A Moving Deformable Barrier with Dynamic Force and Deflection Spatial Measurement Capabilities for Full Scale Tests

This paper describes the design and development of an advanced instrumentation Moving Deformable Barrier (MDB) for use in research crash testing to address vehicle aggressitivity and compatability issues. The instrumented MDB design is an adaptation of the current Federal Motor Vehicle Safety Standard (FMVSS No. 214) MDB design and duplicates as closely as possible its physical and dynamic specifications. Forty-four equally spaced low weight triaxial load cells are placed behind the main body of the aluminum honeycomb structure. In addition, an equal number of string potentiometers are placed in the rear of the cart to measure the honeycomb crush. The triaxial load cells were specially designed to measure forces in both the longitudinal and shear directions. During the initial design stage, the number of load cells, their weight, placement, type, durability and measuring capacity were considered. The location and retraction properties of the displacement transducers were also considered. Since the advanced MDB was initially designed with the current cart design, the center of gravity and mass moments of inertia were tuned as closely as possible to the current MDB design through small changes to the cart's design and string potentiometer placement. The stability of the new design was verified through dynamic tests of the MDB impacting a rigid wall under both perpendicular and oblique impacts. Force-versus-deflection characteristics were measured both statically and dynamically for a variety of impact conditions. These were used to upgrade the aluminum honeycomb material codes of the MDB finite element model developed for simulation studies. Comparisons of the dummy and vehicle responses in FMVSS No. 214 tests of a passenger car showed good correlation between current and instrumented designs. Lastly, future research areas are recommended based on this design.