直升机六力素识别

本文介绍载荷识别技术。提出了“应变传递矩阵法”载荷识别的基础理论、不同性质载荷的识别方法和公式。叙述了直升机飞行载荷-六力素识别的三个主要阶段:传递矩阵的确定（地面标定）、结构响应实测（空中飞行试验）、载荷计算（六力素计算）。文中还就随机载荷识别进行了讨论。

SIX-FORCE-FACTOR IDENTIFICATION OF HELICOPTERS

Load identifications are to calculate applied loads by using motion equations and measured data of motion parameters of a system. They are inverse problems of solving differential equations. The first part of this paper presents the basic theory of the frequency response function method in load identifications. The calculation formulas areH（w）F（w）=X（w） andSx（w） = H（w）Sf（w）H*T（w）which are suitable for different loads. Random loads are discussed for the 1st time in load identifications, so that the application field of load identifications is enlarged. The second part of this paper presents in details the six-force-factor identification of helicopters. Three main aspects about six-force-factor identifications are described respectively. They are the calibration on the ground （the measurement of transfer matrix）, the measurement of the structrual response in flight and the calculation of six-force-factor （solving Eq. ）. Strains are for the first time chosen as the measurement parameters in the load identification. Not only the dynamic load but also the static load and the fatigue test data can be obtained at one time. Practice has proved that the direct measurement method of the strain stransfer matrix is simple and reliable if the number and locations of the measurement points are chosen rationally. As to measurement of moment transfer functions using eccentric forces, this paper gives expressions of transfomation matrices. The influence of the data processing and the method of solving equations on the results is also discussed in this paper. The six-force-factor of helicopters has been identified successfully. The data obtained can be used in design of the helicopters,