竹材碾压开纤的有限元分析

Finite Element Analysis of the Bamboo Splitting Fiber under Compression

竹材碾压开纤法是制备长竹纤维的主要方法,目前由于理论研究的滞后,竹子粗纤维的提取处于低水平阶段,实现碾压开纤的高效高质量生产是目前急待解决的问题。拟通过建立竹材碾压的有限元力学模型,找到定量研究竹材碾压开纤的方法,从而进一步获得碾压开纤的加工参数。基于竹子结构特点,从研究竹材碾压开纤原理入手,研究建立了碾压开纤的有限元力学模型,分析了碾压开纤过程中竹子纤维和基体的应力、应变变化,结果与实际情况相符合;对碾压过程的运动仿真较清晰地模拟了竹材碾压开纤的过程,结果表明:对预处理后维管束含量45%的竹材,碾压棍直径按咬入角取最小值60 mm,竹材水平初速度为30 mm·s^(-1)时,可以获得较好的开纤效果。研究初步揭示出竹材碾压开纤的机制,找到了一种有效研究竹材碾压开纤的方法,从而可以为进一步确定碾压开纤的最优加工参数,设计专用高效的竹材碾压开纤设备奠定基础。

At present,the main method to product the long bamboo fiber is to crush the bamboo to split the fiber.But now,the theoretical research lags behind,the extraction of bamboo crude fiber is at a low level.It is urgent to realize high efficiency and high quality production of splitting bamboo fiber.This paper aims to find the method to quantitatively optimize the crushing and splitting of bamboo fiber and obtain related processing parameters,by building the finite element mechanical model.Based on the characteristics of bamboo structure and the principle of splitting bamboo fiber under compression,the finite element mechanical model of crushing bamboo fiber was established.The changes in the stress and strain of bamboo fiber and substrate in the process of crushing were analyzed,and the results agreed with the actual situation.The motion process of crushing and splitting bamboo fiber was clearly simulated.The results indicate that for the pretreated bamboo containing 45%vascular bundle,when the minimum diameter of the roller is set to be 60mm according to the angle of nip,and the horizontal initial velocity of bamboo is 30 mm/s,the best fiber splitting effect can be obtained.Thus,the mechanism of splitting bamboo fiber was revealed,and the optimal processing parameters were determined.It may provide a reference for the design of special and efficient bamboo crushing and fiber splitting equipment for bamboo.