Sled Impact Facility
The UMTRI impact sled is a 450-kilogram, 2-meter-square platform that travels on an 18-meter track into a pneumatic, rebound-type decelerator to simulate typical crash velocities and decelerations. The sled is accelerated by a pneumatically-powered ram from one end of the track. The impact takes place at the opposite end, where a pneumatic spring controls the duration and magnitude of the impact event, and digital high-speed video cameras record the kinematics of vehicle components and instrumented crash dummies. The test buck, including seat, restraint system, and actual or simulated vehicle components, are bolted to the sled frame. The sled can be equipped with a standard reusable bench seat for child-restraint testing as required by FMVSS 213, with a passenger-side-airbag deployable buck for evaluating airbag interaction with an infant dummy in rear-facing child restraints, or with a modified body buck from an actual vehicle. UMTRI also has the equipment needed to evaluate wheelchairs and wheelchair tiedown and occupant restraint systems according to ISO and ANSI standards for crash protection. A variety of instrumented test dummies, including a six-month infant dummy, three-year-old and six-year-old child dummies, and small-female and mid-sized male adult dummies, enable evaluation of restraint systems and vehicle components for a range of occupant sizes. Transducer signals from dummy instrumentation, sled deceleration, velocity transducers, and seatbelt load cells are collected by an on-board TDAS data acquisition system and are transmitted to a dedicated laptop post-test for immediate review of data. A software package developed at UMTRI provides digital filtering and analysis of data using standard signal processing criteria specified in SAE J211, as required by Federal Motor Vehicle Safety Standards, or using other criteria specified and selected by the test engineer or sponsor. Data are routinely analyzed to compute peak dummy resultant head and chest accelerations, peak belt loads, and head injury criteria (HIC) values. Also, analysis and display programs can be tailored for a particular user to produce force-deflection plots or other needed output. Pre- and post-test digital images, test videos, and test data are uploaded to a secure website so sponsors can quickly review their test data remotely. Analysis software is routinely used to determine dummy and seat kinematics from test videos.