摘要
草捆的形态稳定性是衡量其质量的主要指标之一。目前常用的方捆机所生产的产品在不同程度上仍存在着草捆形状和尺寸不规范、外型和尺寸不稳定以及散捆率较高等问题。草物料属于粘弹性物料,在外力作用下所产生的变形由永久性变形和可恢复变形组成,而可恢复变形所产生的变形恢复力与草捆的密度和应力松弛有关。当草捆的密度不均匀时将引起草捆的不同部位所产生的变形恢复力出现差异,这是引起草捆形态不稳定的根源。该文在实际压捆生产条件下对不同物料进行试验,应用流变学的理论,研究压缩过程中由于喂入不均匀引起的草片上、下截面变形恢复力的变化规律和差异,以及应力松弛对变形恢复应力的影响,建立相应的数学模型,并为压捆机的设计和实际生产提供依据。
The bale stability affects its quality. Nowadays, some problems exist in cubic bale that formatted in baler the geometrical instability, the bale scattered before using or bale size varied in a wide range, Hay under compressing has shown that the formation of wafers is a material deformation phenomenon, governed by such properties of the material as viscoelasticity. Based on viscoelastic consideration from the observation, the total deformation has both recoverable and irrecoverable components, the recoverable deformation associated with recoverable force have relationships with bale density and stress relaxation. Unstable recovery of bale originates in diverse recoverable force. Mathematical model was established to investigate the influence of recoverable force and stress relaxation by applying rheological theory in cubic bale production. Principles of recoverable force as well as stress relaxation in the compression were discussed in the paper, the difference between the upper section and the lower one due to uneven feeding shows great influence on bale stability. It is essential for both baler design and practical production.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2006年第2期103-106,共4页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金资助项目(50165001)
