北方垄作萝卜物理力学特性

Physical and mechanical properties of ridging radishes in Northern China

通过北方垄作栽培收获期青萝卜和红萝卜的田间和实验室测定,探寻其几何参数、松土位置参数优化组合及拔取力等物理力学特性。采用数理统计方法对收获期萝卜的几何特性进行分析,得出了两种萝卜主要几何特性指标值的变化区间和分布频率;通过拉伸试验对收获期萝卜根茎结合部抗拉强度、拔取力等力学特性进行测试,应用软件Design-Expert Version 6.0.10分析,得出了青萝卜和红萝卜根茎结合部抗拉强度分别为(2.45±1.23)105Pa和(2.17±1.08)105Pa,最小抗拉力分别为90N和110N,土壤自然状态下所需拔取力分别为(191±113.8)N和(197±107.2)N,部分萝卜会发生枝断漏收现象;采取松土拔取收获方式,当一侧松土位置参数优化组合为松土深度15～26cm、松土距离10～20cm时,青萝卜所需拔取力小于90N,当一侧松土位置参数优化组合为松土深度18～24cm、松土距离12～16cm时,红萝卜所需拔取力小于110N,不会发生拔断漏收现象。为拔取式萝卜收获机的设计提供理论依据。

Based on the field and lab measurement on the ridging green and red radishes in harvest time in north China,the physical and mechanical properties of radishes,such as geometric characteristics,the optimum parameters combination of the loosening location,and pulling force,were explored.The mathematic statistics method was employed to analyze the main geometric properties.The variation range and distribution frequencies of main geometric properties indexes of the green and red radishes were found out.The tensile test was carried out to measure its mechanical properties,such as cohesive strength between stem and root of radishes,pull force in harvest,and the data were analyzed by means of software of the Design-Expert Version 6.0.10.The experimental results indicated that the cohesive strength between the stem and the root of the green radish and the red radish were in the range of（2.45±1.23）105Pa and（2.17±1.08）10 5 Pa,and the minimum anti-pull force was 90 N and 110 N,the maximum pull force for the green and red radishes in condition of natural growth in harvest were in the range of（191±113.8）N and（197±107.2）N,respectively.Optimum parameters combination of the loosening location were that the depth was from 15 to 26 cm,and the distance was from 10 to 20 cm,using pull method to harvest the green radish,and that the depth was from 18 to 24 cm,and the distance was from 12 to 16 cm,using pull method to harvest the red radish.The study provides theoretical data for designing radishes harvester.