Effects of seat pan and pelvis angles on the occupant response in a reclined position during a frontal crash

Current highly automated vehicle concepts include reclined seat layouts that could allow occupants to relax during the drive. The main objective of this study was to investigate the effects of seat pan and pelvis angles on the kinematics and injury risk of a reclined occupant by numerical simulation of a frontal sled test. The occupant, represented by a detailed 50th percentile male human body model, was positioned on a semi-rigid seat. Three seat pan angles (5, 15, and 25 degrees from the horizontal) were used, all with a seatback angle of 40 degrees from the vertical. Three pelvis angles (60, 70, and 80 degrees from the vertical), representing a nominal and two relaxed sitting positions, were used for each seat pan angle. The model was restrained using a pre-inflated airbag and a three-point seatbelt equipped with a pretensioner and a load limiter before being subjected to two frontal crash pulses. Both model kinematic response and predicted injury risk were affected by the seat pan and the pelvis angles in a reclined seatback position. Submarining occurrence and injury risk increased with lower seat pan angle, higher pelvis angle, and acceleration pulse severity. In some cases (in particular for a 15 degrees seat pan), a small variation in seat pan or pelvis angle resulted in large differences in terms of kinematics and predicted injury. This study highlights the potential effects of the seat pan and pelvis angles for reclined occupant protection. These parameters should be assessed experimentally with volunteers to determine which combinations are most likely to be adopted for comfort and with post mortem human surrogates to confirm their significance during impact and to provide data for model validation. The sled and restraint models used in this study are provided under an open-source license to facilitate further comparisons.

Secondary Impact Protection for Locomotive Engineers – Improved Airbag Design

Under the locomotive cab occupant protection research program sponsored by the Federal Railroad Administration (FRA), Sharma & Associates, Inc. (SA) developed a Secondary Impact Protection System (SIPS) for locomotive engineers. The system uses a large, automotive-style, passenger airbag in combination with a deformable knee bolster to provide the level of protection needed for the locomotive engineer, without compromising the normal operating environment and egress. A prior version of the system [1] was prototyped and tested in a dynamic sled test with a 23g crash pulse and was shown to meet most limiting human injury criteria defined in the Department of Transportation (DOT)’s Federal Motor Vehicle Safety Standards (FMVSS 208) [2] for the head, chest, neck, and femur. The system also showed marginal performance for the chest injury index and indicated potential for an improved airbag design to fully meet all requirements. In the current study, simulations with an optimized airbag and higher capacity inflator system showed that SIPS can provide excellent occupant protection for an unbelted locomotive occupant in a frontal crash. Sled testing of SIPS confirmed the performance, and the system successfully met all eleven (11) criteria of the FMVSS 208 standard [2]. The shape and position of the airbag module and its attachments to the desk were generally the same as those presented in previous research. The key changes that helped meet all criteria were the higher capacity inflators, knee bolster system brackets moved forward, thicker knee plate, higher volume airbag and additional vents.

Composite materials in automotive industry: A review

Composite materials have found extensive use among many industries including automotive. Vehicles are supposed to be lightweight, have low emission and energy consumption to provide some environmental protection while having appropriate stiffness and strength to assure occupant protection. These requirements can be met with the use of composite materials. Although composites have been present in the industry for decades, their use in the automotive sector is moderately new, which requires development in design and manufacturing processes, testing, and recycling - this paper indicates the details by which the automotive industry differs from others. Principal recycling methods, related legislation, and where recycling products are used are described. Specific uses of composite materials that show a high level of innovativeness are indicated - hybrid and natural composites, structural batteries, and high-performance vehicles.

Child restraints for cars in low and middle-income countries

When used correctly, modern child restraints provide exceptional protection for children in car crashes. Most vehicles sold in high-income countries (HIC) have top tether anchorages and/or ISOFIX lower anchorages that are intended to reduce the incidence of misuse, in addition to improving occupant protection. Most vehicles in LMIC do not have these features and many do not have seat belts in rear seats or have inferior lap-only seat belts in these seats. Children in these vehicles are at much greater risk of severe injury in the event of a crash. This paper examines ways to safely restrain children in these ill-equipped vehicles, mainly through retrofitting child restraint anchorages and seat belts.