基于平面铲板结构改进的土壤切削阻力试验研究
Experimental study of soil cutting resistance based on structural improvement of flat blade

通过分析平面铲板对土壤切削的理论模型,研究平面铲板在90°切削倾角下对土壤的切削过程;为减小该切削倾角下的切削阻力,对平面铲板进行结构改进,在其刃缘加装6种不同长度的水平铲刀;以平面铲板和结构改进的L型铲板为切削工具,以级配土为试验对象,采用自行研制的拉拽式土壤切削试验装置进行土壤切削试验研究;通过对比分析发现,对铲板进行结构改进后,由于水平铲刀对土壤的剪切作用,使切削过程中的切削阻力显著减小;水平铲刀长度在不同切削深度下存在一个最优值,但切削深度较小时该值并不明显;最后,根据试验结果,对不同切削深度下水平铲刀的长度进行优选;采用优选值代替最优值,拟合出了水平铲刀长度随切削深度的变化曲线,并对加装水平铲刀导致切削阻力减小的内在机理进行分析。
According to analysis of theoretical model for soil cutting, cutting process of blade under cutting angle with 90 degree was investigated. In order to reduce cutting resistance of this condition during soil cutting process, the structure improvement was implemented, and six additional horizontal blades with different length was installed to blade-edge. Seven groups of grading soil cutting tests with self-designed pulling traction testing apparatus was experimentally studied. Based on the comparison, we found that horizontal blade was able to reduce cutting resistance effectively due to the shear action on soil. There was an optimum length value of horizontal blade under different cutting depth, but it is not evident when the cutting depth is small. On the basis of results, preferred length values of horizontal blade under different cutting depth were determined. The curves of length of horizontal blade with cutting depth was fitted by replacing preferred values with optimal values, and the mechanism of decrease of the cutting resistance was analyzed