螺旋钻头掘削土壤的阻力矩研究

考虑进给和回转运动共同对切削厚度和切削角的影响, 引用进给回转速比m, 结合McKyes-Ali土壤三维失效模型和极限力学平衡方程, 建立了新的螺旋切削阻力矩解析公式。理论和实验研究表明, 螺旋切削阻力矩与进给回转速比m成非线性关系;m的存在使实际切削角、实际切削厚度及实际失效角都发生改变, 导致钻头切削阻力矩理论值与不考虑m影响时不同; 两理论值偏差随m没有确定的变化规律, 偏差的大小与土壤力学参数、钻具结构参数和上层土预压力等有关; 实验值与考虑进给回转速比影响的理论值有更高的吻合度, 证明了理论的正确性。

Research on Resistance Torque of a Working Auger Head

In view of the impacts of feeding and rotary motion on real cutting thickness and cutting angle, the parameter m, that is the feeding-rotational speed ratio, was introduced in the study. In combination with McKyes-Ali's three-dimensional soil failure pattern and the corresponding limited equilibrium mechanics equations, a new analytical formula for cutting resistance torque of a working auger head was deduced. Theoretical and experimental researches show that, the relationship between feeding-rotational speed ratio and cutting resistance torque is nonlinear. The introduction of the parameter m leads to changes in the real cutting angle, real cutting thickness and real failure angle, resulting in definitely different cutting resistance torque. The difference between two theoretical values doesn't follow any regular pattern as m value changes, but it is connected with mechanical parameters of soil, structural parameters of drill and pre-loaded pressure of topsoil. The experimental data being in a good agreement with theoretical value, has further testified the feasibility of such theory.