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Conceptually, a steering wheel mounted air cushion is inflated before the upper torso of the driver significantly interacts with the cushion. However, this might not be the case for some seating postures or vehicle crash environments which could cause the driver to significantly interact with an inflating cushion. These experiments utilized several environments to study the interaction between an inflating driver air cushion and mechanical surrogates. In these laboratory environments, the measured responses of mechanical surrogates increased with diminishing distance between the surrogate's sternum and the steering wheel mounted air cushion.

This paper covers the development of the General Motors Energy Absorbing Steering System beginning with the work of the early crash injury pioneers Hugh DeHaven and Colonel John P. Stapp through developments and introduction of the General Motors energy absorbing steering system in 1966. evaluations of crash performance of the system, and further improvement in protective function of the steering assembly. The contributions of GM Research Laboratories are highlighted, including its safety research program. Safety Car, Invertube, the biomechanic projects at Wayne State University, and the thoracic and abdominal tolerance studies that lead to the development of the Viscous Injury Criterion and self-aligning steering wheel.

A relationship between the risk of significant thoracic injury (AIS ≥ 3) and Hybrid III dummy sternal deflection for shoulder belt loading is developed. This relationship is based on an analysis of the Association Peugeot-Renault accident data of 386 occupants who were restrained by three-point belt systems that used a shoulder belt with a force-limiting element. For 342 of these occupants, the magnitude of the shoulder belt force could be estimated with various degrees of certainty from the amount of force-limiting band ripping. Hyge sled tests were conducted with a Hybrid III dummy to reproduce the various degrees of band tearing. The resulting Hybrid III sternal deflections were correlated to the frequencies of AIS ≥ 3 thoracic injury observed for similar band tearing in the field accident data. This analysis indicates that for shoulder belt loading a Hybrid III sternal deflection of 50 mm corresponds to a 40 to 50% risk of an AIS ≥ 3 thoracic injury.

The study was directed toward improving our understanding how postcrash column compression and steering wheel deformation relate to the driver interaction with an energy absorbing steering system during automotive collisions. Frontal sled tests conducted at 19–37 km/h investigated the Part 572 antropomorphic dummy interaction with a ball-sleeve column steering assembly over a range of column angles and surrogate postures. Neither column compression nor steering wheel deformation correlated with the mechanical severity of the test surrogate interaction with the steering system. The steering wheel deformed before the column compressed and the degree of wheel deformation strongly depended on the surrogate load distribution, the steering wheel being an important energy absorbing element.

Sled tests were conducted to investigate the dynamics of a Part 572 dummy as a sfunction of the belt restraint configuration and impact direction. The tests involved a 35 km/h velocity change and 10 g deceleration. An “opened” fixture, free of intervening surfaces, was oriented from frontal (0°), through oblique (±30°,±45°, ±60°), to full lateral (±90°). Restraint by only a lap belt resulted in the dummy's upper body rotating about the lap belt and continuing in the direction of sled deceleration. Restraint by a lap-shoulder belt greatly reduced upper-body displacement. However, the displacement and body loading were strongly dependent on the direction of deceleration, i.e., the orientation of the belt relative to the impact direction. When the belted shoulder was opposite the impact (0° to +90°), the belt retained the upper body for impact angles of 0° to 45°.

Measurement of chest compression is vital to properly assessing injury risk for restraint systems. It directly relates chest loading to the risk of serious or fatal compression injury for the vital organs protected by the rib cage. Other measures of loading such as spinal acceleration or total restraint load do not separate how much of the force is applied to the rib cage, shoulders, or lumbar and cervical spines. Hybrid III chest compression is biofidelic for blunt impact of the sternum, but is “stiff” for belt loading. In this study, an analysis was conducted of two published crash reconstruction studies involving belted occupants. This provides a basis for comparing occupant injury risks with Hybrid III chest compression in similar exposures. Results from both data sources were similar and indicate that belt loading resulting in 40 mm Hybrid III chest compression represents a 20-25% risk of an AIS≥3 thoracic injury.