垃圾炉渣力学性质的颗粒流模拟

Simulation of Mechanical Behaviour for Municipal Solid Waste by Discrete Element Method

基于离散单元法理论和PFC3D软件,采用平行胶结模型来模拟炉渣中的胶结作用,建立了城市垃圾炉渣的细观颗粒模型。将模型细观参数和材料宏观力学性质联系起来,标定了模型的细观力学参数,将数值模拟结果和室内试验数据进行了对比。结果表明:离散元方法可以较好的模拟炉渣的应力-应变变形关系;细部结构调整的变化速率是影响模型受力变形机制的主要因素;改变边界刚度,分析了边界刚度对剪切强度参数和压缩模量的影响。从细观角度揭示影响炉渣强度的因素,对离散单元法的应用有一定的价值。

Based on discrete element theory, the microscopic model of particle flow for MSW has been established by PFC3D software. The parallel-bonded is employed to simulate the cementation in municipal solid waste （MSW）. The microscopic parameters and the macroscopic mechanical properties of the model are related, so as to calibrate the micro-mechanics parameters of the material. Comparison between the results of numerical simulations and laboratory tests under confining pressure shows good agreement. The result also showed that the change rate of microscopic structure is the key factor of the deformation mechanism of the model. The influence of boundary stiffness on shear strength parameters and compressive modulus was analyzed through changing the boundary stiffness. It reveals factors that influence the strength of MSW from the microscopic point of view and is valuable for developing the applicability of the DEM.