铣刨刀具与路面互作用的冲击与摩擦动力学特性研究

The impact behavior and internal friction system of interaction between milling cutters and road are the study objects of this research. The impact and friction dynamic characteristics of interaction between milling cutters and road is studied according to the theories of finite element method, discrete element method, impact dynamic, friction, contact mechanics, damage mechanics and thermodynamics aiming at improving the milling efficiency, reducing milling energy and cutter consumption. Firstly, the road breaking dynamic model is established and the evaluation model of impact breaking efficiency is proposed. The milling parameters are optimized to reduce road milling energy consumption. Secondly, dynamic model of road breaking by divided flexible milling cutter is established based on thermosetting coupling method to reveal the internal relation among impact load, stress and strain distribution, and cutter failure. The prediction model of impact damage and wear is proposed to reduce cutter consumption. Finally, dynamic model of multi friction pair system for cutter breaking road is established to reveal the self-rotatory mechanism of cutter breaking road. The prediction model of cutter self-rotatory performance is proposed to make uniform cutter wear and long lifetime. The research results will provide a theory basis and technical support for the design of high efficiency and low consumption milling equipment, and break through the common foundation issues of impact and friction dynamic behavior.

本项目以公路铣刨机刀具与路面互作用的冲击行为及其内部摩擦系统为研究对象，以提高路面铣刨效率、降低铣刨能耗和刀具消耗为目标，结合有限元、离散元、冲击动力学、摩擦学、接触力学、损伤力学及热力学等理论，开展铣刨刀具与路面互作用的冲击与摩擦动力学特性研究。首先，建立路面破碎动力学模型，提出冲击破碎效率评价模型，进行铣刨参数优选，降低路面铣刨机能耗；其次，基于热固耦合方法建立分体式柔性化铣刨刀具破碎路面体动力学模型，揭示冲击载荷、应力应变分布与刀具失效的内在关联，提出冲击损伤与磨损的预测模型，减少刀具损耗；最后，建立刀具破碎路面体的多摩擦副摩擦系统动力学模型，揭示刀具破碎路面过程中的自旋转机理，提出刀具自旋转性能预测模型，使刀具磨损均匀、使用寿命延长。研究成果将为设计高效低耗铣刨装备提供理论依据和技术支撑，并突破冲击与摩擦动力学行为的共性基础问题。

路面铣刨机是沥青路面养护施工机械的主要设备之一，其上的铣刨刀具直接与路面互作用，其性能直接影响路面铣刨装备工作机构的铣刨效率。刀具在铣刨路面的同时受路面的反作用，其工作条件极其恶劣且复杂多变，极易导致其断裂和磨损等失效，其中既包含刀具破碎路面的冲击损伤问题、与未崩落路面的摩擦磨损问题，也包含摩擦热力学问题和高低应力转换的疲劳过程问题。针对磨损问题，刀具在与路面互作用过程中应具备自旋转能力，刀具的自旋转能力既与刀具和路面的接触、摩擦有关，也与刀具和刀座的接触、摩擦有关，研究该能力可归结为刀具在包含两个摩擦副的摩擦系统中的动力学问题。针对以上问题本项目主要进行了铣刨刀具作用下路面冲击破碎动力学特性研究、路面反作用下铣刨刀具冲击损伤与磨损特性研究、铣刨刀具自旋转摩擦系统动力学特性研究三项研究内容。建立了二维铣刨刀具破碎路面FEM-SPH模型、三维铣刨刀具破碎路面SPH-SPH热力耦合模型、三维分体铣刨刀具破碎路面FEM模型等，研究了刀具作用下的路面体裂纹萌生、切割块度、路面体颗粒位移特征、应力分布及应力状态等，为降低路面铣刨能耗奠定理论基础；同样利用三种模型研究了路面反作用下的刀具切割载荷及其分布、应力分布及温度场分布等，为减少刀具损耗提供理论依据；建立了刀具与刀座互作用瞬态动力学模型和简化二维显示动力学模型，分析了刀具在与刀座互作用下的位移及载荷特性，揭示了刀具破碎路面过程中的自旋转机理，为刀具均匀磨损、保持切割性能提供理论支撑。项目研究成果为设计高效低耗铣刨装备提供基础理论和技术支撑，有利于提高路面铣刨装备的可靠性和高效性，降低能耗和刀具损耗。