基于小波变换的间隙结构系统动力学参数识别及建模

Based on Wavelet Transform of Research on Parameter Identification and Dynamic Modeling in Vibration System with Clearance

以坦克的身管-衬瓦总成结构为研究对象,研究考虑身管间隙的动力学建模方法对抑制由间隙导致的振动以及建模的不精确问题.首先建立了基于正则化理论的含间隙因素的身管-衬瓦结构空间缩减模型,在此基础上采用灵敏度分析方法确定影响模型的关键参数为阻尼参数;基于小波变换理论的参数辨识方法获取间隙时变阻尼参数,构建了考虑间隙和润滑非线性因素的身管-衬瓦结构动力学理论模型和仿真模型;最后采用实体相似模型对所提出的方法以频响函数偏差度为指标进行误差评价,验证该建模方法的有效性和正确性.结果表明:常规阻尼参数的身管-衬瓦结构动力学方程和试验模型的频响函数的前4阶频率误差分别为16.6%,5.6%,1.5%,3.1%;含时变参数的身管-衬瓦结构动力学方程和试验模型的频响函数的前4阶频率误差分别为4.8%,2.8%,1.6%,1.4%;引入间隙时变阻尼参数的身管-衬瓦结构仿真模型和实验模型频响函数的前4阶频率误差分别为2%,0.8%,0.2%,0.6%.证明该动力学建模方法有效提高了含间隙及润滑非线性因素的身管-衬瓦结构动力学模型精度.

Nonlinear vibration and modeling errors for the clearance,controlled by Dynamic modeling methods with clearance,is studied based on the structure model of lining and gun barrel.First,according to the actual model of barrel,the Space-Reduced-Order model of gun barrel with clearance is put forward based on the Regularization Theory.The sensitivity analysis method is used to determine the key parameters of the model as damping parameters.Next,the time varying damping parameter is obtained by parameter identification based on WT(Wavelet Transform).The theory model and finite element model of gun barrel is modeled with clearance and lubrication.Last,the scale model is designed and tested by the proposed method.The effectiveness and accuracy of this method are validated by evaluating the error of the frequency-response function.The results show that the frequency error between the test model and general theory model of gun barrel is 16.6%,5.6%,1.5%,and 3.1%,respectively;the frequency error between the test model and theory model of gun barrel with clearance is 4.8%,2.8%,1.6%,and 1.4%respectively;and the frequency error between the test model and finite element model of gun barrel with clearance is 4.8%,2.8%,1.6%,1.4%,respectively.