Full-scale vehicle crash testing is often used as an engineering tool to reproduce the dynamic conditions of real-world accidents. The complex and destructive nature of conducting these crash tests makes them very expensive. Often times engineering analysis requires multiple tests wherein occupant motion or vehicle component performance comparisons are made when subject to specific dynamic conditions. For these situations, sled testing becomes the preferred evaluation method.
Sled testing allows engineers to reproduce the dynamic conditions of a full-scale crash test in a controlled environment at a fraction of the cost. A particular advantage of sled testing is that only a single vehicle is consumed. Typically the occupant compartment of the vehicle, referred to as a vehicle buck, is mounted to the test sled. The sled and buck can then be subjected to accelerations representative of a particular crash environment. This controlled acceleration is commonly referred to as a sled pulse, and can be modeled after accelerometer data collected from actual crash testing. In this way, even complex crash events, such as those created by impacts involving two moving vehicles, can be replicated with sled tests.
This paper establishes a process to determine the pulse shape, pulse magnitude, and Principal Direction of Force (PDOF) of a sled pulse when presented with crash test data. The discussion includes conditions wherein the crash test vehicle experiences very little rotational motion in the plane of the ground, or yaw, as well as those conditions that involve significant yaw motion, causing the PDOF to vary substantially during the impact event. The process is validated by conducting a sled test using the parameters derived from the crash test data.