飞机起落架回转地面载荷特性研究

计算地面回转工况下的回转力矩和回转机轮接地点地面载荷对起落架结构设计有重要意义,以共轴双轮式起落架和四轮车架式起落架为研究对象,通过假设轮胎与地面接触面为椭圆印痕,并应用极坐标二重积分的计算方法,推导出回转力矩计算公式和轮胎接地点地面载荷计算公式,并结合算例将传统方法和本文方法的计算结果进行对比.结果表明:回转力矩随着轮胎压缩量的增加而增加;传统方法得出的回转力矩偏小;对于共轴双轮和四轮车架式起落架,轮胎接地点处的扭矩占回转力矩的比例很小,同时接地点处存在较大的航向、侧向力.

Characteristic Research of Pivot Ground Torque for Aircraft Landing Gear

Pivot torque and tire contact point load calculation under pivot load case had important significance for landing gear structure design. Twin wheels and twin tandem landing gears were taken as research objects. Contact patch between tire and ground was assumed to be elliptic impression. Double integral under polar coordinates was applied. Calculation expressions of pivot load and contact point ground load were deduced. Combined with calculation cases some useful results were gained: Pivot torque was increasing as tire deflection increased; Pivot torque calculated by reference method was small; Contact point torque was much less than pivot torque, and contact point had great longitudinal as well as lateral force with regard to twin wheels and twin tandem landing gear.