论文部分内容阅读
黏弹性减振缓冲结构可抽象为黏弹性振子(VEO)来研究其动力学行为.提出了构建考虑几何系数的分数阶黏弹性振子(FVEO)模型的一般方法.以Kelvin-Voigt分数阶黏弹性振子(KFVEO)系统为例,采用拉普拉斯变换得到其频率特征函数,并利用Mellin-Fourier积分将KFVEO系统响应从复频域转化到时域,采用多值函数的复变积分原理和留数定理获得KFVEO系统时间历程的解析形式.以安装在某300k W履带拖拉机的黏弹性悬架为工程应用实例,应用所提模型在时频域分析了其翻越障碍时应对冲击振动的减振缓冲性能,以及分数阶数和几何参数的影响.结果表明,该悬架具有良好的减振性能,在频率比0.8238处出现振动峰值;几何参数与分数阶数均对减振效果有明显影响.为复杂黏弹性缓冲减振结构的精确建模和参数化设计提供相应的理论依据.
The viscoelastic damping structure can be abstracted as a viscoelastic vibrator (VEO) to study its dynamic behavior. A general method for constructing a fractional viscoelastic vibrator (FVEO) model considering geometrical coefficients is proposed. The Kelvin-Voigt fractional viscoelasticity (KFVEO) system as an example, the frequency eigenfunctions are obtained by using Laplace transform, and the response of KFVEO system is converted from complex frequency domain to time domain by using Mellin-Fourier integral. The complex variable integration principle of multi-valued function and Number theorem to get the analytic form of time history of KFVEO system.Taking the viscoelastic suspension installed on a 300kW crawler tractor as an example of engineering application and using the proposed model to analyze the vibration damping buffer Performance and the influence of fractional order and geometric parameters.The results show that the suspension has good vibration damping performance, the peak value of vibration appears at the frequency ratio of 0.8238, and the geometric parameters and fractional order have a significant effect on the damping effect. The corresponding theoretical basis is provided for accurate modeling and parametric design of complex viscoelastic damped vibration-damping structures.