Dynamic modeling and analysis of vehicle's smart front-end structure for frontal collision improvement

In this research, two types of smart front-end structure are proposed to improve vehicle crashworthiness. The first type consists of two non-extendable hydraulic cylinders parallel to the longitudinal members. The second type consists of two extendable hydraulic cylinders integrated with the front-end structure. The literature review shows that little has been done for the development of simplified models for automotive crash problems in general, and smart front-end structures in particular. The development of such models is desirable for use in the initial concept design stage of automotive structures. The work carried out in this research includes developing and analyzing mathematical models of vehicle-to-vehicle and vehicle-to-barrier in different frontal collision events. In these models, vehicle components are modeled by lumped masses and nonlinear springs. Moreover, the hydraulic cylinders are represented by nonlinear dampers elements. Two types of nonlinearity forms, piecewise and cubic, are used to define the characteristics of both nonlinear springs and dampers. In this research, the dynamic responses of the crash events are obtained with the aid of analytical and numerical approaches. Moreover, the intrusion injury and occupant deceleration are used for interpreting the results. It is demonstrated from simulation results that significant improvements to both intrusion and deceleration injuries are obtained using the smart front-end structures. Furthermore, the vehicle compatibility and the crash severity have been significantly minimized.