民机起落架机构破冰动力学仿真分析方法

Dynamic Simulation Analysis Method for Icebreaking of landing Gear Mechanism of Civil Aircraft

民机在遭遇降雪、降霜、冻雨等极端气候条件时,运动机构有可能附着冰层,当积冰达到一定程度,便可能影响到机构的正常运动。为研究起落架机构在上述极端气候条件下的环境适应能力,基于ADAMS建立民机起落架多体动力学模型,考虑重力、冰层黏滞力、摩擦力对机构运动的影响,仿真分析了不同温度、不同冰型下的起落架机构的驱动力矩。研究发现,常温无冰工况下,起落架收放动作受重力影响最大;当在环境温度-25℃左右形成冻结冰时,起落架所需破冰驱动力矩最大;起落架发生结冰(冻结冰或撞击冰),破除冰层所需驱动力矩数值的分散性很大;起落架严重积冰时,仅靠驱动无法实现破冰,需进行除冰作业。本文建立起落架多工况破冰动力学模型的建模流程具有很好的移植性,可推广到其他机构的破冰动力学仿真。

When civil aircraft encounter extreme weather conditions such as snow,frost,freezing rain,etc.,the locomotion mechanism may be attached to ice.When the ice accumulation reaches a certain extent,the normal movement of the mechanism may be affected.In order to study the adaptability of the landing gear mechanism in the above extreme climate conditions,a multi-body dynamics model of civil aircraft landing gear was established based on ADAMS platform.Considering the effects of gravity,ice viscosity and friction force on the movement of the landing gear,the driving torque of the landing gear mechanism under different temperatures and different ice types was simulated and analyzed.The results show that gravity has the greatest effect on landing gear retraction under normal temperature and no ice condition.When frozen ice is formed at ambient temperature of-25℃,the landing gear requires the maximum ice-breaking driving torque.When the landing gear freezes(freezing ice or impinging ice),the driving torque values required to break the ice are highly distributed.In the case of serious ice accumulation in the landing gear,ice breaking cannot be achieved by driving alone,and ice removal must be performed.In this paper,the modeling process of multi-condition icebreaking dynamics model of landing gear has good portability and can be extended to the icebreaking dynamics simulation of other mechanisms.