The aim of this paper is to investigate and to enhance crashworthiness of vehicle-to-vehicle full and offset frontal collisions using two smart front-end structures. Two different types of smart front-end structures, fixed and extendable, have been proposed to support the function of the existing vehicle. The work carried out in this paper includes developing and analyzing mathematical models of vehicle-to-vehicle in full and offset frontal collision events for the two types of smart front-end structures. In this paper, the dynamic responses of the crash events are obtained with the aid of an analytical approach using Incremental Harmonic Balance Method (IHBM). 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, it is shown that the mathematical models are convenient and can be used in an effective way to give a quick insight of crash accidents.