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The occupant retention performance of laminated and tempered side glazing during rollover collisions is analyzed. A brief history of automotive glazing is given, including a discussion of current technology. A summary of glazing failure mechanisms is provided, along with the results of impact and quasi-static pushout testing of undamaged commercial and prototype door windows. The investigation shows that supported laminated side glazing gives performance comparable to windshield glazing and can effect both primary and secondary containment of occupants. Results of documented unplanned rollover collisions and staged rollover tests are presented in support of the conclusions drawn.

Occupant motion in a vehicle rollover accident is a function of many factors. Some important ones are vehicle kinematics, position of the occupant in the vehicle, occupant size, ground topology and restraint usage. The far side belted occupants are more vulnerable than the near side occupants in a rollover accident as they have more energy as a result of their trailing and higher side of the vehicle. This outcome is attributable to the inadequate safety performance of the conventional single loop; B-pillar mounted D-ring restraints. Roof crush tends to displace the vehicle's B-pillar, resulting in D-Ring displacement which causes slack in the lap portion of the restraint. This slack enables centrifugal loads to move the far side occupant further away from the vehicle's instantaneous point of rotation. In this scenario, the presence of any ejection portal can result in an occupant becoming partially or fully ejected.

Child safety in the back seat during a rear-impact chiefly depends on how well the survival space is maintained at their location. Collapsing front seatback pose a foreseeable hazard as it intrudes into the survival space of the child on the backseat. Furthermore, the condition gets worse in the presence of a structural intrusion from the rear that tends to push the occupant further closer to the backward collapsing seatbacks. This paper reports two real-world rear impact collisions resulting severe to fatal injuries to the child occupant seating behind the driver. Each collision shows the dangers of seatback collapse into the survival space of the child. Furthermore, the paper demonstrates safety through design concept by employing seats with strong seatback design resisting collapse into the survival space of the child.

Seatback and head restraints are the primary restraining devices in rear-impact collisions. The seatback failures expose front seat occupants to dive deep into the rear compartment survival space. Furthermore, it allows the occupants to get in a position with lower spinal tolerance to the impact direction. This paper employs sled tests to demonstrate the dangers of seatback failures in severe rear impact by allowing the occupants to orient their spine in its lowest tolerance zone to the impact direction. Furthermore, the sled test shows the potential of head pocketing phenomena and torso augmentation producing compressive cervical spine loading enough to cause first-order neck buckling. Finally, the results of collapsing seatback dynamics are compared to the strong seatback performance by conducting a similar test with a strong ABTS seatback.