Sled test systems have been used by the automotive and aerospace industries for decades as a tool for developing safety systems. Sled testing allows engineers to reproduce the dynamic conditions of a full-scale crash event in a controlled environment and at a fraction of the cost of a crash test. Sled systems provide repeatable and reliable impact conditions around which automotive seats, seat belts, and supplemental restraints can be developed. Typically such tests are conducted to represent a simple frontal collision. However, even very complex crash events, such as those created by impacts involving two moving vehicles, can be modeled by a sled system. Exponent has developed a process to determine the pulse shape, magnitude, and Principal Direction of Force (PDOF) of a sled pulse when presented with such crash test data.
Exponent conducted a research program to evaluate the capabilities of a sled in replicating the impact pulse and the PDOF of a complex two-moving vehicle crash test. The test program evaluated a sled's capability of not only replicating the conditions of a crash event that produced very little rotational motion but also the conditions of a crash event that involved significant rotational motion. The process that was developed as a result of the program was validated by comparison of the results from a complex full-scale crash test, and was published with the Society of Automotive Engineers(SAE 2007-01-0711).