民用飞机顺气流襟翼机构故障工况动力学仿真研究

Dynamics Simulation Research on Fault Conditions of deflecting to airflow flap mechanism of Civil Aircraft

摘要:

民机顺气流襟翼一般由空间复杂多铰机构驱动，按照适航条款CCAR25.671的要求需开展典型故障下的机构特性研究。首先构建了复杂多铰空间机构运动数字样机，采用多点约束RBE3单元将刚性多铰机构交点关联至柔性襟翼本体，建立了襟翼机构刚柔耦合动力学模型；在巡航、起飞、着陆三种卡位气动载荷工况下，利用调节铰链运动副摩擦系数和设置单侧驱动失效的方法分别模拟了铰链卡滞和操纵系统单侧失效两种典型故障；最后，分析了故障工况下襟翼驱动力矩和铰链点载荷变化规律。结果表明：铰链卡死时，内侧扭力管力矩在0.8s会达到1.57×108 N·mm，内侧驱动连杆耳片发生拉伸破坏；内侧驱动失效时，外侧机构驱动力矩增大了7.5倍，摇臂铰链点最大径向载荷最大增大13.5倍。在实际中应重点关注该类襟翼外侧摇臂中关节轴承的径向承载能力，避免外侧机构出现单独操纵的情况，同时需要对整个驱动系统增加扭矩保护。

Abstract:

The deflecting to airflow flap of civil aircraft are generally driven by complex multi-hinge mechanisms in space. According to the requirements of airworthiness clause CCAR25.671, it is necessary to carry out research on mechanism characteristics under typical faults.Firstly, a digital prototype of complex multi-hinge space mechanism is constructed. The multi-point constraint RBE3 element is used to associate the intersection point of the rigid multi-hinge mechanism to the flexible flap body, and the rigid-flexible coupling dynamic model of the flap mechanism is established.Under the three aerodynamic load conditions of cruise, take-off and landing, two typical faults, hinge jamming and single-point failure of the control system, were simulated by adjusting the friction coefficient of the hinge kinematic pair and setting the single-side drive failure.Finally, the variation law of flap driving moment and hinge point load under fault conditions is analyzed. The results show that: when the hinge is jamming,the torque of the inner mechanism will reach 1.57×108 N·mm in 0.8s, and the inner driving link ear piece will be stretched and damaged. When the inner mechanism fails, the driving torque of the outer mechanism increases by 7.5 times, and the maximum radial load of the rocker arm hinge point increases by a maximum of 13.5 times.In practice, we should focus on the radial bearing capacity of the joint bearing in the outer rocker arm of this type of flap to avoid the situation of independent manipulation of the outer mechanism, and at the same time, it is necessary to add torque protection to the entire drive system.