Rollover simulation and crashworthiness analysis of trucks

This paper presents a computer-based technique for the dynamic analysis of multibody systems undergoing large motion and structural deformations. As a specific example, this formulation is applied to the rollover simulation of a truck (multibody system) to determine the deformation of its safety rollbar cage (structure). For a multibody system, the equations of motion are generated in a systematic form from the data that describe the system. The data contain such information as the inertia characteristics of each body in the system, the connectivity between and the forces acting on the bodies. For a vehicle these equations describe the motion of the chassis, the suspension systems, the wheels, the steering system, and other components. The suspension springs and shock absorbers may have linear or nonlinear characteristics. Tire deformation and the corresponding interaction with the ground are also incorporated into the equations. The cab or the safety rollbar cage is modeled by the finite element method. The model may contain beam, plate, or other types of finite elements. The material property of the structure is assumed to be linear for small structural deformations. However, in severe rollover or crash situations the deformation is no longer elastic, therefore, elasto-plastic material characteristics must be considered. The equations of motion for the multibody system and for the structure are then combined to form a complete set of equations of motion. For a vehicle, a numerical solution of these equations results in a dynamic response in a rollover or other situations.