Abstract
Research and/or Engineering Questions/Objective
From 2003 IIHS research, smalloverlap crash recorded high fatality in real road traffic. So IIHS created new crash performance 64kph 25% overlapping with rigid pole. The structural rating is very severe because only the side structure of the car resist from the crash force. Without reinforcing structure it's hard to achieve good in the structure. But in case of frontal wheel separation case, the structural performance becomes beneficial because the wheel does not push the structure after separation like space-empty and wheel separation accompanies the vehicle’s lateral movement. Less overlapping helps vehicle to avoid the rigid pole easily.
Methodology
To achieve the wheel separation, A & B points should be separated in early time. If the knuckle links are broken also, this helps the whole wheel separation during the smalloverlap crash. Also we should consider the development price considering ride handling, turning radius and driving feeling with NVH and durability requirement. To get the all satisfaction, component tests for wheel separation would be very useful. In this paper, we designed new component test fixture through full car phenomena observation, full car CAE correlation and each major parameter setting-up. Technical characteristics: 1) brake system determines system stroke. 2) shock tower attachment is controlled by pyrotechnic device. 3) Hinge pillar honeycomb has density and geometry like real structure deformation 4) X/Y coordinate adjustable hinge pillar location 5) Adjustable subframe and wheel location Y 6) Adjustable barrier location Y 7) Subframe cut and attached with same front and rear mount coordinates.
Results
Through this component test, with CAE correlated 45kph speed, we got very close F-d curve, separation timing and deformation shape of lower arm in LF (Sonata 16MY) and alloy material lower arm car like LF HEV. Also we are planning to run the tests soon with AD (Elantra 17MY) for effective wheel separating lower arm solution.
Limitations of this study
The small gap (1~2ms) of wheel separation time has occurred between component test and vehicle test. And the hinge pillar honeycomb costs some budget to proceed this test. Also, experience is need to run this test is difficult one for the novice.
What does the paper offer that is new in the field including in comparison to other work by the authors?
Among the known component tests of wheel separation, this 1/4 scale of car, one-wheel component test with only chassis parts is quite new one.
Conclusions
New component test of wheel separation with low cost have been developed. The correlated speed is 45kph and many characteristics like F-d curve, separation timing and deformation shape of steel and aluminum lower arm was very close.
Key Words : wheel separation, smalloverlap, component test, lower arm