EDSMAC

Name	EDSMAC (Engineering Dynamics Simulation Model of Automobile Collisions)
Description	EDSMAC is an analysis of single or two vehicle accidents. It is based on the Calspan Simulation Model of Automobile Collisions (SMAC) and includes refinements and enhancements provided by Engineering Dynamics Corporation. EDSMAC is a simulation; it uses a set of assumed initial conditions provided by the user (vehicle positions and velocities at impact) and determines the outcome (vehicle rest positions and impact damage). EDSMAC is a 3-degree of freedome (yaw plane) analysis; suspension effects are ignored. The collision is analyzed by establishing a force balance between the vehicles as they crush (impact). The force vectors act upon the vehicle CG's until separation occurs. The conditions of separation provide the initial conditions for a trajectory simulation which analyzed the impact-to-rest phase. Accident investigators can use EDSMAC to determine the conditions of impact (usually impact velocity and velocity change). The procedure involves an initial estimate of the impact velocity and velocity change). The procedure involves an initial estimate of the conditions of impact made by the user of supplied by EDCRASH; this is followed by a series of user-made adjustments to the initial conditions until the final results match the physical evidence (rest positions and vehicle damage) found at the accident site.
Input	Title, Simulation Time, Impact Separation and Trajectory Time Steps, Minimum Velocities, Impact Positions (x, y, psi) and Velocities (forward, lateral angular), Vehicle Dimensions (CG location, track width overall length and width), Inertial Properties (mass, yaw moment), Cornering Stiffness for Each Tire, Braking and Steering Tables, Rear Axle Steer Angles, Tire/Road Friction, Terrain boundary, Collision Force Vector Interval and Increment, Inter-vehicle Friction Parameters and Crush Stiffness, Coefficients of Restitution. By selection AUTOLOAD, the user can automatically load all of the required input data for a given class vehicle. Various parameters can be changed at the user's option prior to execution.
Output	Vehicle Path Variables (CG position, velocity, acceleration, sideslip, tire tracks), Collision Deformation Classifications, Damage Profile, Velocity Changes, Echo of Input Data.
Graphics	Vehicle Trajectories (various formats include continuous, variable time increment, freeze, and movie), both with simultaneous display of key data; Vehicle Damage Profiles; Plotting of output data vs. time.
Other Features	Input session logic checks data as it is entered; the user may change any data prior to execution; the user may request a detailed explanation of the required input, including answer format and sample answer; rerun and file-saving options. Output session displays data in a complete or abbreviated format; routes the results to the screen or printer; extensive warning messages and validity checking; provides input for EDHIS; file-saving option.