Synthesis and Optimization of Mechanical Networks with Inerters in Landing Gear for Improved Landing Performance and Vibration Control at Touchdown Considering Airframe Flexibility

Using a flexible airframe model, this study optimizes various single-port (two-terminal) passive mechanical networks that consist of an arrangement of springs, dampers, and inerters to minimize passenger discomfort and peak forces applied to the aircraft. The performance of the mechanical networks is compared to a baseline oleo-pneumatic shock absorber. First, the importance of including airframe flexibility effects was demonstrated as the peak landing gear loads, the loading regime, and the frequency response of the structure were altered when compared to the equivalent rigid model. Next, eight candidate layouts were optimized, then the observations from this exercise were used to synthesize a mechanical network with a desired frequency response. All considered mechanical networks demonstrated the ability to control the frequency content of the input loading, thus resulting in a reduction in accelerations and an improvement in all comfort parameters used in this study over the oleo-pneumatic baseline.