基于离散元法的沥青混凝土切削数值模拟

发布时间：2018-01-06 18:50

本文关键词：基于离散元法的沥青混凝土切削数值模拟　出处：《湘潭大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着高速公路的不断发展，，路面养护机械中的路面铣刨机的需求量也随之增加。路面铣刨机的工作原理是利用子弹头刀具对损坏的沥青混凝土路面进行切削，再重新摊铺新的沥青混凝土。沥青混凝土是一种具有粘弹性和流变特性的多相复合材料，而有限元在处理非连续介质力学有着固有的缺陷。本文提出采用离散元数值方法来模拟沥青混凝土的切削，从而预测刀具的受力，分析离散元颗粒流软件PFC中二维和三维在模拟沥青混凝土切削的优缺点，深入地研究沥青混凝土切削中刀具受力的变化，得到合理、最优的刀具工作参数，达到提高切削效率的目的。本文主要工作如下： 1、介绍路面铣刨机的工作原理和沥青混凝土数值方法研究的现状和进展，介绍离散元颗粒流软件（Particle Flow Code简称PFC）在研究沥青混凝土切削问题上的优势和其基本原理。 2、采用微机控制万能试验机对沥青混凝土进行室内单轴压缩实验，测得沥青混凝土的弹性模量和抗压强度。 3、以沥青混凝土的胶浆理论为基础结合颗粒流软件内置的本构模型建立沥青混凝土的二维和三维模型。采用颗粒流软件的FISH语言编写程序建立虚拟的单轴压缩试验和劈裂试验对沥青混凝土离散元模型进行校核，校准其抗压强度、弹性模量、泊松比和抗拉强度。 4、采用AutoCAD建立刀具的模型导入PFC2D建立沥青混凝土的二维切削模型，采用PRO/E建立刀具的模型导入PFC3D中建立三维的切削模型，分别进行切削模拟，分析刀具受力，得出三维的切削模拟更适合于模拟子弹头刀具切削沥青混凝土，预测刀具的受力。 5、先采用单因素法，后采用正交试验法分析切削速度、切入角和切削深度三因素对子弹头刀具在切削沥青混凝土的切削力的影响，得到最优的切削参数为： c=5m/s，0=45°，a p=5mm。
[Abstract]:With the continuous development of highway, the demand of pavement milling machine in pavement maintenance machinery is also increasing. The working principle of pavement milling machine is to use bullet cutter to cut the damaged asphalt concrete pavement. The asphalt concrete is a kind of multiphase composite material with viscoelastic and rheological properties. The finite element method has inherent defects in dealing with discontinuous medium mechanics. In this paper, the discrete element numerical method is proposed to simulate the cutting of asphalt concrete, so as to predict the force of cutting tools. The advantages and disadvantages of 2D and 3D in simulating asphalt concrete cutting in discrete element particle flow software PFC are analyzed. The change of cutting tool force in asphalt concrete cutting is deeply studied and the reasonable and optimal cutting tool working parameters are obtained. The main work of this paper is as follows: 1. The working principle of pavement milling machine and the research status and progress of asphalt concrete numerical method are introduced. This paper introduces the advantages and basic principle of particle Flow Code (Particle Flow Code) in the research of bituminous concrete cutting problem. 2. The indoor uniaxial compression test of asphalt concrete was carried out by using a microcomputer controlled universal testing machine, and the elastic modulus and compressive strength of asphalt concrete were measured. 3. Based on the slurry theory of asphalt concrete and the constitutive model built into the particle flow software, the two-dimensional and three-dimensional models of asphalt concrete are established. The virtual uniaxial compression is established by using the FISH language of the particle flow software. Shrinkage test and splitting test were used to check the discrete element model of asphalt concrete. Calibrate its compressive strength, elastic modulus, Poisson's ratio and tensile strength. 4. The cutting tool model of AutoCAD is introduced into PFC2D to establish the two-dimensional cutting model of asphalt concrete. The cutting tool model established by PRO/E is imported into PFC3D to establish a three-dimensional cutting model. The cutting simulation is carried out respectively and the cutting tool force is analyzed. It is concluded that the 3D cutting simulation is more suitable for simulating the cutting of asphalt concrete with bullet cutters and predicting the force of the cutting tools. 5. The single factor method is used first, then the orthogonal test method is used to analyze the influence of cutting speed, cutting angle and cutting depth on the cutting force of bullet cutter in cutting asphalt concrete. The optimum cutting parameters are obtained as follows: cn = 5 m / s 0 ~ 45 掳/ p ~ (-1) ~ (5) m ~ (-1).
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U418.32

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