大豆茎秆压缩力学特性的研究

Research of Mechanics Characteristics for Soybean Stalks Compression

为了研究大豆茎秆力学性能与大豆倒伏现象的相关性及对大豆的优种筛选进行评价,通过对大豆茎秆的轴向压缩试验,测定了3个品种、不同含水率和不同距地高度的最大承载力、最大应力、弹性模量和惯性矩。结果表明:干大豆茎秆的最大承载力、最大应力和弹性模量明显高于湿大豆茎秆;沿茎秆高度方向,最大承载力和惯性矩基本呈线性下降趋势,最大值在距地高度5cm以下;而最大应力基本上不变,弹性模量变化小,最大值在距地8～30cm处,最小值均在大豆茎秆顶端。不同品种间茎秆平均最大承载力、最大应力的差异明显:品种3的茎秆两者最小,品种2的茎秆两者最大。不同品种间的平均弹性模量和惯性矩也有差异:品种3的两者最小,品种1的两者最大。

In order to study the relevance of mechanical properties of soybean and the lodging of soybean,and to evaluate mechanical performance index on crop breeding.In this paper,the axial compression experiment were performed on three different varieties of soybean stalks,different moisture content and different distance from the ground,measuring their maximum load,maximum stress,elastic modulus and moment of inertia.The results show that the maximum load,maximum stress and elastic modulus of dry soybean stalks are significantly larger than wet ones.Along the stalk＇s height direction,maximum load and moment of inertia show a downward trend,and the maximums are below the height of 5cm away from the ground.However,maximum stress and elastic modulus remain essentially unchanged.Elastic modulus change little,and the maximum is at the height of 8cm to 30cm.Their minimums are all at the top of soybean poles.The differences on average maximum load and maximum stress are obvious in variety,the third species is the smallest and the second species is the largest.There are also differences on the average elastic modulus and moment of inertia in variety,the third species is the smallest,the first species is the largest.