Resonance and energy-absorption capability of polyurethane foam in high-shock launching for scout-robot

For solving the high-overload problem existing during launching the scout-robot, the polyurethane foam was used as cushion material to reduce the overloads endured by the scout-robot. The energy-absorption capability of the polyurethane foam in the high-shock launching was discussed. Based on the structure of the robot protection shell and the properties of the cushion material, a mathematical model was established for the base-excited system with single degree of freedom. And the natural frequency of this system was analyzed as well as its amplification coefficient. An interior ballistics measurement system was developed to measure the acceleration curves of the scout-robot with and without cushion. The experimental results show that the system can produce resonance to make its acceleration increase when the natural frequency of the system is close to the excitation frequency of the launching device. And the natural frequency of the cushion system can be changed by adjusting the system parameters to reduce the amplification coefficient to less than 1 and thus the cushion system can avoid resonance.