基于EMD的某火炮身管模态参数识别

Modal Parameters Identification of Gun Barrel Based on EMD Method

现阶段火炮模态参数识别都是以快速傅里叶变换(FFT)为基础,信号必须平稳且是严格的周期信号;通常情况火炮工作状态下的信号是非平稳信号;经验模式分解(EMD)方法是一种新的非平稳的信号处理技术,EMD方法在处理非平稳信号时相对其他方法有相当大的优势;首先对某火炮身管在有限元分析软件中建模,分别在有约束和自由状态下对身管进行模态识别;然后用EMD方法对相关数据进行处理,得到身管的模态参数(频率、阻尼比、刚度矩阵、阻尼矩阵、质量矩阵),并与有限元分析方法得到的结果进行对比、分析;数值仿真证明了EMD方法在火炮领域的可行性和有效性。

The modal parameters identification of artillery is mostly based on the Fast Fourier Transform（ FFT）. However,the FFT signals must be smooth and strictly periodic. The signal was usually nonstationary in the gun working condition. The EMD method had a great advantage than other methods in dealing with non-stationary signals. In this paper,firstly,we built the model of a gun barrel in the finite element analysis software. Secondly,we identified the gun modal parameters in the constraints and free stated. Thirdly,we dealt the data with the EMD method,and got the gun modal parameters（ frequency,damping ratio,stiffness matrix,damping matrix,mass matrix）. Finally,we compared the result of the EMD method with the result of the finite element analysis method. The numerical simulation results demonstrate the feasibility and effectiveness of the EMD method for modal parameter identification of artillery.