THOR-50M thoracic deflections: Preliminary dynamic assessment in frontal barrier crash tests

The research objective is to assess the potential for injury reduction by implementing the THOR-50M as the primary device for vehicle restraint system design.

Data for this analysis was gathered from NHTSA crash testing. Data were collected from two series of frontal rigid barrier tests using a THOR-50M in the driver position. Twenty tests with the THOR-50M in the driver position were conducted with 16 different make/model/generation vehicles. Matched-pair data from the same make and model/platform vehicle were collected from the US NCAP testing which used HIII-50M ATDs in the driver position, for model year vehicles between 2013 to 2023. Thoracic deflection data were analyzed for matched-pair tests and trends over model year. Lap and shoulder belt loads, pelvis excursion, and femur forces were examined to determine how they influenced thoracic deflections in each ATD. Additionally, US NCAP and EuroNCAP test data were examined for ATD thoracic deflection trends.

Data from frontal crash testing indicated minor, if any, deviations in HIII-50M thoracic deflections on average for vehicle model years between 2013 and 2023. HIII-50M deflections ranged from 18 to 26 mm, and averaged 22 mm. In contrast, the THOR-50M deflections were more scattered among vehicles tested. The THOR-50M resultant maximum thoracic deflections ranged from 38 to 66 mm, and averaged 46 mm.

Vehicle design related to thoracic injury mitigation has leveled off possibly due to the HIII-50M's limited thoracic deflection measurement instrumentation and vehicle design optimization for the HIII ATDs. Injury reduction would involve designing improved restraint systems beyond the HIII-50M capabilities and require the THOR-50M capabilities to advance safety systems. Designing and tuning restraint systems with the THOR-50M, which has thoracic measurement improvements over the HIII-50M may result in thoracic deflection reductions and an associated potential thoracic injury reduction.