Search Results

Accelerator-type sled systems have been very useful to the automotive industry for many years. These systems have allowed engineers to effectively evaluate a safety component in a frontal crash environment without having to conduct a full-scale crash test. While accelerator-type sleds are an excellent tool for frontal crashworthiness development, the energy required to simulate a side impact or lateral pole impact test is just a small fraction of the total capacity of the system. In light of this, a project was undertaken to develop a system which incorporated many features of the current accelerator-type sled system, but was designed to simulate non-frontal crash test cases. This paper describes the development and test applications for the new sled system. The operating theory and general design is similar to current accelerator-type sled systems, although the new system has been scaled down significantly.

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.

A comprehensive strategy for applying quasi-static and dynamic tests in the development of automobile side impact protection systems is presented. The approach is geared towards providing an understanding of how vehicle components relate to occupant protection as measured by the FMVSS 214 dynamic side impact test. These test methods are viewed as being complimentary, rather than competitive, tools to be employed in the overall strategy. The approach begins with obtaining detailed data from an FMVSS 214 dynamic test. Additional instrumentation is required so that the results of the test can be used to form the basis for setting conditions for subsequent quasi-static and dynamic tests. The Composite Test Procedure (CTP) is an integral part of the process. As described here, the CTP can be conducted under three different methods; three step procedure, continuous computer control, and continuous manual control.

The Eurosid-1 dummy was subjected to a series of lateral and oblique pendulum impacts to study the anomalous “flat-top” thorax deflection versus time-histories observed in full-scale vehicle tests. The standard Eurosid-1, as well as two different modified versions of the dummy, were impacted at 6 different angles from -15 to +20 degrees (0 degrees is pure lateral) in the horizontal plane. The flat-top deflections were observed in the tests with the standard Eurosid-1, while one of the modified versions reduced the flat-top considerably. Full scale vehicle tests with the standard and modified Eurosid-1 suggest similar reductions. A second series of tests was conducted on the modified Eurosid-1 to investigate the effect of door surface friction on the shoulder rotation and the chest deflection. The data suggested that increasing the friction on the door surface impeded shoulder rotation and ultimately reduced the chest deflection in the Eurosid-1.

Side impact crashworthiness development presents a unique challenge to auto safety engineers. One fundamental issue is how to evaluate side impact air bags with a component test that realistically simulates the kinematics of a full scale side impact crash test. This paper presents a test methodology that can be used to evaluate side impact air bags utilizing an accelerator-type sled typically used for frontal impact simulation. The approach uses a “two carriage” system, whereas the struck door and vehicle acceleration profiles are simulated. These acceleration responses are matched through a series of sled variables including thrust column setting, metering pin shape and an on-board pneumatic cylinder which controls the relative response between the two carriages.

Over the recent years, tests have been developed which will result in higher levels of protection afforded to pedestrians involved in vehicle impacts. These requirements will result in improved vehicles, which are designed to be safer and less harmful to pedestrians. The requirements include a series of impact tests into the front end of a vehicle with a variety of instrumented forms including an adult headform, a child headform, as well as an upper legform and a complete legform. Although the requirements have not been finalized, it is expected that they are to become part of the European homologation test series soon. Automobile manufacturers that sell cars in Europe are beginning to incorporate the proposed regulations into new car designs.