A recovery mechanism for flap system of large aircraft with actuator failure

High-lift devices of transport aircraft reshape the wing in order to increase the lift of the aircraft during certain portions of flight. In order to increase its reliability, large transport aircrafts usually install the inter connection strut (ICS) as security devices. However, there are very limited publications on how to design the ICS, and how it works. There is a strong motivation for modeling and simulating the behavior of high-lift devices with ICS once failure happens and resulting design parameters. In this study, based on rigid-flexible coupling multi-body modeling technique, and dynamic response analysis of flap system under normal operation and failure state, a design method of ICS is proposed and the key parameters, that is, freely moving range and the mean crushing load of the energy absorber, are identified. The mitigation effect of ICS for actuator failure of flap system is clarified by analyzing the dynamic response of flap system with ICS. The results show that the ICS can reduce the peak driving torque of drive strut by 45.3%, and the unexpected rotation of the flap decreases by 66.2% after actuator failure happened.