提出一种改进的飞行器动弯矩识别方法,该方法引入了频域积分算法,避免了时域方法中消除趋势项以及滤波所带来的问题。对加速度响应进行两次积分得到结构弹性位移响应,然后根据模态叠加理论求解出广义坐标,最后结合模态弯矩识别截面的动弯矩响应。通过悬臂梁试验验证了算法的有效性,并与传统方法识别出的结果进行对比。结果表明,新方法的识别结果更接近试验实测动弯矩响应,具有更高的精度。最后将该方法应用于某型号飞行器,并给出了识别结果。
An improved identification method based on the mode superposition method for dynamic bending moment responses of flight vehicles is proposed in this paper.A frequency domain integration algorithm is introduced to avoid the problems caused by the tendency eliminating and signal filtering when using the time-domain integration method.Firstly,the displacement response of the flight vehicle is obtained by integrating the acceleration responses twice.Then,the generalized displacement is calculated by the mode superposition method.Finally,the dynamic bending moment response is identified by utilizing the modal moment.The validity of this approach is verified through an experiment on a cantilever beam,where the results identified by using both the time-domain integration and frequency-domain integration method are presented.It is demonstrated that the results obtained by the improved method are closer to the real moments than that obtained by the classical time-domain method,namely the improved method has a higher accuracy.Furthermore,the proposed method is applied to estimate the dynamic bending moment responses of a vehicle during the flight,and the results are given.