碎玉米秸秆卷压过程的流变行为试验

Rheologic behavior of chopped corn stalks during rotary compression

为青贮圆捆打捆机的设计和工艺提供基础的力学数据,需要探明碎玉米秸秆卷压过程的流变规律,在分析卷压成型原理的基础上,搭建了碎玉米秸秆卷压试验台,对碎玉米秸秆进行了卷压试验和应力松弛试验。研究了卷压过程中碎玉米秸秆的流变学特征,采用线性黏弹性理论,构建了伯格斯模型,用残数法对应力松弛曲线进行拟合,获得了应力松弛模型及其参数,计算其决定系数。利用相关公式求解,进一步得到伯格斯模型中的黏弹性参数E1=18.33kPa、k1=994.81kPa、E2=27.64kPa、k2=2342.49kPa。由于黏性系数远大于弹性模量,可以初步判断碎玉米秸秆卷压过程的流变行为偏向于流体,这对于深入研究碎玉米秸秆的卷压工艺,实现工艺和装备的优化设计,具有积极作用。

In order to provide basic date for design and technology for round trapped baler,it is needed to understand the rheologic laws of chopped corn stalks in the course of rotary compression.A test bed was developed for analyzing the principle of rotary compression and forming.Rotary compression the chopped corn stalks,and the rotary compression test and stress relaxation experiments of chopped corn stalks were studied.The rheological characteristics of chopped corn stalks in rotary compression process was investigated.Using linear viscoelastic theory,the Burges Model was constructed.Fitting the stress relaxation curve through residual method,the stress relaxation model and its parameters were got,and the coefficient of determination was calculated.Burges Model’s viscous-elastic parameters was solved using relevant formula,and E 1 was 18.33 kPa,k 1 was 994.81 kPa,E 2 was 27.64 kPa,k 2 was 2 342.49 kPa.The viscosity coefficient was far greater than the elastic modulus,so the rheologic laws of chopped corn stalks tend to fluid.The study provide a reference for the further study on the technology of chopped corn stalks’ rotary compression,and the optimization design of techniques and equipment.