水稻根茬-土壤复合体剪切特性试验

发布时间：2018-02-23 06:43

本文关键词： 水稻保护性耕作根土复合体剪切特性　出处：《农业机械学报》2017年05期 　论文类型：期刊论文

【摘要】：为了降低稻茬地少耕免耕过程中的阻力,提高作业质量,同时为破茬开沟装置提供设计依据,采用自制的剪切试验装置在万能材料试验机上对水稻根茬-土壤复合体进行了剪切试验,对根茬-土壤复合体含水率、土壤容重、根茬-土壤复合体的当量直径、剪切位置、剪切速度、切刃刃角、切刀刃口形状7个因素进行了单因素试验。在单因素试验的基础上选取根茬-土壤复合体含水率、剪切速度、切刃刃角3个因素进行了正交试验。单因素试验结果显示:极限剪切应力与复合体的含水率呈二次多项式函数关系,与土壤容重呈幂函数关系,与根茬-土壤复合体直径呈二次多项式函数关系,与剪切速度呈对数函数关系,剪切位置距离根茬中心越远极限剪应力越小,切刃刃角越小极限剪切应力也越小;在4种形状的刃口切刀中,凹圆弧切刃的极限剪切应力最小。正交试验结果表明:切割速度450 mm/min、含水率25%、切刃刃角15°时,极限剪切应力最小。
[Abstract]:In order to reduce the resistance in no-tillage process and improve the quality of the operation, the design basis of the ditching device for stubble breaking can be provided in order to reduce the resistance in the process of no-tillage in rice stubble field. The shear experiments were carried out on the rice stubble soil complex by using a self-made shear test device. The moisture content, soil bulk density, equivalent diameter and shear position of the root stubble soil complex were measured. On the basis of single factor experiment, seven factors, such as shear speed, cutting edge angle and cutting edge shape, were tested. On the basis of single factor test, water content and shear rate of stubble soil complex were selected. Three factors of cutting edge angle were tested by orthogonal test. The results of single factor test showed that the relationship between ultimate shear stress and water content of complex was quadratic polynomial function and power function with soil bulk density. The relation with the diameter of stubble and soil complex is quadratic polynomial function and logarithmic relationship with shear velocity. The farther the shear position is from the center of stubble, the smaller the ultimate shear stress is, and the smaller the cutting edge angle is, the smaller the ultimate shear stress is. The results of orthogonal test show that the ultimate shear stress is the minimum when the cutting speed is 450 mm / min, the water content is 25 mm / min, and the cutting edge angle is 15 掳.
【作者单位】：华南农业大学工程学院;华南农业大学南方农业机械与装备关键技术教育部重点实验室;
【基金】：公益性行业(农业)科研专项(201203059) 广东省科技计划支撑项目(2015A020208016) 国家重点研发计划项目(2016YFD0200606)
【分类号】：S152

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