沥青路面冷铣刨切削机理研究

发布时间：2018-10-08 18:16

【摘要】：目前路面冷铣刨切削以其较高的作业效率和作业质量,已成为沥青路面维护时清除原有路面的最主要方式。沥青路面冷铣刨切削机理的研究对于沥青路面冷铣刨理论和技术的发展、改进铣刨机设计、提高铣刨机作业效率等,无疑具有根本性的意义。沥青路面冷铣刨切削作业时刀具的运动方式与稳定土拌合机、滚筒采煤机和隧道掘进机同属于旋转切削,但是作业介质和作业机理完全不同。故本文首先对比探讨多种沥青混凝土本构模型,最后选定JC本构模型来表征材料特性;其次,通过对铣刨转子的结构和工作原理进行理论研究,推导出刀尖运动轨迹与刀具受力表达式,并利用MATLAB描述了不同速度下刀尖的运动轨迹与刀尖速度变化规律以及不同刀具参数对于切削力的变化规律;然后在ABAQUS软件环境下对不同切削速度以及不同切削深度下的应力与应变、切削温度以及能量损耗等方面能进行多次模拟仿真,得到刀具刀尖处应力集中,所受应力最大,等效应变随速度影响较小,在1.5左右波动,这和采用的剪切失效准则相关;切削速度对于切削温度有较为明显的影响;得到切削温度与切削深度变化规律,切削深度越深加剧了刀具的磨损,并且切屑带走的热量引起损伤能量增加;切削深度对于切削力有较为明显的影响。故对切削速度与切削深度的合理深入研究是有一定必要性的。本文采用虚拟数值技术进行实际作业过程的模拟,能够在理想状态下顾全材料特性,并可以了解整个切削路面的瞬时过程,得到的变化云图与数据对实际工况具有一定参考意义。同时可以对作业机理的分析作出预测或验证,对切削机理深入研究提出了新思路,而且仿真分析也对刀具的设计、材料选择以及切削过程中的切削速度和切削深度选用上具有很大指导意义。
[Abstract]:At present, cold milling and cutting of pavement has become the most important way to clear the original pavement during the maintenance of asphalt pavement because of its high working efficiency and working quality. The research on the cutting mechanism of cold milling planing of asphalt pavement is undoubtedly of fundamental significance to the development of theory and technology of cold milling planing on asphalt pavement, improving the design of milling machine and improving the working efficiency of milling machine. The moving mode of the cutting tool in cold milling and cutting of asphalt pavement belongs to rotary cutting, but the working medium and working mechanism are completely different from those of the stable soil mixer, the drum shearer and the tunnel tunneling machine. In this paper, several kinds of constitutive models of asphalt concrete are compared and discussed. Finally, JC constitutive model is chosen to characterize the material characteristics. Secondly, the structure and working principle of milling planer rotor are studied theoretically. The expression of tool tip motion track and cutting tool force is deduced, and the change law of tool tip motion track and cutting tip velocity under different speed is described by MATLAB. The change law of cutting force under different cutting tool parameters is also described. Then the stress and strain at different cutting speed and depth, cutting temperature and energy loss can be simulated several times under the environment of ABAQUS software, and the stress concentration at the cutter tip is obtained, and the maximum stress is obtained. The equivalent strain fluctuates slightly with the velocity, which is related to the shear failure criterion adopted, the cutting speed has obvious influence on the cutting temperature, and the variation law of cutting temperature and depth is obtained. The deeper the cutting depth is, the more the tool wear is aggravated, and the damage energy is increased due to the heat taken away by the chip, and the cutting depth has an obvious effect on the cutting force. Therefore, it is necessary to study the cutting speed and depth. In this paper, the virtual numerical technique is used to simulate the actual operation process, which can take into account the characteristics of the material in ideal state, and can also understand the instantaneous process of the whole cutting road surface. The obtained cloud map and data have certain reference significance to the actual working conditions. At the same time, it can predict or verify the analysis of the working mechanism, put forward a new idea for the further study of the cutting mechanism, and simulate the design of the cutting tool. The selection of material and cutting speed and depth in cutting process is of great significance.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.217

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