Proceedings of the IMPLAST 2010 Conference
October 12-14 2010 Providence, Rhode Island USA
© 2010 Society for Experimental Mechanics, Inc.
Establishment and Development of Laboratory Based
Motorcycle Crash Test Facility
C.L. Tan1, S.V. Wong 1, 2
1
Department of Mechanical & Manufacturing Engineering, Faculty of Engineering,
University Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
2
Malaysia Institute of Road Safety Research, 43000 Kajang, Selangor, Malaysia.
Email: [email protected]
ABSTRACT
Road safety researchers have built full scale motorcycle crash test systems to test and verify crashworthiness of
two and four-wheeled vehicles. Different operation method and crash scenarios were simulated to obtain the best
results mimicking real events. Nevertheless, one major drawback in a full scale motorcycle crash test is the
difficulty in conducting a parametric study. Therefore, this study aims to focus in the development of a laboratory
based motorcycle crash test facility which includes the design and development of a movable barrier, known as
‘trolley’, motorcycle Centre of Gravity (CG) bar, CG stand and MechT TM Impactor. Various design factors have
been considered and factored in designing this crash test facility. Experimental tests and finite element analysis
are used to validate the design. A movable barrier is also specifically developed in enabling various impact
considerations in meeting market requirements via industrial applications. With the laboratory based crash test
facility, crashworthiness of the motorcycle could be determined in various impact specifications. Motorcycle crash
test could be optimized via various parameters with repetitive ability, hence saving costs and time while yielding
invaluable results.
Keywords: motorcycle, crash test, laboratory, movable barrier.
INTRODUCTION
Until few decades ago, full scale motorcycle crash test was carried out first time ever to investigate post crash
injury of motorcycle accidents. The crash objects include roadside guardrail and four-wheeled vehicles. A full
scale motorcycle crash test is deemed resources inefficient in terms of money spent, time consumed, huge space
requirements and also the variable factor of weather’s grace. In addition, another disadvantage of full scale crash
test is the difficulty in conducting parametric study. With the introduction of laboratory based facility, these
deficiencies could be easily overcome. Furthermore, with an introduction of a movable barrier, which is known as
trolley, it offers repeatability that could be suited to various crash objectives.
LITERATURE REVIEW
There have been numerous crash tests in the previous years that tests motorcycle’s crashworthiness. Several
research institutes have built a movable barrier, or also known as a trolley in conducting the tests. For example,
TNO Crash Safety Research has developed a trolley that provides forward momentum to the motorcycle at its
rear axis with support at the handle bar [1]. With the purpose of guiding the motorcycle and support for the dummy
prior to impact, the same methodology was further improvised and developed by DEKRA. A setup that mimics
TNO crash safety research, DEKRA’s trolley is designed to provide support to the motorcycle that is made to slide
on a rail in a predetermined speed. While in motion and prior to impact, the motorcycle is released to a crash
object which in this case is a guardrail [2]. In another test by Chawla et al., the kinetics of crash simulations is
matched with the full scale crash tests that were conducted by Japan Automobile Research Institute. In this test,
the motorcycle is guided with a trolley before it is released in a predetermined speed to impact with a passenger
car [3]. Within a similar method, A. B. Ibitoye et al., has developed a jig in his proposed full scale motorcycle crash
test to simulate motorcyclist’s kinematics during an impact. The jig consists of welded metal rectangular frames to
guide the motorcycle before it was released to crash with a W-Beam guardrail [4].
Research to date has focus more on full scale crash test versus that of a laboratory scale crash test while for
vehicle crash test; research is tended on four-wheeled vehicles than two-wheeled vehicles. In existing laboratory
based crash tests, sled test is widely used to evaluate dummy injuries in four-wheeled vehicle. In addition, fixed
and moving barriers were also developed for four-wheeled vehicle side impact crash tests. Movable deformable
barrier with pole side impact tests are being used as one of the standard certified test on passenger cars for side
impact safety analysis [5-6]. In addition, moving deformable barrier in accordance with National Highway Traffic
Safety Administration (NHTSA) specifications was also developed and is widely adapted in four-wheeled vehicle
side impact tests in the United States. In Europe, standard specifications are adopted in ECE R95 Dynamic Side
Impact Regulations. The wheel base for the trolley is at 3 metres with total mass of 950kg [7]. However, it is
important to note, with the variety of movable barriers being developed worldwide, few could be improvised for
laboratory based motorcycle crash tests as the developments are specifically commissioned for four-wheeled
vehicle crash tests.
METHODLOGY AND DESIGN CONSIDERATION
A number of drafts were drawn and considered before actual commissioning on the design of trolley. All the drafts
has been studied and improved based on design factors and test considerations. Finite Element Analysis is then
employed to determine further the actual representation of the trolley’s attachment, especially the W-beam
guardrail. This is an important process as it represents the actual soil-planted C-post in actual roadside, which is
1.12meter deep [8]. Upon satisfactory assessment, the confirmed design was then sent for fabrication. Once
done, the trolley undergoes few trial runs to validate its travelling velocity before it was incorporated for actual
motorcycle crash test. Figure 1 below shows the design flow chart.
Conceptual Design
Design Factors
Evaluation based on Finite Element Analysis
Test Considerations
Detailed Design
Fabrication
Validation
Figure 1: Design Flow Chart
Design factors and test considerations includes essential requirements for the motorcycle crash test and
constraints of the laboratory. The laboratory must be able to simulate full crash scenario and perform dynamic
testing which is not via conventional sled test. The motorcycle must be free to steer after release from guiding
system with the front wheel pointed straight to the direction of crash. The facility should also able to accommodate
dummy testing for investigative purposes post crash dummy kinematics. The front barrier, barrier-exchangeable
feature, should offer flexibility in material fixture as well as crash objects. It may also allow frontal or angle impact
considerations. These options invariably allow the most important factor which is repeatability.
FABRICATION AND FEATURES
The dimension for a generic trolley without front barrier is at 1.32m long, 1m wide and 0.6m in height. It consists
of 25.4mm by 25.4mm square bars that are welded together to form rectangular frames. The body frames are then
affixed with four wheels as shown in Figure 2 below.
One of the safety features would be the barrier-exchangeable ability. An attachable barrier is incorporated to
enable flexibility in material fixture for each selective crash test. This barrier-exchangeable feature enables either
a solid metal plate, which act as a ‘rigid wall’ or W-beam guardrail or deformable honeycomb structures, which act
as ‘passenger car bumper element’ to be attached to suit specific tests.
The second feature of the trolley would be the detachable steel mesh which is equipped on top of the trolley for
safety considerations. If the trolley is crashed with dummies or any other objects, those objects would be netted by
the steel mesh hence preventing any secondary impact to the crash object.
Figure 2: Trolley with four wheels
The third feature of the trolley would be the back plate. The trolley is designed with a rear affixed solid metal back
plate, as shown in Figure 3 below. The purpose of the rear affixed plate is to provide a counter impact zone from
the pendulum that in effect will project the whole trolley forward. Besides, the weight of the solid metal plate acts
to counter balance the weight of the W-beam guardrail at the front thus levelling out opposite lateral forces.
Back Plate
Long Bars
Figure 3: Back Plate and Adjustable Long Bar for Extra Load Requirement
Another feature of this trolley is the flexibility to accommodate various load configurations. Two long bars are
added to the front and back part of the trolley as shown in Figure 3 above. The height of two long bars can also be
adjusted depending on impact configurations. Different weights are then added horizontally to the front or to the
back of the trolley depending on crash test requirements. Loads that are added along the structure may shift the
centre gravity of the trolley. Figure 4 shows the loads or specially designed weights that are added to the trolley.
Figure 4: Weights are added to the Bar
A simple finite element analysis was performed to determine structural integrity on the trolley with the front
attachment, C-posts of W-beam guardrail. In the actual scenario, long C-posts are planted deep into the ground
along highways. During an impact, translational & rotational deformation is observed along the C-post. However,
in this trolley, by attaching the long C-post onto the trolley, structural strength is reduced due to the free end fitting
arrangement. Based on finite element analysis, a rigid block with similar width but height of 162mm needs to be
added to the upper portion of the long C-post, as shown in Figure 5 below.
Figure 5: Special Designed Rigid Block
The modified structure as re-analysed via finite element revealed that stress is still well within elastic region but
with the maximum deformation difference between the two C-post at less than 0.0002mm. This provides a high
correlation between a trolley’s C-post versus soil planted C-post. The results are shown in Figure 6 below. Full
views of W-beam guardrails are shown in Figure 7 below.
(a)
(b)
Figure 6(a): Deformation on Soil Planted C-Post;
(b): Deformation on Trolley’s C-Post Fitted with Rigid Block
(a)
(b)
Figure 7(a): Actual Soil Planted W-beam Guardrail Deformation;
(b): Trolley’s W-beam Guardrail Deformation Fitted with Rigid Block
Prior to establishing a trolley that can act as a movable barrier, a CG bar and CG stand are both developed. A long
steel bar, which is known as CG bar is placed beneath the seat of the motorcycle. It should be as near to the CG
location of the motorcycle as possible. The purpose of it is to hold the motorcycle from moving backward during an
impact, while it is free to steer, move upwards, downwards and forwards. Figure 8 below shows one side of CG stand
and CG bar.
Figure 8: CG stand and CG bar
Wong et al. had developed a patented machine known as MechTTM Impactor that is capable to undertake various
impact configurations [9]. Figure 9 showns the patented MechTTM Impactor. Trolley is placed beneath the
impactor’s arm. Motorcycle is placed at the CG stand. Trolley with back plate is then used to transfer the
impactor’s kinetic energy in mimicking a motorcycles’ impact energy. The setup is shown in Figure 10 below.
Figure 9:MechTTM Impactor [10]
(a)
(b)
Figure 10(a): Impactor’s arm is raised while the trolley is placed beneath the MechTTM Impactor;
(b): Laboratory Crash Test Facility setup with CG stand, CG bar and trolley.
As for trolley validation, the trolley was subjected to an impact force from the MechT impactor. Sandbags are placed
1.2metres away in front of trolley. Movement of the trolley are determined via fast speed camera. Velocity of the
trolley is then calculated accordingly. Figure 11 below shows a snapshot via fast speed camera. A solid metal plate is
attached as trolley’s frontal barrier.
Figure 11: Snapshot from fast speed camera while trolley moves..
Table1: Part of the trolley velocity
From Frame
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
24
To Frame
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
55
Average Speed
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.906 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.906 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.906 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.500 m/s
7.906 m/s
7.500 m/s
7.565 m/s
As the trolley moved prior to impacting the sandbag, parts of the velocity captured are listed in Table 1 above. Every
frame represents a 2 milliseconds interval. The moving trolley is captured with an average speed of 7.5m/s with 5%
variance, which is recorded at 7.906m/s for frame 31, 41, 48 and 53. This is an important setup consideration in view
of actual crash with motorcycle or any other crash object could take place within the 1.2metre distance from the
trolley. The crash object would experience the same impact velocity as shown in table above. Therefore the trolley
system exhibits no significant loss of energy as shown by the consistent speeds. In addition, there is no clearlydefined deceleration for the trolley. In other words, lost of energy due to friction prior to impact is minimal.
CONCLUSIONS
In concluding, the above trolley with attachable barrier is designed not only with ease of operation and
maintenance but also on the ability for customizable impact conditions with flexibility in varying impact loads. With
the development of CG stand on each side, CG bar and MechT Impactor, the laboratory based motorcycle crash
test facility is established. This facility provides wide usage adaptability. Parametric study can be easily conducted.
Not only can it act as the replacement for full crash test for motorcycle at laboratory level, it can also be instituted
as a test standard for motorcycle design guidelines. Various design factors and crashworthiness of the motorcycle
could be determined by having laboratory based motorcycle crash test facility. It is independent of weather forces
and efficient in terms of space consumed. Motorcycle manufacturers would be able to capitalise on the facility in
improving in house motorcycle parts or whole structural designs. In accident reconstructions, the facility would
greatly contribute in assessing impact velocity during accidents via its flexible crash configuration settings.
REFERENCES
[1] Nieboer, J.J., Wismans, J., Versmissen, A.C.M., and van Slagmaat, M.T.P., Kurawaki, I., and Ohara, N.
(1993) Motorcycle Crash Test Modelling. Proceedings of 37th Stapp Car Crash Conference, San Antonio, CA,
USA, 273-288, SAE paper 933133.
[2] Berg, F.A, Rucker, P., Gertner, M., Konig, J., Grzebieta, R., and Zou, R. (2005) Motorcycle Impact into
Roadside Barriers – Real-World Accident Studies, Crash Tests and Simulations carried out in Germany and
Australia, Preceedings of International Conference on Experimental Safety Vehicles, Munich, Germany, 1-12.
[3] Chawla, A., Mukherjee, S., Mohan, D.,Bose, D., Rawat, P.,Nakatani, T. and Sakurai, M. (2005) FE Simulations
of Motorcycle-Car Frontal Crashes, Validation and Observations, International Journal of Crashworthiness,
10:4,319-326.
[4] A.B.Ibitoye, A.M.S. Hamouda, S.V.Wong, R.S.Radin, (2006) Simulation of motorcyclist’s kinematics during
Impact with W-beam guardrail, Advances in Engineering Software 37, 56-61.
[5] Mizuno, K., Arai, Y. and Newland, C.A. (2004) Compartment Strength and its evaluation in car crashes,
International Journal of Crashworthiness, 9:5, 547-557.
[6] Wang D., Dong. G., Zhang. J., Huang. S, (2006) Car Side Structure Crashworthiness in Pole and Moving
Deformable Barrier Aside Impacts”. TsingHua Science and Technology, ISSN 1007-0214 13/15 pp725-730,
Volume 11, Number 6.
[7] United Nations Economic Commission of Europe, Transport Division, (1995) Vehicle Regulations Added to the
1958 Agreement (Regs 81-100) Concerning the Adoption of Uniform Conditions of Approval and Reciprocal
Recognition of Approval For Motor Vehicle Equipment and Parts, ECE Regulations 95, Uniform Provisions
Concerning The Approval Of Vehicles With Regard To The Protection Of The Occupants In The Event Of A
Lateral Collision, p37
[8] Jabatan Kerja Raya (JKR) – Malaysia Public Works (1993) Manual on Design Guidelines of Longitudinal
Traffic Barrier Arahan Teknik (Jalan) 1/85.
[9] S.V. Wong, A.M.S. Hamouda, M.M. Megat Ahmad, R.S. Radin Umar, K.S.Tan, (2006) MechT 524 CI-75 with
capacity of 25J, 50J and 75J, commercialized impact tester of Malaysian Patent PI20024307 & United State
Patent 2004103713
[10] K.S.Tan, S.V.Wong, R.S.Radin Umar, A.M.S.Hamouda, N.K.Gupta, ‘An experimental study of deformation
behaviour of motorcycle front wheel-tyre assembly under frontal impact loading’, International Journal of
Impact Engineering 32 (2006) 1554–1572.