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DYNAMIC
TESTING |
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Sled Impact Test - Q'STRAINT - QS 9602
Frontal Impact of ISO/SAE-Modified Surrogate Wheelchair
Secured by the Q'Straint On-Track System, Oriented Fore/aft,
with Midsize-Male ATD Restrained by Q'Straint Three-Point Restraint
Submitted to:
Q'Straint
16-100 Sheldon Drive
Cambridge, Ontario N1R 7S7 Canada
The University of Michigan
Transportation Research Institute
Ann Arbor, Michigan 48109
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ACKNOWLEDGMENT AND DATA USE RESTRICTION
Funds for this test were provided by Q'Straint of Cambridge, Ontario.
These test results are advisory in nature and do not constitute endorsement,
certification, or approval of the products. At no time shall the name of The
University of Michigan or the University of Michigan Transportation Research
Institute (UMTRI) be used in the advertisement or marketing of the products
tested.
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TEST METHODS
This impact test was conducted on the UMTRI impact sled. The sled operates on
the rebound principle, achieving a desired velocity by reversing its direction
of motion during the impact event. The sled crash pulse is trapezoidal in shape
and is reported as an average deceleration level in G. The sled velocity is
monitored immediately before and after impact.
Data generated during the test were multiplexed and recorded on the direct
record channels of a Honeywell Model 9600 magnetic tape recorder and
simultaneously digitized live using a 486 personal computer. All signals were
filtered to the requirements of SAE J-211.
The photo-instrumentation consisted of high-speed (1000-frames/sec) 16-mm
motion-picture cameras for side, overhead, and rear views of the impact event. A
Polaroid® graph-check camera was also used to provide a quick-look sequenced
photograph of the impact event. The transducer data and the high-speed test
films were simultaneously marked by a timing pulse generated at ten-millisecond
intervals. A strobe flash recorded the onset of impact. |
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TEST SETUP
GENERAL TEST INFORMATION
Test number
Test date
Wheelchair type
Wheelchair tiedown
Occupant restraint
Anthropomorphic Test Dummy (ATD)
Wheelchair orientation
Sled platform
Desired impact velocity ( V)
Desired average sled deceleration |
QS 9602
May 1, 1996
ISO (SAE modified) surrogate wheelchair
Q'Straint on-track four-point
strap-type tiedown, oriented fore/aft
Q'Straint integrated three-point pelvic and
shoulder belt
Midsize male @ 76 kg (168 lb)
Forward facing
Rigid steel plate
48 kph (30 mph)
20 G |
WHEELCHAIR TIEDOWN
Front-to-rear anchor-point distance
Rear tiedowns
Lateral distance between anchor points
Angle wrt horizontal
Angle wrt to wheelchair center plane
Anchor point to rear-wheel hub
Length (anchor point to securement point)
Front tiedowns
Lateral distance between anchor points
Angle wrt horizontal
Angle wrt to wheelchair center plane
Length (anchor point to securement point) |
1270 mm (50.0 in)
356 mm (14.0 in)
42 degrees
0 degrees
325 mm (12.8 in)
445 mm (17.5 in)
610 mm (24.0 in)
35 degrees
20 degrees
605 mm (23.8 in) |
OCCUPANT RESTRAINT
Shoulder belt upper anchor point location
Behind ATD shoulder
Above ATD shoulder
Above sled platform
Left of wheelchair centerline
Angle of pelvic belt wrt to horizontal
Angle of shoulder belt
Projected frontal view wrt horizontal
Projected lateral view wrt horizontal |
279 mm (11.0 in)
191 mm (7.5 in)
1298 mm (51.1 in)
381 mm (15.0 in)
52 degrees
51 degrees, measured at ATD torso
32 degrees, measured above ATD shoulder |
ATD POSITIONING
Shoulder height above sled platform
H-point height above sled platform |
1080 mm (42.5 in)
559 mm (22.0 in) |
WHEELCHAIR
Weight
Center of gravity location
Above sled platform
Forward of rear-wheel axle
Wheelbase
Seatback angle wrt vertical
Seatback height
Seatpan angle wrt horizontal
Seat surface height from floor @ SB junction
Seatpan length |
84.5 kg (186 lb)
295 mm (11.6 in)
165 mm (6.5 in)
528 mm (20.8 in)
10 degrees
556 mm (21.9 in)
4 degrees
464 mm (18.3 in)
445 mm (17.5 in) |
TEST SETUP (continued)
The ISO (SAE modified) surrogate wheelchair was placed on the sled platform
facing forward and secured using the Q'Straint on-track four-point,
strap-type tiedown system. The anchor track was mounted to the sled platform
so that the long axis of each of the anchor plates was parallel to the
centerline of the wheelchair (i.e., the long axis ran fore/aft). The front-tiedown
straps were hooked to the wheelchair at the forward securement points
located below the front edge of the seating surface on each side. The rear-tiedown
straps were hooked to the securement points provided at the rear of the
wheelchair directly above the rear axles.
The wheelchair was loaded with a midsize-male ATD that was restrained by the
Q'Straint pelvic and shoulder belt system. The pelvic belt was tightened to
fit snugly over the ATD's pelvic region. The shoulder restraint was adjusted
so that a 75-mm block could be inserted between the ATD's chest and the
belt. The upper shoulder belt anchor point was chosen to optimize the
shoulder belt fit on the ATD and is not necessarily representative of a
particular vehicle anchoring geometry. The entire assembly was tested at 48
kph (30 mph) and 20-G average crash conditions to determine the impact
response of the prototype four-point tiedown system. |
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TEST RESULTS
GENERAL TEST INFORMATION
Test number
Actual impact velocity (V)
Actual average sled deceleration level
Actual peak sled deceleration level
Total time of deceleration over 20 G
Total time of deceleration over 15 G
Deceleration pulse duration |
QS 9602
46.3 kph (28.8 mph)
21.3 G
24.9 G
38.1 ms
60.8 ms
76.5 ms |
ATD MEASUREMENTS
Peak resultant head deceleration
Peak resultant chest deceleration
Head Injury Criterion
Maximum forward head excursion†
Maximum forward knee excursion † †
Average post-test H-pt ht above sled platform |
57 G
57 G
525
353 mm (13.9 in)
274 mm (10.8 in)
559 mm (22.0 in), 0% change |
TIEDOWN LOADS*
Peak left-rear tiedown force
Peak right-rear tiedown force |
14087 N (3167 lb)
15048 N (3383 lb) |
BELT LOADS
Peak shoulder belt load
Peak left pelvic-belt load
Peak right pelvic-belt load |
10263 N (2307 lb)
10201 N (2293 lb)
Not measured |
WHEELCHAIR MEASUREMENTS††
Maximum forward wheelchair excursion
at Point P**
Maximum forward excursion of
front-wheel hub
Maximum forward excursion of
rear-wheel hub
Peak longitudinal wheelchair acceleration |
76 mm (3.0 in)
107 mm (4.2 in)
99 mm (3.9 in)
33 G, measured on right side of the wheelchair
frame at the CG height and fore/aft position |
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† The head excursion is reported as the total forward change in position of the leading edge of the head, measured at the initial position prior to impact and at the time of maximum forward head travel.
†† Excursions reported are the total horizontal change in the position of the affixed targets relative to the sled platform from just prior to impact to the time of maximum forward excursion.
*Forces reported for the tiedown straps are for one loop of a double strap system and represent approximately half the total tiedown load.
**Point Pisa seating reference point located 50 mm above and 50 mm in front of the junction of the seatback and seat cushion planes. |
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TEST RESULTS (continued)
The Q'Straint on-track four-point, strap-type tiedown system successfully
restrained the surrogate wheelchair during impact. Both the wheelchair and ATD
were in an upright position at the completion of the test, and the ATD remained
in a seated posture. The maximum forward excursion of point P on the wheelchair
was 76 mm, which is below the recommended upper excursion limit of 200 mm.
The ATD was effectively restrained by the Q'Straint 3-point belt system during
the test. The ATD was limited to 353 mm of head excursion and 274 mm of knee
excursion, which are both below the recommended upper excursion limits of 650 mm
and 375 mm, respectively. The ratio of knee excursion to wheelchair excursion is
3.6, which is above the minimum recommended ratio of 1.1. None of the wheelchair
tiedown or occupant restraint components showed evidence of fragmentation or
separation. The wheelchair tiedown and occupant restraint system remained
attached at all anchorage and securement points. |
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