硬涂层复合结构非线性刚度及阻尼辨识

Identification of nonlinear stiffness and damping for hard-coating composite structure

针对硬涂层复合结构共振衰减的时域响应,研究了基于Hilbert变换辨识硬涂层复合结构的非线性刚度及阻尼的方法。首先,确定了硬涂层复合结构共振状态下自由衰减的运动方程,进而推导了辨识该复合结构非线性刚度及阻尼参数的原理性公式;其次,用数值算例证明了辨识算法的正确性;然后,提出了将辨识算法应用于硬涂层复合结构非线性刚度及阻尼参数辨识的流程;最后,进行了实验验证,辨识出单面涂敷NiCrAlY+YSZ硬涂层的悬臂钛板非线性刚度及阻尼参数,并与未涂层试件进行了比对。结果表明,涂覆硬涂层后钛板的刚度非线性增强,阻尼增大,硬涂层具有减振效果。

Based on the resonance decay response of time domain,a method to identify the nonlinear stiffness and damping was proposed using Hilbert transform.First,the free decay motion equation of the hard-coating composite structure under resonance status was determined and the formulas to identify nonlinear stiffness and damping parameters were derived.A numerical example was used to verify the correctness of the proposed identification algorithm.Then,the procedure of identifying the above parameters was presented.Finally,a titanium plate coated with NiCrAIY ＋ YSZ hard coating was chosen as a study case,the nonlinear stiffness and damping parameters of the composite plate were identified and compared with the results of uncoated plate.It is shown that the hard coating can enhance the nonlinearity and increasing the damping of the structure,thus,improving the effect of vibration reduction.