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DYNAMIC
TESTING |
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Sled Impact Test -
Q'Straint -
QS 9910
Frontal Impact of QRT by Q'Straint Deluxe Retractor System
Wheelchair Tiedown and Occupant Restraint System
Loaded by a SAE/ISO Surrogate Wheelchair
and Midsize-Male ATD
Submitted to:
Q'Straint USA
5553 Ravenswood Road
Building 104
Fort Lauderdale, Florida 33312
The University of Michigan
Transportation Research Institute
2901 Baxter Road
Ann Arbor, Michigan 48109
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ACKNOWLEDGMENT AND DATA USE RESTRICTION Funds for this test were
provided by Q'Straint of Fort Lauderdale, Florida. 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 Pentium-II workstation. 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
The ISO/SAE surrogate wheelchair was placed on the sled platform facing forward
and secured using the four-point, strap-type QRT Deluxe Retractor System by
Q'Straint. For this test, the retractors were bolted directly to the sled plate
and no anchor plates or fittings were used. The front tiedown straps were hooked
to the securement points provided at the front of the surrogate wheelchair
immediately beneath the front edges of the occupant seating area. The rear
tiedown straps were hooked to the securement points provided on the back of the
seat frame just below the junction of the seat and seatback frame support
members.
The wheelchair was loaded with a midsize-male ATD that was restrained by an
independent three-point belt restraint system. The pelvic belt anchored to the
rear tiedown retractor assemblies just above the webbing spools. The pelvic belt
was tightened to fit snugly over the ATD pelvic region. The tension in the
shoulder belt was controlled by a retractor system and was allowed to operate as
in the vehicle environment. The shoulder belt anchor point was positioned to
achieve the shoulder belt angles and belt geometry suggested by SAE J2249.
The test was conducted using 48-kph (30-mph) and 20-g average impact conditions
to determine the frontal-impact response of the wheelchair tiedown and occupant
restraint system. The following table provides further details about the test
equipment and setup.
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SUMMARY OF TEST SETUP AND PRE-TEST MEASUREMENTS
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 9910Novembers, 1999
ISO/SAE surrogate wheelchair 85 kg (187 lb)
QRT Deluxe Retractor System by Q'Straint
Model Q-8100-A1
SN# QRTA1246
Lap and Shoulder Combination by Q'Straint
Midsize-male ATD @ 76.4 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) |
1316 mm (51.8 in)
432 mm (17.0 in)
46 degrees
0 degrees
381 mm (15.0 in)
495 mm (19.5 in)
805 mm (31.7 in)
40 degrees
22 degrees
584 mm (23.0 in) |
OCCUPANT RESTRAINT
D-ring 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 |
305 mm (12.0 in)
178 mm (7.0 in)
1270 mm (50.0 in)
318 mm (12.5 in)
47 degrees
50 degrees, measured at ATD torso
30 degrees, measured above ATD shoulder |
ATD POSITIONING
Shoulder height above sled platform
H-point height above sled platform |
1100 mm (43.3 in)
566 mm (22.3 in) |
WHEELCHAIR
Weight
Wheelbase
Seatback angle wrt vertical
Seatback height (without headrest)
Seatpan angle wrt horizontal
Seat surface height from floor @ SB junction
Seatpan length |
85.0 kg (187.0 lb)
546 mm (21.5 in)
9 degree
559 mm (22.0 in)
5 degrees
470mm (18.5 in)
432 mm (17.0 in) |
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TEST RESULTS
The QRT Deluxe Retractor System sustained impact loading intact and effectively
secured the SAE/ISO surrogate wheelchair. Both the wheelchair and ATD remained
on the sled platform and the ATD was in an upright position at the end of the
test. The maximum forward excursion of point P on the wheelchair was limited to
171 which is below the maximum recommended excursion of 200 mm. After the test,
the ATD and the wheelchair could be released and removed from the tiedown and
occupant restraint system without the use of tools.
The ATD was effectively restrained from forward excursion by the Q'Straint
pelvic and shoulder belt system and was limited to approximately 512 mm of head
excursion and 223 mm of knee excursion, which are both below the recommended
excursion limits of 650 mm and 375 mm, respectively. The ATD did not submarine
under the pelvic belt during impact, and the pelvic belt was on the ATD pelvis
at an angle of 45 degrees relative to horizontal at the end of the test. The
ratio of the ATD's knee excursion to the wheelchair point P excursion is 1.3,
which is above the minimum recommended ratio of 1.1.The results of this test
indicate that this wheelchair tiedown and occupant restraint system meet the
requirements for dynamic strength specified in part 6.2 of SAE recommended
practice J2249 "Wheelchair Tiedown and Occupant Restraint Systems for Use in
Motor Vehicles " and parts 6.2. land 6.2.2 of draft standard ISO 10542-1
(version 11/99). The following tables provide a summary of the test results and
compliance with relevant standard sections. |
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SUMMARY OF 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 9910
48.8 kph (30.3 mph)
20.0 g
23.7 g
31.7 ms
58.4 ms
80.8 ms |
ATD MEASUREMENTS
Peak resultant head acceleration
Peak resultant chest acceleration
Head Injury Criterion
Maximum forward head excursion#134;
Maximum forward knee excursion#134;#134;
Average post-test H-pt ht above sled platform |
81 g
44 g
748
512 mm (20.2 in)
223 mm (8.8 in)
572 mm (22.5 in) |
TIEDOWN LOADS
Peak left-rear tiedown force
Peak right-rear tiedown force |
18965 N (4264 lb)
18617 N (4186 lb) |
BELT LOADS AND PELVIC BELT ANGLE
Peak right pelvic-belt load
Peak shoulder-belt load
Post-test pelvic restraint angle |
8877 N (1996 lb)
7469 N (1679 lb)
45 degrees |
WHEELCHAIR MEASUREMENTS #134;#134;
Maximum forward wheelchair excursion
at Point P*
Maximum forward excursion of
front-wheel hub
Maximum forward excursion of
rear-wheel hub |
171 mm (6.7 in)
180 mm (7.1 in)
175 mm (6.9 in) |
† 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.
*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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SUMMARY OF TIEDOWN FRONTAL IMPACT PERFORMANCE SLED TEST QS 9910 |
| Requirement |
Result |
SAE J2249
(ISO 10542
ver 1 1/99)
Clause |
Description |
Observed Performance |
Pass/Fail |
6.2a
(6.2.1 a&b) |
Retain ATD in WC and on test sledwith WC upright. |
ATD in WC and on test sledwith WC upright. |
Pass |
6.2b
(6.2.1 g&h) |
WTORS cannot show visible signs of structural failure that is not anticipated by its design. |
No structural failure of WTORS and no sharp edges post-test. |
Pass |
6.2c
(6.2.1 c) |
WTORS cannot detach from anchorages or securement points. |
No tiedowns released from securement points or anchorages. |
Pass |
6.2d
(6.2.2 a) |
Forward excursion of Point P<200 mm |
171 mm |
Pass |
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Forward knee excursion <375 mm |
223 mm |
Pass |
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Forward head excursion <650 mm |
512 mm |
Pass |
6.2e
(6.2.2 b) |
Ratio of ATD knee excursion to Point P excursion must exceed 1.1. |
Ratio of ATD knee excursion to Point P = 1.3. |
Pass |
6.2f
(6.2.1 e&f) |
Allow removal of ATD and WC without the use of tools. |
No tools required for disassembly. |
Pass |
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