EDCRASH (Engineering Dynamics Corporation Reconstruction of Accident Speeds on the Highway)
EDCRASH is a reconstruction analysis of single- or two-vehicle accidents, including collision. Based on the CRASH model developed at Calspan and extended by NHTSA, EDCRASH also includes several enhancements developed by EDC, including hard spots on the vehicle exterior and an extensive set of run-time diagnostics that help confirm valid results.
EDCRASH primary purpose is to determine impact speed and delta-V (a measure of impact severity) based on accident site and vehicle damage measurements. EDCRASH is also well-suited for collisions with immovable barriers, such as bridge abutments and large trees.
EDCRASH has been validated using the RICSAC collision experiments, a set of 12 well-instrumented staged collisions. Several validation studies have been published in the technical literature.
EDCRASH is a 2-D, 3 degree-of freedom (X,Y,PSI) analysis for each vehicle. For oblique impacts, EDCRASH uses the conservation of linear momentum; for collinear collisions, vehicle damage is used in conjunction with crush stiffness coefficients derived from barrier crash testing. The impact-to-rest phase is analyzed using energy methods and a modified Marquard method allowing for the effects of vehicle rotation and curved trajectories. The impact-to-rest phase may also be confirmed by a trajectory simulation.