刀齿切削角对绞刀生产效能影响的数值分析

为分析刀齿切削角对绞刀生产效能的影响,基于颗粒离散元PFC2D软件,对不同刀齿切削角下刀齿体切削过程进行建模与数值分析,获得了刀齿-土体相互作用过程中的土颗粒速度场、位移场特征及切削土体的破坏形态,并全程记录了刀齿功率的动态演化过程。结果表明,刀齿切削角度越大,其所需功率越大,切削角度从30°增大至45°、60°时,其最大功率分别增加约2.2、3.3倍;刀齿切削角度越大,土体破碎越好,越易于泵吸带离,而切削角度较小时切削下的土体呈长条块状,难于卷入进入绞刀中心。

Numerical Simulation on Effect of Cutting Angle on Efficiency of Cutter Teeth

Based on the theory of discrete element method (DEM) and the particle flow code program (PFC2D), mechanism of soil cutting during working of cutter head was investigated. The model of soil cutting by a cutter tooth was established and the simulation was conducted to represent the dynamic process of soil cutting including velocity, displacement fields of the soil particles around the tooth tip. The failure modes of cut soil were investigated and the changing process of soil cutting power was recorded. The results show that the required cutting power is closely relative to cutting parameters of the tooth such as revolving velocity on its axis, translation speed and cutting angle. The soil failure modes in soil cutting include the stripe shape, the smashed cluster shape and the smashed particle shape. The size of cut soil blocks is smaller with increase of the cutting angle and the required cutting power becomes larger. The required cutting power will increase about 1.2 and 2.3 times respectively when the cutting angle is up to 45° and 60° from 30°.