A Flight Load Test Method for Helicopter Rotor Blade

Abstract

This paper studies a flight load test method for helicopter blade, including the structural force of helicopter blade, strain gauge bridge modification, load calibration method and the establishment of load calibration equation in the typical maneuvers. First, blade structure of the helicopter was analyzed and the strain gauges were pasted in the load profile which were considered to be important positions to analysis the flight safe of helicopter. Second, Load calibration equations were obtained by ground calibration test, which would be used to convert the strain time curve to the load time curve. The helicopter flighted in different maneuvers, such as hovering, horizontal flight and climbing. At the same time, flight parameters were recorded, such as helicopter altitude, pitch angle, roll angle and yaw Angle. The flight parameters can be used to analysis the flight conditions. Then the blade flight load in different flight maneuvers was analyzed. The result was that the time-domain waveform was neat, good periodicity, strong regularity, no hybrid interference and jump point. It was illustrated that the blade load test flight data were accurate and reliable, which met the accuracy requirements of Engineering. The blade load data obtained through different flight maneuvers can be used to structural modification, fatigue analysis and blade design.