林木联合采育机进料辊填充蜂窝结构的力学特性  

Mechanics Characteristics of Feeding Roller Filled with Honeycomb Structure of Forest Combine Harvester

作　　者：王栋 王典[1] 刘晋浩[2] 黄青青[2] Wang Dong;Wang Dian;Liu Jinghao;Huang Qingqing(Beijing Forestry University,Beijing 100083,P.R.China)

机构地区：[1]北京林业大学工学院,北京100083 [2]北京林业大学,北京100083

出　　处：《东北林业大学学报》2020年第6期93-99,104,共8页Journal of Northeast Forestry University

基　　金：中央高校基本科研业务费专项资金项目(2016ZCQ08);国家科技支撑计划项目(2015BAD07B02)。

摘　　要：针对林木联合采育机作业过程中,进料辊定位原木、带动原木在机头内加速启动或减速停止时,由于进料辊与原木接触面积较小而造成的钉齿对原木损伤严重的问题,提出一种双V附翼型负泊松比(NPR)蜂窝结构以改变进料辊的刚度,增大进料辊与原木有效接触面积,从而减小对原木的损伤。通过分析双V附翼型NPR蜂窝结构特点,基于位移法建立其X和Y方向面内弹性常数的理论模型,并构建不同结构参数的实体模型,制备该结构胞元试验构件。通过有限元仿真研究了蜂窝胞元厚度(t)、胞元上夹角(θ2)、胞元下夹角(θ1)与胞元半宽(l)4组参数对该结构面内弹性常数的影响。结果表明:其Y方向等效弹性模量(Ey)随t的增大而增大,随θ1、l的增大而减小,θ2对其影响较小;X方向等效弹性模量(Ex)随t、θ1和θ2的增大而增大,随l的增大而减小,而泊松比值νxy和νyx只受θ1和θ2的影响,但同一参数对νxy和νyx的影响趋势相反。模拟LAKO 43HD采育机作业机头工作时所受的垂直压力,在t为4、5 mm、θ1为30°、35°、θ2为70°、75°、l为29、31 mm时,采用双V附翼型负泊松比蜂窝结构的进料辊的压缩量达到了原进料辊的10%~30%,可以有效减小进料辊对原木的损伤。理论模型可以近似表征该结构的面内力学性能,对进料辊采用双V附翼型NPR蜂窝结构时选取各项参数值具有一定的指导意义。Aiming at the problem of serious damage to logs caused by the small contact area between the feeding roll and logs when feeding roll locates logs and drives logs to accelerate start or slow down in the machine head during the operation process of forest combine harvester,a double V-winged negative Poisson’s ratio(NPR)honeycomb structure was proposed to change the stiffness of the feeding roll and increase the effective contact area between the feeding roll and the logs,thereby reducing the damage to the log.By the displacement method,the theoretical model of the elastic constants in the Y-direction and X-direction plane was established by analyzing the characteristics of double V-winged NPR honeycomb structure,and the solid models with different structural parameters were constructed,and the cell experimental components of the structure were prepared.The effects of thickness t,lower angle θ1,upper angle θ2 and cell half-width l on the in-plane elastic constants are studied by finite element simulation and test.The results show that Ey,the Y-direction equivalent modulus of elasticity about the honeycomb,increased with the cell thickness of honeycomb walls,and decreased with the lower angle and half width of honeycomb,and the upper angle had less influence on it.Ex,the X-direction equivalent modulus of elasticity about the honeycomb,increased with the lower angle,upper angle and cell thickness of honeycomb walls,and decreased with the half width of honeycomb,while,the Poisson’s ratioνxy andνyx are only affected by lower angle and upper angle,but the same parameter had opposite effect onνxy andνyx.Simulating the vertical pressure on the working head of LAKO 43 HD harvester,when t are 4 and 5 mm,lower angles are 30°and 35°,upper angles are 70° and 75°,and the half width(l)are 29 and 31 mm,the compression of the feeding roll with double V-winged NPR honeycomb structure reaches 10%-30% of the original feeding roll,respectively,which can effectively reduce the damage of the feed roll to the log.It has a ce

关 键 词：采育机 进料辊 森林工程 树木损伤 面内弹性常数 

分 类 号：S776.31[农业科学—森林工程] S776.33[农业科学—林学]