the dynamic behavior of railway vehicle. Mechanism
of derailment for railway vehicle has been investigated for many years [5-7]. Wu and Zeng [8] studied
the influences of the flange contact angle, friction coefficient and primary suspension forces on the derailment safety.
For the vehicle-bridge system, the theory of energy random analysis for train derailment on bridge is investigated by
Xiang and Zeng [9]. They examined the criteria of energy increment for judging train derailment and the whole
process of train derailment on bridge. A new criterion for prediction of wheelset is presented by Durali
and Jalili [10] studied and compared the capability for prediction of wheelset derailment by a new
derailment criterion and the derailment coefficient. Finally, Francesco et al . [11] presented andcompared the numerical analysis of mathematical models and the experimental results on
derailment of a full-scale vehicle model on roll rig.
Applied Mechanics and Materials Vols. 110-116 (2012) pp 186-195Online available since 2011/Oct/24 at www.scientific.net © (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMM.110-116.186
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,www.ttp.net. (ID: 130.130.37.84, University of Wollongong, Wollongong, Australia-18/06/13,14:38:08)
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The derailment analysis of vehicle models [5−11] is achieved via the linear creep model. In
practice, the nonlinear creep forces and moments are highly sensitive to the hunting stability and
dynamic response of railway vehicles [12]. Even though the equations of the motion of a ten
degrees of freedom system can be found in Lee and Cheng [12]; nevertheless, the vertical
displacement and roll angle of a bogie frame are not considered. In addition, the suspension force in
the vertical direction and the suspension moment in the longitudinal direction acting on a bogieframe were not provided.
In this study, the nonlinear differential equations of motion of the bogie modeled by the 12-DOF
system are derived using the heuristic nonlinear creep model. The dynamic response of the bogie
with earthquake forces is evaluated by the fourth-order Runge-Kutta integration scheme. The
derailment quotients of the left wheel of front wheelset are calculated with various speeds of bogie
and suspension parameters. Finally, the running safety index of a bogie, the derailment quotient, is
presented and compared using the nonlinear creep model for various vehicle speeds and suspension
parameters.
Differential Equations of Motion
Equations of Motion of Bogie Frame.Consider a bogie, as shown in Figures 1 and 2, moving on
curved tracks. The governing equations of motion for lateral displacement y , vertical displacement
z , roll angle φ , and yaw angle ψ of the bogie frame are 2
t syt se t
Vm y F ( )m g
gR φ = + − , (1)
2
t szt se t
Vm z F 1 m g
gR φ
= − +
, (2)
x t sxtI Mφ = , (3)
z t sztI Mψ = , (4)
where V is the forward speed of the bogie and R is the radius of the curved track. The physical
quantities sytF , sztF , xI , zI , sxtM , sztM and m are defined in the Lee and Cheng [12] and Appendix.
Equations of Motion of Wheelsets.Following the notations used by Lee and Cheng [12], when the
inertia forces and the heuristic nonlinear creep forces and moments are considered, the governing
coupled differential equations of motion for the lateral displacementiy , vertical displacement
iz ,
roll angle iφ , and the yaw angle iψ , of the wheelsets are coupled differential equations
( )
( )
( )
2n
w i Lyi i i i i
n
Ryi i i i i Lyi Ryi
2
syi ext ext w se
Vm y F y , y , ,
R
F y , y , , N N
V F W W m ggR
ψ ψ
ψ ψ
φ
− =
+ + +
+ + − +
, (5)
( )
( )
( )
2n
i se Lzi i i i i
n
Rzi i i i i Rzi Lzi
2
szi ext se ext w
Vm z F y , y , ,
R
F y , y , , N N
V F W W m g
gR
φ ψ ψ
ψ ψ
φ
+ =
+ + +
+ − − +
, (6)
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( )
( )
( )
( ) ( )
( )
wx i wy i
0
n
Ryi Rzi i i i i
n
Rzi Ryi i i i i
nLyi Lzi i i i i
n
Lzij Lyij i i i i Lyi Lzi Ryi Rzi
Rzi Ryi Lzi Lyi Lxi Rxi sx
V VI I
r R
R F y , y , ,
R F y , y , ,
R F y , y , ,
R F y , y , , R N R N
R N R N M M M
φ ψ
ψ ψ
ψ ψ
ψ ψ
ψ ψ
= −
+
−
+
− + +
− + + + +
i exiM+
, (7)
( )
( )
( )
( )
( ) ( )
n
wz i wy i Rxi Ryi i i i i
0
n
Ryi Rxi i i i i
n
Lxi Lyi i i i i
n
Lyi Lxi i i i i
nRxi Ryi Lxi Lyi Lzi i i i i
n
Rzi i
VI I R F y , y , ,
r
R F y , y , ,
R F y , y , ,
R F y , y , ,
R N R N M y , y , ,
M y ,
ψ φ ψ ψ
ψ ψ
ψ ψ
ψ ψ
ψ ψ
= − +
−
+
−
+ + +
+
( )i i i sziy , , Mψ ψ +
, (8)
where the subscript i, i 1, 2= , in the physical quantities in this paper represent the corresponding
physical quantities of the front and the rear wheelset, respectively. V is the forward speed of the
bogie. n
Rxi i i i iF (y , y , , )ψ ψ , n
Ryi i i i iF (y , y , , )ψ ψ , n
Rzi i i i iF (y , y , , )ψ ψ , n
Lxi i i i iF (y , y , , )ψ ψ , n
Lyi i i i iF (y , y , , )ψ ψ
and n
Lzi i i i iF (y , y , , )ψ ψ are the x, y and z components of the creep forces of the right wheel and the
left wheel, respectively, n
Rxi i i i iM (y , y , , )ψ ψ , n
Rzi i i i iM (y , y , , )ψ ψ , n
Lxi i i i iM (y , y , , )ψ ψ andn
Lzi i i i iM (y , y , , )ψ ψ are the creep moments in the z direction with respect to the right wheel and the
left wheel, respectively. The other physical parameters are all defined in the Lee and Cheng [12]
and Appendix.A heuristic nonlinear creep model, which combines the Kalker’s linear creep theory with a creep
force saturation representation, is used in the analysis. The nonlinear creep forces and the nonlinear
creep moments are given as (Lee and Cheng [12])*n *
jxi i i i i i jxiF (y , y , , ) Fψ ψ α = , (9a)
*n *
jyi i i i i i jyiF (y , y , , ) Fψ ψ α = , (9b)
*n *
zi i i i i i jziM (y , y , , ) Mψ ψ α = , (9c)
where the subscript j, j L, R = , in the physical quantities in this paper represent the corresponding
physical quantities of the right wheel and the left wheel, respectively. *
xiF , *
jyiF and *
ziM are the linear
creep forces and the linear creep moments evaluated from the Kalker’s linear theory
* 33 LLxi i
0
f r aF V(1+ ) a
V R r ψ
= − − −
, (10a)
* 11 12Lyi i L i i i L
0
f f V VF (y +r V ) ( )
V V R r φ ψ ψ δ = − − − − − , (10b)
* 12 22Lzi i i L i i L
0
f f V VM y V r
V V R r ψ φ ψ δ
= − + − − −
, (10c)
* 33 R Rxi i
0
f r aF V(1 ) a
V R r ψ
= − − − +
, (11a)
* 11 12Ryi i R i i i R
0
f f V VF (y +r V ) ( δ )
V V R r
φ ψ ψ = − − − − + , (11b)
* 12 12Rzi i i R i i R
0
f f V VM y V r
V V R r ψ φ ψ δ
= − + − − +
. (11c)
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By assuming that the roll angle and the yaw angle of each wheelset are small in this paper, the
nonlinear creep forces and moments with respect to the left wheel and the right wheel are given byn *n *n
Lxi Lxi Lyi iF F F ψ = − , *n *n
Lyi Lxi i LyiF F Fψ = + , ( )n *n
Lzi Lyi L iF F δ φ = +
(12a)
( )n *n
Lxi Lzi L i iM M δ φ ψ = + , *n
Lzi LziM M= (12b)
n *n *nRxi Rxi Ryi iF F F ψ = − , *n *n
Ryi Rxi i RyiF F Fψ = + , ( )n *nRzi Ryi R iF F δ φ = − − (13a)
( )n *n
Rxi Rzi R i iM M δ φ ψ = − − , *n
Rzi RziM M= (13b)
The saturation constant iα is (Lee and Cheng [12])
2 3
i i i i
i
i
i
i
1 1 1 for 3
3 27
1 for 3
β β β β β
α
β β
− + ≤
=
≥
(14)
where
Ri Li
i 2
β β
β
+=
,
( ) ( )2 2
* *
jxi jyi
ji
F F
N β µ
+
= (15)
From the static force equilibrium in the vertical direction, the normal forces of the left wheel and
the right wheel in the vertical direction,Lzi N and
Rzi N , normal forces of the left wheel and the right
wheel in the lateral direction, Lyi N and Ryi N , can be obtained and given in Lee and Cheng [12]. By
assuming that the lateral displacements of the contact points from their equilibrium position, the
position vectors of the contact points,LxiR ,
LyiR ,LziR ,
RxiR ,RyiR and
RziR , can be obtained. (Lee and
Cheng [12]) Therefore, summation moments in the longitudinal direction,Ryi Rzi Lyi LziR N R N+ and
Rzi Ryi Lzi LyiR N R N− − , summation moments in the vertical direction,Rxi Ryi Lxi LyiR N R N+ , can be obtained.
From the Fig. 1, the suspension forces of wheelsets in the lateral direction,syiF , the suspension
forces in the vertical direction, sziF , the suspension moments in the longitudinal direction, sxiM , the
suspension moments of wheelsets in the vertical direction,sziM , acting on the wheelsets, the
external moment,exiM , due to the external forces acting on the each wheelset, can be derived as
i
syi py i py i py 1 t py T t
i
py 2 t py t py t py T t
F 2K y 2C y ( 1) 2K L 2K h
( 1) 2C L 2K y 2C y 2C h
ψ φ
ψ φ
= − − − − +
− − + + +
, (16a)
szi pz t pz t pz i pz iF 2K z 2C z 2K z 2C z= + − − , (16b)
2 2 2 2
sxi pz 1 t pz 1 t 1 pz i 1 pz iM 2K b 2C b 2b K 2b Cφ φ φ φ = + − − , (16c)
2 2 2 2
szi px 1 t px 1 t px 1 i px 1 iM 2K b 2C b 2K b 2C bψ ψ ψ ψ = + − − , (16d)
2
exi ext se i
V
M hW gR φ φ
= − − . (16e)
From Figure 1, the suspension forces of a bogie frame in the lateral direction, sytF , the
suspension forces of a bogie frame in the lateral direction, sztF , the suspension moments of the bogie
frame in longitudinal direction,sxtM , the suspension moments of the bogie frame in vertical
direction,sztM , and the suspension moments in the longitudinal direction,
sxtM , are given as
syt py i py i py i py i py T t
y sy t py sy t py T t
F 2K y 2C y 2K y 2C y 4K h
( 4K 2K )y ( 4C 2C )y 4C h
φ
φ
= + + + −
+ − − + − − −
, (17a)
( ) ( )szt sz pz t sz pz t
pz i pz i
F 2 K 2K z 2 C 2C z
2K z 2C z
= − + − +
+ +
, (17b)
2 2
sxt sz 2 t sz 3 t py T i
2
y T i py T i py T i pz 1 i
2 2
y T t py T t py T t pz 1 i
M 2K b 2C b 2K h y
2C h y 2K h y 2C h y 2K b
4K h y 4C h y 4K h 2C b
φ φ
φ
φ φ
= − − +
+ + + +
− − − +
, (17c)
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2 2 2
szt py 1 px 1 sx 2 t
2 2 2
py 2 px 1 sx 3 t
2 2
y 1 1 py 2 1 px 1 1 px 1 1
2 2
y 1 2 py 2 2 px 1 2 px 1 2
M ( 4K L 4K b 2K b )
( 4C L 4C b 2C b )
2K L y 2C L y 2K b 2C b
2K L y 2C L y 2K b 2C b
ψ
ψ
ψ ψ
ψ ψ
= − − −
+ − − −
+ + + +
− − + +
. (17d)
For simplicity, one assumes that the constraint functions is linear for a conical wheel on a knife-edged rail, so the assumptions with respect to the wheel and rail geometry are given in Lee and
Cheng [12]. After substituting the equations given above into equations (5)−(8) and neglecting the
high order terms and the influence of the vertical central displacement of the wheelset on the lateral
displacement, one obtains the following coupled nonlinear differential equations
( )
( )
( )
2
i 11w i i i
0 i 11i 12i i ext w se
2 2
ext extext w se i syi
2 f Vm y y V
R V
2r f 2 f V W m g
V R V
V W V W W m g F
gR gR
α ψ
α α ψ φ φ
φ φ
− = − −
− − − − +
− + + + +
, (18)
22
i 11 i 11i se i i i i szi
20 i 11i 12 i 12 i 12
i i i i i
0
2 f 2 f Vm z y y F
R V V
2r f 2 f 2 f 2 f
V V R r
λ α α φ φ φ
α α α λ α φψ φ φ φ
+ = − − +
− − + +
, (19)
( )
( )
2
i 12wx i wy i i
0 o
22ext
ext w se i
i 11 o i 12i 0 i
2
ext i 12ext w se i 0
2 o i 11i 12 i
2 f V VI I y
r R r
V W W m g y
gR
2 f (a r ) 2 f y a r V V
V W 2 f W m g a a r
gR R
2r f 2 f a
V
λ α φ ψ
φ λ
α λ α λ ψ
α φ λφ λ
α λ α φ λ
− − =
− + +
+
− − +
+ + + + +
+ − +
( )0 i exi
2
i 22i 11 o i sxi
o
r M
2 f 2 f (a r ) M
r
φ
α λ α λ ψ
+
+ + + +
, (20)
( )
( )
i 33 i 12wz i i i szi
o
o i 12wy i i 12 i
o
2
extext w se i
22i 33 i 22 i
i 33 22
2a f 2 f I y y M
r V
2r f V I 2 f
r V
V W W m g a
gR
2a f 2 f 2 a f f
V V R
λα α ψ
α φ α ψ
φ λψ
α α α ψ
= − + +
− − −
+ + +
− + + +
. (21)
As a result, equations (1)−(4) and (18)−(21) form the twelve governing differential equations ofmotion of the system.
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Drailment Analysis
Running safety is one of important factors for dynamic behavior of railway vehicles. The
derailment quotient is adopted to investigate the running safety of railway vehicle. In this study,
because the lateral displacement, vertical displacement, roll angle and yaw angle of a wheelset are
considered, the derailment quotient can be derived completely. The derailment quotient of the left
wheel of the front wheelset of the front bogie, L
L
QP
, (Figure 3) is given as (Matsuo [6])
n
Ly1 Ly1L
nL Lz1 Lz1
F NQ
P F N
+=
+ (22)
where LQ is the contact force acting in lateral direction on the left wheel, LP is the contact force
acting in vertical direction on the left wheel. Additionally, Ly1F and Lz1F are creep forces in the lateral
direction and vertical direction, respectively. Ly1 N and Lz1 N are normal forces in the lateral direction
and vertical direction, respectively.
Numerical ResultBased on the system parameters in the Table I. [13, 14], this paper examines the derailment
quotients of a bogie system. Firstly, the Runge-Kutta fourth-order method is employed to
investigate the time responses for the wheelset. The time history of the nonlinear contact forces of
the left wheel of the front wheelset in the lateral and vertical direction evaluated by Equation (12)
can be obtained. Finally, the RMS (Root-Mean-Square) values of the derailment quotients evaluated
by Equation (28) are presented. For the present problem studied, the time steps of the dynamic
response of the bogie and the time history of earthquake forces are taken to be the same. As such,
the stable time step length of the Runge-Kutta fourth-order scheme is given by 0.005 s.
Figure 4 shows the effect of speeds on the derailment quotients without considering the
earthquake forces with the various primary suspensionxK and
yK . Generally, the derailment
quotients increase as the speeds increase. Moreover, the difference of the derailment quotients for
the variances of the stiffness xK and yK can be neglected as the speeds are lower than 400 km/h.
In Figure (4a), when the speeds exceed 400 km/h, the derailment quotients evaluated by the high
values of xK are greater than those obtained by the low values of xK . However, in Figure (4b), the
derailment quotients evaluated using the low values of yK are greater than those obtained by the
high values of yK as the speeds increase.
Figure 5 presents the effect of speeds on the derailment quotients without considering the
earthquake forces with the various secondary suspension sxC and syC . The derailment quotients are
increased when the vehicle speeds are increased. Furthermore, the longitudinal and lateral damping
of secondary suspension, sxC and syC , have only marginal influence on derailment quotients as thevehicle speed is small. In Figure (5a), the derailment quotients evaluated using the high values of
longitudinal damping sxC are greater than those obtained using the low values of sxC when the
vehicle speed exceeds a critical value of approximately 300 km/h. In addition, the derailment
quotients obtained from the low value of lateral damping syC are consistently higher than those
obtained using the high value of syC . From Figures 4 and 5, it is seen that the derailment quotients
can be reduced as the low values ofx
K and sxC , and the high values ofy
K and syC are applied in
the suspension system of a bogie.
ConclusionThis study has utilized a heuristic nonlinear creep model to analyze the derailment behavior of a
high-speed railway vehicle bogie system moving on curved tracks. The dynamics of the railway
vehicle bogie have been fully described utilizing a 12-DOF model comprising the lateral
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displacement, vertical displacement, roll angle and yaw angle of each wheelset and the bogie frame.
The effects of the suspension parameters on the derailment quotients are presented. Overall, the
results have shown that the derailment quotients can be reduced as the low values of xK and sxC ,
and the high values of yK and syC are used in the suspension system of the bogie.
Tab1. Data of the System Parameters [13, 14]Parameters Value
Wheelset mass wm 1117.9= kg
Bogie frame mass tm 350.26= kg
Roll moment of the inertia of the wheelset wxI 608.1= kg-m2
Spin moment of the inertia of the wheelset wyI 72= kg-m2
Yaw moment of the inertia of the wheelset wzI 608.1= kg-m2
Roll moment of inertia of bogie frame txI 300= kg-m2
Yaw moment of the inertia of the bogie frame tzI 105.2= kg-m2
Wheel radius 0r 0.43= m
Half of the track gauge a 0.7175= m
Wheel conicity 0.05λ =
Half of the primary longitudinal spring arm 11.0= m
Half of the primary longitudinal damping arm 11.0= m
Half of the secondary longitudinal spring arm 21.18= m
Half of the secondary longitudinal dampingarm 3
1.4= m
Half of the primary lateral spring arm 1L 1.28= m
Half of the primary lateral damping arm 2L 1.5= m
Height of the external weight above the centerof gravity of the wheelset
h 1.4= m
Vertical distance from the wheelset center ofthe gravity to the secondary suspension Th 0.47= m
Longitudinal stiffness of the primarysuspension
5
pxK 9 10= × N/m
Lateral stiffness of the primary suspension5
pyK 3.9 10= × N/m
Vertical stiffness of the primary suspension5
pzK 6 10= × N/m
Vertical damping of the primary suspension4
pzC 4 10= × N-s/m
Longitudinal stiffness of the secondarysuspension
4
sxK 3.5 10= × N/m
Lateral stiffness of the secondary suspension4
syK 3.5 10= × N/m
Vertical stiffness of secondary suspension5
szK 3.5 10= × N/m
Longitudinal damping of the secondarysuspension
4
sxC 3.2 10= × N-s/m
Lateral damping of the secondary suspension 4
syC 1 10= × N-s/m
Vertical damping of secondary suspension4
szC 4 10= × N-s/m
Lateral creep force coefficient6
11f 2.212 10= × N
Lateral/spin creep force coefficient 12f 3120= N-m2
Spin creep force coefficient 22f 16= N
Longitudinal creep force coefficient6
33f 2.563 10= × N
Radius of curved tracks R 6250= m
Axle load 4W 5.6 10= × N
Coefficient of the friction 0.2µ =
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Figure 1. Two-axle bogie model
Figure 2. The free body diagram of a single wheelset
Figure 3. Contact forces on left wheel
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100 200 300 400 500
Speed V (km/h
0
0.4
0.8
1.2
D e r a i l m e n t q u o t i e n t
(a)
K px = 900 kN/m
K px = 1800 kN/m
dangerous region
safe region
100 200 300 400 500
Speed V (km/h
0
0.4
0.8
1.2
1.6
D e r a i l m e n t q u o t i e n t
(b)K
py = 390 kN/m
K py = 150 kN/m
dangerous region
safe region
Figure 4. The effect of vehicle speed on derailment quotient for the various (a) px
K (b) py
K of
primary suspension.
100 200 300 400 500
Speed V (km/h
0
0.4
0.8
1.2
D e r a i l m e n t q u o t i e n t
(a)
Csx = 32 kN-s/m
Csx = 120 kN-s/m
dangerous region
safe region
100 200 300 400 500
Speed V (km/h
0
0.4
0.8
1.2
D e r a i l m e n t q u o t i e n t
(b)
Csy = 10 kN-s/m
Csy = 50 kN-s/m
dangerous region
safe region
Figure 5. The effect of vehicle speed on derailment quotient for the various (a) sxC (b) sy
C ofsecondary suspension.
Applied Mechanics and Materials Vols. 110-116 195
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Mechanical and Aerospace Engineering
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Derailment Analysis of High-Speed Railway Vehicle Bogies
10.4028/www.scientific.net/AMM.110-116.186