Advanced Science and Technology Letters
Vol.121 (AST 2016), pp.476-479
http://dx.doi.org/10.14257/astl.2016.121.86
Calibration Test and Correction of Instrumented
Wheelset
HaoBo Lin1,a, Qiang Li1, , Yuqing Yuan1, Rongquan Yu1, Guang Yang1
1
Engineering Research Center of Structure Reliability and Operation Measurement
Technology of Rail Guided Vehicles, Ministry of Education, Beijing Jiaotong University.
Beijing, China, [email protected]
Abstract. Instrumented wheelset is based on original wheelset and it is an
important tool to study wheel-rail force. According to standard GB5599-85,
strain gauges are stuck on plates. Strain signal is acquired by applying vertical
force. Vertical transfer coefficient and vertical on the literal influence
coefficient are 0.7338 and 0.1743 through data processing. Meanwhile, literal
transfer coefficient and literal on the vertical influence coefficient are 2.5403
and 0.0361. Correction formula of literal load and vertical load is deduced by
considering the interaction between the two kinds of load.
Keywords: Instrumented wheelset; Calibration; Transfer coefficient; Load
correction
1
Introduction
As development of high speed train, the wheel-rail force has become the researcher of
increasing attention. In all measurement of wheel-rail force, instrumented wheelset
has the most accurate result [1]. The calibration of instrumented wheelset is to stick the
strain gauge on the wheel, form a specific bridge, and establish the relationship
between the strain and the wheel rail force. The static calibration of the instrumented
wheelset includes the vertical load and the lateral load calibration [2].
2
Calibration principle of wheelset
According to the theory of mechanical force balance and moment balance principle
[3]
, calculation principles are as followed.
Formula of force and moment balance：
(1)
ISSN: 2287-1233 ASTL
Copyright © 2016 SERSC
Advanced Science and Technology Letters
Vol.121 (AST 2016)
* =
+
*
(2)
,
,
and
are gravity of left wheel, right wheel, gear box and axle,
and
are the vertical force of left and right sides.
The transfer coefficient of vertical load and lateral load can be calculated by the
following formula [4].
=0.21*
=0.21*
=0.21*
=0.21*
(3)
(4)
(5)
(6)
The maximum load of calibration is 20kN. Lateral load strain ( ) and vertical
load strain
( ) are corresponding to lateral load Q. After calibration, transfer
coefficient of vertical load
and lateral load , as well as influence coefficient
and
.
3
Calibration experiment
In four vertical load calibration test, vertical load are
=7.4791(kN) and
=5.8195(kN).
according to formula3 are shown in table1.
according to
formula5 are shown in table2.
Table 1.
The calibration of the vertical coefficient
No
(MPa/
kN)
1
0.7
404
2
0.7
271
0.7
338
3
0.7
321
0.7
371
4
0.7
338
0.7
338
0.1
680
0.1
881
0.7
321
Table 2. The coefficient of the vertical load to the lateral load
No
(MPa/k
N)
1
0.1
282
2
0.1
513
0.2
214
3
0.1
598
0.2
413
4
0.1
365
Vertical load transfer coefficient is calculated as:
= (0.7404+0.7271+…+0.7321)/8=0.7338(MPa/kN)
Influence coefficient of vertical load on lateral load is calculated as:
= (0.1282+0.1513+…+0.1365)/8=0.1743(MPa/kN)
Strain time history of lateral load bridge is recorded by strain recorder. And the
magnitude of the applied lateral loads is also recorded. According to linear regression
analysis based on recorded data, lateral load transfer coefficients are shown in Table
3.
Copyright © 2016 SERSC
477
Advanced Science and Technology Letters
Vol.121 (AST 2016)
Table 3. The lateral coefficient of the calibration
No
1
2.3628
2
2.3866
3
2.7074
4
2.7055
Lateral load transfer coefficient is calculated as:
= (2.3628+…+2.7055)/4=2.5403(MPa/kN)
According to linear regression analysis based on recorded data, coefficient of the
lateral load to the vertical load are shown in table 4.
Table 4. The coefficient of the lateral load to the vertical load
No
1
0.0166
2
0.0219
3
0.0502
4
0.0556
The coefficient of the lateral load to the vertical load is calculated as:
= (0.0166+…+0.0556)/4=0.0361(MPa/kN)
4
Load correction
The application of vertical load will have an effect on the output of lateral measuring
bridge. The lateral load will effect vertical bridge output as will. This interaction is
called cross talk. In actual testing process, this kind of cross talk is objective existence
[5-6].
Measurement bridges output of vertical and lateral load are both influenced by
application of vertical and lateral load. So the formulas are as followed.
0.21V  K L  0.21 L  ELV

P 
KV K L  EVL ELV


Q  0.21 L  KV  0.21V  EVL

KV K L  EVL ELV
(7)
Put all coefficient in formula. Modified formula for vertical load and lateral load
are as followed.
 P =1.3674  0.21V -0.0194  0.21 L

Q=0.3950  0.21 L -0.0938  0.21V
5
(8)
Conclusions
(1) Static calibration experiment is carried based on standard GB5599-85. Vertical
transfer coefficient and vertical on the literal influence coefficient are 0.7338 and
0.1743 through data processing. Meanwhile, literal transfer coefficient and literal
on the vertical influence coefficient are 2.5403 and 0.0361.
478
Copyright © 2016 SERSC
Advanced Science and Technology Letters
Vol.121 (AST 2016)
(2) Load correction formula is derived considering coupling of vertical load and
lateral load. The formula can fix cross talk between vertical and lateral load.
References
1.
2.
3.
4.
5.
6.
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Fan, Q., Chen, J.: Theoretical Mechanics, (In Chinese)
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