揉碎玉米秸秆机械特性的试验研究-农业机械化工程专业毕史业论文.pdf.docx

摘 摘 要 玉米秸秆属于粘弹性生物物料，其机械特性必然会对玉米秸秆的压缩特性和压缩 后秸秆产品特性、压缩生产工艺及压缩设备的设计、优化等有重要影响。因此，了解 被压缩玉米秸秆的机械特性及其压缩理论对压缩工艺的选择和压缩设备的设计、优化 等尤为重要。 本论文通过试验和理论分析，对揉碎玉米秸秆的可压缩性和蠕变特性进行了试验 研究。对影响揉碎玉米秸秆可压缩性和蠕变特性的主要因素进行了全面的研究与分 析，并找到了参数间的定量关系。获得如下结论： (1) 获得了压缩密度对揉碎玉米秸秆可压缩性的影响规律，压缩过程中所需 压缩力随压缩密度变化而变化。通过统计分析，得出不同试验条件下揉碎玉米秸秆体 积模量K与压缩密度p的函数关系。且分析了不同初始密度、压缩速度和含水率对揉 碎玉米秸秆可压缩性的影响规律。 (2) 结合揉碎玉米秸秆的可压缩性分析得出：揉碎玉米秸秆在不同初始密度、 压缩速度和含水率下压缩时，最佳压缩密度范围为190～380kg／m3。 (3) 根据波尔兹曼(Boltzmann)叠加原理、积分理论、迭代和多元回归分析 等理论和方法，获得了在复杂应力状态下对被压缩揉碎玉米秸秆进行蠕变特性试验测 试和理论分析的方法。 (4) 得出了不同初始密度和载荷对揉碎玉米秸秆蠕变曲线、．参数的影响规律， 建立了各阶段揉碎玉米秸秆蠕变模型。 (5) 对压捆机的核心部件压缩机构进行了设计，并基于虚拟样机技术，在CAE 环境下对压缩机构进行了仿真分析，得出了活塞在设定条件下的位移、速度和加速度 变化规律。 关键词：玉米秸秆；揉碎；可压缩性；蠕变；机械特性；压缩机构 Study Study on Mechanical Properties of Maize Straw Rubbed Abstract Maize Straw is a kind of viscoelastic material．The Mechanical properties of Maize Straw have great effect to the Compressing processing and properties of products compressed，the processing technology and the design and optimization of compressing equipments of Maize Straw．Therefore，The Mechanical properties of Maize Straw Rubbed should be studied，which will help US select the compression process，develop and optimize the compression equipments，etc． The compressibility of Maize Straw Rubbed and its creep characteristics were studied through experiments in this paper．The factors，which mainly influence the compressibility and creep of Maize Straw Rubbed，were tested in the experiments．Then the relationships between parameters were discovered after analyzing the results of experiments．Moreover, design and dynamic simulation analysis on the compressing mechanism was studied． (1)The rules of compression density influence on the compressibility of Maize Straw Rubbed were found out．The results showed that the pressure got variable谢th compression density changing．By means of regressive analysis，the mathematical model， in term of the relationship between bulk modulus and compressing density,Was obtained under different test conditions．Mea