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Forensic evidence within a crash vehicle's occupant compartment as well as the occupant injuries may provide important validation tools for the accident reconstructionist, particularly to corroborate the principal direction of force (PDOF) on the occupant. The objective of this study was to evaluate forensic evidence of dynamic loading found on the seat belt webbing, latch plate, D-ring, and any other associated restraint components as a function of frontal impact angle in a series of sled tests utilizing 95th percentile male, 5th percentile female, and 6 year old Hybrid III ATDs. A late 1990s full size SUV was converted to a sled buck for testing. The test series included impact angles from 0 degrees to 60 degrees in 15 degree increments. The tests were conducted at approximately 35 kph (22 mph) on a rebound style sled. Post-impact, the seat belt systems were removed from the sled, labeled and archived for subsequent detailed analysis.

The purpose of this paper is to assist the investigator examining motor vehicle crashes involving child restraint devices (CRD). During a crash, if the CRD has been installed properly, it should provide protection to the child occupant. When it does not, the crash investigator must examine the CRD, belts and vehicle for the reason protection was not provided. A crash investigator should be able to determine use, non-use, or improper use of the CRD. Case studies presented will help an investigator determine items such as use or nonuse, improper use, CRD positioning, and belt routing. Forensic evidence examined on the CRD and the vehicle belts are presented from case investigations, sled tests, and crash tests.

The Federal Motor Vehicle Safety Standards (FMVSS) require rear seat, lap/shoulder belts to “fit” Hybrid III dummies ranging in size from a 6 year old child (H3-6C) to a 95th-percentile-male (H3-95M). No dynamic performance FMVSS, however, exist for rear seat belt systems. Variations in the three-dimensional “fit” of the same lap-shoulder belt positioned around these extreme dummy sizes suggest a possible difference in performance. The purpose of this study was to assess the performance of two production lap-shoulder belt designs in a large SUV buck on a rebound sled using instrumented H3-6C, 5th-percentile-female (H3-5F) and H3-95M dummies. Sled velocities were approximately 35 kph. Test instrumentation included: lap and shoulder belt load transducers, triaxial accelerometers at the center of gravity of the head, triaxial accelerometers and a deflection gauge in the chest, and six-axis force (and moment) transducers in the neck of the dummy.

Catastrophic head and spinal injuries have been reported to older children, properly restrained in the back seats of motor vehicles. The interaction of small stature occupants in contemporary, rear restraint systems has not yet been reported in controlled frontal oblique sled test conditions. Such data is fundamental to understanding potential mechanisms of injuries and effective countermeasures. The purpose of this study was three fold: (1) to conduct a series of controlled sled tests to determine the critical angle at which torso roll-out from the shoulder belt occurs in 6 year old Hybrid III (H3-6C) and 5th percentile female Hybrid III (H3-5F) dummies, (2) to compare dummy injury measures to the standard Injury Assessment Reference Values (IARVs) as a function of impact angle, and (3) to assess the influence of belt pretensioners and anchorage geometry as countermeasures to submarining and torso rollout dummy kinematics.

Oblique crashes to the vehicle front corner may not be characteristic of either frontal or side impacts. This research evaluated occupant response in oblique crashes for a driver, rear adult passenger, and a rear child passenger. Occupant responses and injury potential were evaluated for seating positions as either a far-or near-side occupant. Two crash tests were conducted with a subcompact car. The vehicle’s longitudinal axis was oriented 45 degrees to the direction of travel on a moving platform and pulled into a wall at 56 km/h. Dummies utilized for the seating positions were an adult dummy (50th-percentile-HIII and THOR-Alpha) for the front-left (driver) position, 5th-percentile-female-HIII for the right-rear position, and a 3-year-old HIII for the left-rear position.