THOR dummy chest deflection response in oblique and lateral far-side sled tests

Abstract

Objective: The focus of this study is side impact. Though occupant injury assessment and protection in nearside impacts has received considerable attention and safety standards have been promulgated, field studies show that a majority of far-side occupant injuries are focused on the head and thorax. The 50th percentile male Test Device for Human Occupant Restraint (THOR) has been used in oblique and lateral far-side impact sled tests, and regional body accelerations and forces and moments recorded by load cells have been previously reported. The aim of this study is to evaluate the chestband-based deflection responses from these tests. Methods: The 3-point belt-restrained 50th percentile male THOR dummy was seated upright in a buck consisting of a rigid flat seat, simulated center console, dashboard, far-side side door structure, and armrest. It was designed to conduct pure lateral and oblique impacts. The center console, dashboard, simulated door structure, and armrest were covered with energy-absorbing materials. A center-mounted airbag was mounted to the right side of the seat. Two 59-gage chestbands were routed on the circumference of the thorax, with the upper and lower chestbands at the level of the third and sixth ribs, respectively, following the rib geometry. Oblique and pure lateral far-side impact tests with and without airbags were conducted at 8.3 m/s. Maximum chest deflections were computed by processing temporal contours using custom software and 3 methods: Procedures paralleling human cadaver studies, using the actual anchor point location and actual alignment of the InfraRed Telescoping Rods for the Assessment of Chest Compression (IR-TRACC) in the dummy on each aspect-that is, right or left,-and using the same anchor location of the internal sensor but determining the location of the peak chest deflection on the contour confined to the aspect of the sensor; these were termed the SD, ID, and TD metrics, respectively. Results: All deformation contours at the upper and lower thorax levels and associated peak deflections are given for all tests. Briefly, the ID metrics were the lowest in magnitude for both pure lateral and oblique modes, regardless of the presence or absence of an airbag. This was followed by the TD metric, and the SD metric produced the greatest deflections. Conclusion:The chestbands provide a unique opportunity to compute peak deflections that parallel current IR-TRACC-type deflections and allow computation of peak deflections independent of the initial point of attachment to the rib. The differing locations of the peak deflection vectors along the rib contours for different test conditions suggest that a priori attachment is less effective. Further, varying magnitudes of the differences between ID and TD metrics underscore the difficulty in extrapolating ID outputs under different conditions: Pure lateral versus oblique, airbag presence, and thoracic levels. Deflection measurements should, therefore, not be limited to an instrument that can only track from a fixed point. For impr...

A Correction Method Based on the Simulation and Experiment of Side Sled Collision

“…Sled testing, also known as carriage testing, is primarily utilized to substitute certain aspects of whole vehicle collision tests for the development of vehicle restraint systems. Due to the ability to conduct multiple tests on the same vehicle structure without the concern of damaging the overall vehicle structure during testing, coupled with the short preparation time required for testing, sled testing can effectively reduce the development cycle and cost of restraint systems [15], [16], [17], [18].…”

Analysis of characteristics about far-side occupant’s chest injury during oblique side impact

“…Yoganandan et al 11 studied the reliability of parameters related to the chest injury of THOR dummy in the far-side impact and pointed out that the chest deflection of THOR dummy would fluctuate with different sensor positions. Therefore, the measurement of deflection should not be limited to fixed measurement points, but should be combined with other methods to evaluate the chest injury of the far-side occupant.…”

“…The two dummies had high consistency with the cadaver experiment in simulating the head movement trajectory. Yoganandan et al 11 pointed out that the rib geometry of the WorldSID dummy was regular and the ribcage was more simplified. The THOR dummy could better reflect the real characteristics of the human chest.…”

Research on characteristics of occupant’s chest responses in oblique impact

“…It is concluded that the risk of serious injury in oblique impact was significantly higher than that in full-frontal impact. Yoganandan et al 6 verified the influence of side curtain airbags on the chest deflection during an oblique impact and found it can be used to reduce the injury outcomes. Guerrero et al 7 compared the kinematic differences between the Test Human Occupant Restraint (THOR) dummy and the Hybrid III dummy during an oblique impact and found that the THOR dummy can better reflect the chest injuries.…”