Design and Analysis of the Bio-Inspired Rear Under-Run Protection Devices for Heavy Truck

The rear under-run protection devices (RUPD) could prevent the entry of a small vehicle under rear side of the heavy truck, and decrease the injuries and deaths when the accident occurs. In this paper, a new concept of the mechanical design of heavy truck RUPD is presented based on the bio-inspired method, by analyzing the structure of a kind of sheep horn, which has good capacities of energy absorption and structural strength. Firstly, the space geometry characteristic of the sheep horn in macroscopic view was analyzed. Then the research was focused on its mechanical property, and the microstructure of the horn sample was observed by the scanning electron microscope (SEM). Based on the test results, the structure characteristic and force condition of the horn were discussed. A new RUPD structure was designed in both macro and micro levels using bionic principle. The superior mechanics performance of the sheep horn was transplanted into the new RUPD. Finally, the finite element model for the new RUPD, which is inspired from the sheep horn, was established and analyzed. Simulation results showed that the protection device had better strength characteristic and could effectively protect car occupants in under-run accidents. Therefore, with the remarkable strength performance and simple structure, the bionic RUPD shows the promise for practical application.