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SIMON is a new vehicle dynamic simulation model. Applications for SIMON include single- and multi-unit vehicle handling simulation in severe limit maneuvers (including rollovers) and 3-dimensional environments. Applications also include vehicle-to-vehicle and vehicle-to-barrier collisions. This paper provides the technical background for the SIMON engineering model. The 3-dimensional equations of motion used by the model are presented and explained in detail. The calculations for suspension, tire, collision, aerodynamic and inter-vehicle connection forces and moments are also developed. The integration of features available in the HVE Simulation Environment, such as DyMESH, the Driver Model, Brake Designer and Steer Degree of Freedom, is also explained. Finally, assumptions and limitations of the model are presented.

This paper describes the use of 3-D technologies for reconstructing and simulating motor vehicle accidents involving humans (occupants and pedestrians) and vehicles (passenger cars, pickups, vans, multi-purpose vehicles, on-highway trucks and vehicle-trailers). All examples involve three-dimensional environments, including road crowns, hills, curbs and embankments - any geometrical feature resulting in three-dimensional motion. Various reconstruction and simulation models are illustrated. The features and limitations of each model are addressed. Issues involving data requirements, preparation of 3-D models and presentation techniques (numeric, graphic and video animation) are also explored.

A new three-dimensional collision simulation algorithm, called DyMESH (Dynamic MEchanical SHell) was recently introduced.[1]* This paper presents a validation of DyMESH for vehicle vs. barrier collisions. The derivation of the three-dimensional force vs. crush relationship was described previously.[1] Here the application of three-dimensional force vs. crush curves using the outlined methodology is shown to be effective. Nonlinear force versus crush relationships are introduced for use in DyMESH. Included are numerous DyMESH collision simulations of several types of vehicles (e.g., light and heavy passenger car and sport utility) compared directly with experimental collision test results from various types of barrier tests (e.g., full frontal, angled frontal, and offset frontal). The focus here is not on the vehicle’s change in velocity, but on the acceleration vs. time history.

Motor vehicle safety researchers have used the Phase 4 vehicle simulation model for several years. Because of its popularity and ability to simulate the 3-dimensional dynamics of commercial vehicles (large trucks and truck tractors towing up to three trailers), the Phase 4 model was ported to the HVE simulation platform. The resulting model is called EDVDS (Engineering Dynamics Vehicle Dynamics Simulator). This paper describes the procedures used in porting Phase 4 to the HVE platform. As a result of several assumptions made during the development of Phase 4, the port to EDVDS required substantial changes. The most significant modeling difference is the removal of the small angle assumption, allowing researchers to study complete vehicle rollover. Also significant is EDVDS’s use of HVE’s Get Surface Info () function, allowing the vehicles’ tires to travel over any 3-D terrain of arbitrary complexity. These and other changes in the model are described in the paper.

SIMON is a new 3-dimensional vehicle dynamic simulation model. The capabilities of the model include non-linear handling maneuvers and collision simulation for one or more vehicles. As a new model, SIMON must be validated by comparison against actual handling and collision experiments. This paper provided that comparison. Included in the validation were lane-change maneuvers, alternate ramp traversals, limit maneuvers with combined braking and steering, vehicle-to-vehicle crash tests and articulated vehicle handling tests. Comparison against other models were included. No metric was provided for handling test comparisons. However, statistical analysis of the collision test results revealed the average path range error was 6.2 to 14.8 percent. The average heading error was -4.7 to 0.7 percent. Delta-V error was -1.6 to 7.5 percent. VEHICLE SIMULATION has many uses in the vehicle design and safety industries.