Vol 76 No 2 76202

Abstract

This work aims to design a drop tower impact rig to examine the effectiveness of suspension seats for small high-speed passenger crafts and to evaluate whether the designed suspension seat can effectively mitigate the slamming impact on passengers and lower the risk of injuries. A drop tower was fabricated, and drop tests were conducted at different drop heights to simulate base impact acceleration between the range of 3g to 7g. Acceleration data captured using accelerometers were low pass filtered accordingly, and the seat effectiveness and safety were analyzed using the Dynamic Response Index (DRI). The seat’s stiffness was experimentally and theoretically analyzed using Hooke’s Law, and damping values were analyzed using the logarithmic decrement method. The results revealed that DRI values, limited to 18, can only be attained with deck acceleration of less than 6.73g. The tested suspension seat reduced the impact severity by 54 %. This impact mitigation is achievable with an underdamped system of average stiffness and damping rates of 64.8 kN/m and 211 Ns/m, respectively. The research has successfully proved that the fabricated drop tower could simulate the base impact acceleration of desired slamming impact acceleration according to drop heights and that the designed suspension seat can mitigate the severity of the slamming impact effectively.