摘要
建立一个具有四自由度的力学模型,利用多自由度系统振动的理论,分析典型风荷载对小麦的影响,推导出小麦的倒伏弯矩计算公式.考虑土壤特性和小麦根须分布情况,在郎肯土压力理论基础上推导出小麦的抗倒伏弯矩.比较两种弯矩,可对小麦的抗倒伏能力进行综合评价和预测.通过所提出的模型进行多种小麦的数值试验,发现各质点的质量大小对各振型形状的影响很显著,尤其是可以改变第二振型的弯曲方向,以及解释不同品种的小麦的抗风差异现象.
A mechanical model with four degrees of freedom was established.Using the multi-freedom vibration systems theory,the effect of the wind load on wheat was analyzed and the wheat lodging moment formula was derived.Based on Rankine earth pressure theory,considering soil properties and root distributions,the lodging-resistance moment of wheat was obtained.Comparing two bending moments,the ability of wheat lodging-resistance can be predicted.The wheat numerical results show： the impact of particle mass on the each vibration mode shape is significant,especially the particle mass can change the bending direction of the second vibration mode;the difference of lodging-resistance for difference wheat is also explained.
出处
《华侨大学学报（自然科学版）》
CAS
北大核心
2012年第6期667-670,共4页
Journal of Huaqiao University(Natural Science)
基金
辽宁省自然科学基金资助项目(20092057)
关键词
抗倒伏
小麦
力学模型
多自由度系统
固有频率
模态分析
lodging-resistance moment
wheat
mechanical mode
multi-degree systems
natural frequency
modal analysis
