粘弹性缓冲系统阶变阻尼耗散机理与行为特性研究

Viscoelastic buffer is an effective approach to address the vibration problems of the heavy-duty construction machinery for working condition. However, the damping features of the viscoelastic buffer always badly match with the parameters of the vibration system due to the temperature-frequency effect of viscoelasticity, thus leading to the worse vibration control effect. To solve the above problems, this project intends to investigate the variable-order damping dissipation and behavior characteristics of the viscoelastic buffer under varying temperature and frequency conditions. The fractional constitutive model of viscoelastic material will be established by revealing the coupling mechanism between the variable-order fractional operator and the characteristic parameters responding to the temperature-frequency effect, based on which the viscoelastic constitutive behavior will be discussed. Next, the fractional damping model of the viscoelastic oscillator considering the geometric factor will be developed through exploring the mapping mechanism of physical and mechanical parameters of the buffer system and involving the transfer function between the constitutive behavior of the material and the dynamic response of the system. To study the variable-order damping dissipation characteristics of the buffer system, the element reducing and stepwise decoupling strategies, based on the spectral technology and the operational matrix, will be adopted to solve the fractional damping model. Meanwhile, the parameter matching strategy will be investigated based on APO. For engineering application, the proposed theory will be applied to updating the viscoelastic suspension of a 410 ps crawler bulldozer. After determining the optimal stiffness/damping matching relation between the viscoelastic suspension and the travelling system, the validation experiment will be carried out on the prototype. The outcomes of this project are expected to provide reference for developing high-performance viscoelastic buffers for the heave-duty construction machinery.

粘弹性缓冲结构可有效应对大型工程机械作业时产生的剧烈振动，但其动态阻尼特性的温频效应常使之与系统参数动态匹配度差，导致缓冲效果差。为解决上述问题，本项目将基于变分数阶算子对粘弹性缓冲结构变温-频阻尼耗散机理与行为特性开展研究。揭示温频特性参数与变分数阶算子的映射机理，构建粘弹性材料变分数阶本构模型，研究其变温-频阶变本构力学行为特性；梳理缓冲系统物理—机械参数的“嵌套”耦联特征，确定材料本构力学行为与系统动态响应之间的传递函数，构建包含形状因子的粘弹性振子变分数阶减振模型，利用谱配置技术和运算矩阵方法对减振模型进行单元降维和分步解耦，研究粘弹性缓冲系统阶变阻尼耗散特性，并基于APO探索参数匹配策略；将理论方法应用于某410马力履带推土机高性能粘弹性悬架的参数升级，确定悬架与行走系统的动态刚度/阻尼匹配关系，试制样机，开展验证试验。为大型工程机械高品质粘弹性缓冲结构的开发提供参考。

粘弹性缓冲结构可有效应对大型工程机械作业时产生的剧烈振动，但其动态阻尼特性的温-频效应常使之与系统参数动态匹配度差，导致缓冲效果差。为解决上述问题，本项目开展了粘弹性缓冲结构温频阻尼耗散机理与行为特性研究。.本项目采用理论与实验相结合的方法，从材料基础力学行为到系统动态响应，最后落地到工程应用，对变温-频条件下粘弹性振子的阻尼行为建模开展研究，获得了一套完整、系统且更加精准的粘弹性缓冲结构温频动态性能及振动耗散的分析方法。①探明了粘弹性本构力学行为特性的温频阶变阻尼机理，建立了粘弹性变分数阶本构模型；②深入分析了粘弹性温频迟滞特性机理，建立了粘弹性变分数阶温频动态力学模型，可实现对变温宽频条件下粘弹性动力学特性进行准确预测，并开发了专用计算软件；③建立了粘弹性振子系统典型分布阶动力学模型，结合Chebyshev运算矩阵和分数阶理论，获得了系统时频响应，掌握了参数特性；④提出了R2-ICRMOAPO多目标优化算法，其最优非支配解集所覆盖的目标空间区域更大，Pareto 解集更加逼近真实解集，可实现对粘弹性系统阻尼耗散特性的多目标优化；⑤将理论研究成果应用某工程机械新型粘弹性隔振器的开发，并进行了实车验证实验，对该系列工程机械驾驶室的舒适性提升效果显著，并作为下一代车型开发的主要技术方案。.本项目在研究过程中，逐步形成了系列阶段性成果，为我国大型工程机械高品质粘弹性缓冲结构的开发提供理论参考，对拓展变分数阶微积分理论在粘弹性工程领域的应用亦有积极的推动作用。