基于离散元法的沥青混凝土振动切削过程的数值模拟

Numerical Simulation of Vibration Cutting for Asphalt Concrete Paving Based on Discrete Element Method

铣刨机作为沥青混凝土路面的重要养护机械,其需求量不断增长,国内自主研发高性能铣刨机已刻不容缓。数值模拟可以直观量化表达铣刨作业中铣刨刀具的受力情况,已经成为研究铣刨机整体性能的重要手段。基于三维离散元法建立符合宏观力学性能的路面模型,建立铣刨作业模型仿真量化铣刨作业过程的铣刨阻力,采用单轴压缩和劈裂抗拉试验测定沥青混凝土路面的抗压模量和抗拉模量,获得校核微观接触连接参数的宏观标准。利用三维离散元软件PFC3D编写算法生成具有不规则形状粗集料的离散元试件。通过建立运动学模型推导振动铣刨的临界条件表达式,研究附加不同振动方式对作业过程受力的改进情况,从而计算出铣刨机振动铣刨振幅和振频的优化组合数值,获得铣刨机较优的激振方式。

The demand for road miller is increasing continually as an important machine for maintenance of asphalt concrete paving. The research of domestic self-developed road miller with high-performance brooks no delay. The force of miller can be quantitative expressed by numerical simulation during working and numerical simulation has become an important mean of research for road miller＇s performance. three-dimensional discrete element method is used to model asphalt concrete paving that fits the macroscopic mechanical properties of road. Cutting process of road miller is simulated and cutting force is quantitatively expressed during simulation. Uniaxial compression and splitting tensile test are used to measure the compression modulus and tensile modulus of asphalt concrete paving, the obtained macroscopic criteria are used for verifying microcosmic parameters of contact and connection. Algorithm is programmed in PFC3 D to generate coarse aggregate with irregular polyhedron shape. Kinematic model is established to infer the critical condition of utilizing vibration cutting in road miller. The improvement of cutting force is analyzed when utilizing different mode of vibration during working process. The optimized mode of vibration is obtained, the amplitude and frequency of vibration are optimized.