Evaluation of energy absorbing pliers underride guards for rear and side of large trucks

by Bodapati, Venkata Kiran

Accidents with heavy vehicles, especially in underride crashes, be it rear, side or frontal, are responsible for thousands of deaths all over the world. In many cases, these tragedies are consequences of not having effective underride guards mounted to the rear, side and front of the heavy vehicles. Lack of effective underride guards brings less compatibility making heavy vehicles more aggressive on roads. Several designs have been designed for energy absorbing underride guards. A new underride guard is developed based on the mechanical principle of simple pliers tool was conceived by Louis Otto Faber Schmutzler, SAE BRAZIL 1995. This research work describes nature of underrides, the design and analysis of two new guards for rear and side, vehicle behavior at different speeds and prevention of passenger compartment intrusion. With the advance in computer simulations, full finite element validated vehicle models are being analyzed for different impact scenarios. The main purpose of building the simulation models is to reduce the real time tests which are associated with significant cost. In this thesis, two new guards for rear and side are modeled using MSC-Patran and the performance of the guard in preventing passenger compartment intrusion is analyzed using LS- Dyna. A zero passenger compartment intrusion is achieved with the employment of the newly designed underride guards for rear and side of the trucks. The newly designed guard models are validated using FMVSS 223/224 regulations. The results are in good correlation with the experimental data for rear and the passenger compartment intrusions are reduced in the case of rear and side underride. The performance of the guard is studied at 30, 40 and 50 miles per hour. v