收割期芦竹底部茎秆机械物理特性参数的试验研究

Experimental research on the mechanical physical parameters of bottom stalk of the Arundo donax L.in harvesting period

试验研究芦竹底部茎秆的机械物理特性,以获得其最大破坏应力、弹性模量等机械物理特性参数,并分析芦竹切割过程中应力、应变分布状态,能为芦竹切割刀具和切割方式的设计提供理论依据和基础技术参数,对低能耗、高效率的芦竹切割器的设计具有重要的指导意义。该文利用微机控制电子万能材料试验机对收割期的芦竹底部的茎秆进行了顺纹拉伸、压缩、弯曲试验,获得试验条件下顺纹拉伸、压缩、弯曲的应力-应变曲线,并进行了分析。试验测得芦竹底部茎秆顺纹拉伸最大抗拉强度平均值为123 MPa,弹性模量值为1260 MPa;顺纹压缩最大抗压强度平均值为52 MPa,弹性模量值为595 MPa;顺纹弯曲最大抗弯强度平均值为125 MPa,弹性模量值为1715 MPa。结果表明,芦竹破坏应力参数接近毛竹,远大于玉米、小麦等茎秆的破坏应力参数,芦竹的机械化收割不宜采用传统的切割器。

Obtaining parameters of mechanical physical characteristics of the Arundo donax L. stalk such as the maximum breaking stress, modulus of elasticity, etc. through the experimental study, and offering theoretical foundation and basic technical parameters for the study of cutting and cutter for the Arundo donax L. , play a significant role in designing high-efficiency cutting device with low energy consumption and realizing the Arundo donax L. harvesting mechanization. Just like bamboo, timber, etc, the Arundo donax L. is anisotropic, non-homogenized, non-linear biomaterial, but no quantitative study has been reported on the mechanical physical characteristics of the Arundo donax L. stalk. Using the computer-controlled electronic universal testing machine to do stretching test, compressing test and bending test, along veins on the bottom stalk of Arundo donax L. , the stress-strain curves under certain experimental conditions were acquired and analyzed. The tests show that the average maximum of pulling resistance intensity along veins is 123 MPa, the modulus of elasticity is 1260 MPa; the average maximum of stress resistance intensity along veins is 52 MPa, modulus of elasticity is 595 MPa; the average maximum of bend resistance intensity along veins is 125 MPa, and modulus of elasticity is 1715 MPa. And the results indicated that the breaking stress parameters of the Arundo donax L. is similar to the Phylb- stachys pubescens, but is far greater than the breaking stress parameters Of stem stalks such as the maize, wheat, etc. So the traditional cutters are unsuitable to be adopted in the mechanization harvest of the Arundo donax L..