Vehicle Subframe Effects on Frontal Collision

Ensuring passenger safety is a crucial consideration in designing vehicles. Forces that are transmitted to the passenger compartment, particularly during collisions, can jeopardize the safety of the passengers. Hence, minimizing forces in the vehicle body and chassis plays a crucial role in enhancing passenger safety. Many vehicles with a unibody chassis feature a subframe as a supplementary element. The primary contribution of the subframes to the performance of the vehicle is the reduction of noise and vibration. However, subframes can also improve factors such as suspension stiffness, vehicle handling, and vehicle stability. This paper examines the effect of the presence and design modifications to the subframe on vehicle body forces. To achieve this, five subframe designs with different dimensions and materials are modeled. They are then installed on a full-scale vehicle model, and frontal collisions with a barrier and a pole are simulated. The vehicle body forces during various cases of frontal collisions are studied by measuring the acceleration and acceleration magnitude of three points on the B-pillar in the time domain and frequency domains. The results indicate that a subframe can reduce vehicle body forces, with the subframe's design influencing the extent of this effect.