林木采育机多密实度蜂窝辊的径向压缩响应  

Radial compression response of honeycomb rollers with multi dense degrees for forest harvester

作　　者：张高谦 王典[1,2] 曲云飞 刘晋浩[1,2] Zhang Gaoqian;Wang Dian;Qu Yunfei;Liu Jinhao(School of Technology,Beijing Forestry University,Beijing 100083,China;Key Laboratory of Forestry Equipment and Automation of State Forestry and Grassland Bureau,Beijing Forestry University,Beijing 100083,China;Ocean College,Zhejiang University,Hangzhou 316021,Zhejiang,China)

机构地区：[1]北京林业大学工学院,北京100083 [2]北京林业大学国家林业和草原局林业装备与自动化重点实验室,北京100083 [3]浙江大学海洋学院,浙江杭州316021

出　　处：《北京林业大学学报》2022年第7期135-145,共11页Journal of Beijing Forestry University

基　　金：中央高校基本科研业务费专项(BFUKF202114)。

摘　　要：【目的】针对为林木采育机而设计的蜂窝进料辊,研究其在采伐时夹紧和翻转工序的模拟工况下,密实度差异对压缩响应的影响。【方法】将15套蜂窝辊按照密实度划分为3种等级,经由理论模型和模拟仿真分析,对多密实度下的力学和吸能特性的变化做量化探究。选出其中3套制备试件,进行线弹性阶段内的径向压缩试验,利用数字图像相关技术对压缩过程中试件的变形进行监测,比较微观上塑性铰处的结点变形,同时对比仿真与试验的结果,进而总结双V附翼蜂窝进料辊的变形模式。【结果】仿真结果显示:平台阶段下随着密实度增长约10%,蜂窝辊的等效应力上升幅度处于2 MPa以内,但吸能量则提升了近乎6倍。试验结果表明:线弹性阶段下相同幅度的密实度提升,虽然导致质量增大约59.78%,但接触力却获得约3.4倍的提升。变形观测后提出准静态压缩下的V型变形模式,在离散系数低于6%的情况下获得了验证。【结论】蜂窝辊在密实度为0.25~0.40范围内的压缩响应表现为:以壁厚和层数为主要变量的密实度分别与等效应力和吸能量均具有显著非线性的正相关关系;在近似密实度下,增加壁厚,有助于获得更高的抗压强度,减少层数则促进了吸能特性的提升;双V附翼蜂窝进料辊在周向的变形机制显露出不均匀的拉胀现象。[Objective]The radial compression response of honeycomb rollers with multi dense degrees for forest harvester was studied under simulated working conditions,that is,clamping and overturning process during logging.[Method]15 kinds of rollers were divided into three grades according to different dense degrees.In order to obtain the quantitative exploration of mechanical and energy absorption characteristics,a combined theoretical and numerical study was designed.Then 3 of them was selected for manufacturing,and radial compression tests in linear elasticity phase were carried out.After monitoring with digital image correlation technology,the node deformation at the plastic hinge was compared.By comparing the results of simulation and test,the deformation mode of roller of double V-wing honeycomb(RDVH)with multi dense degrees was studied.[Result]The simulation results in the platform stage showed that,with the increase of dense degree by about 10%,the increase of equivalent stress of honeycomb roll was within 2 MPa,but the energy absorption increased by nearly 6 times.The test results in the linear elastic stage showed that the same increase in dense degree acted as a trigger for a mass increase of 59.78%,while it had largely led to the promotion of contact force to about 3.4 times.The V mode deformation pattern was proposed in this work,which could be verified when the dispersion coefficient was less than 6%.[Conclusion]The compression response of RDVH with dense degrees in the range of 25%−40%could be shown as follows:to begin with,the dense degree,which is significantly induced by wall thickness and number of layers,has a remarkable nonlinear positive correlation with equivalent stress and energy absorption.Furthermore,under approximate dense degrees,the increase of wall thickness could be capable to meet higher compressive strength,while the decrease of the number of layers would contribute to the improvement of energy absorption.Finally,the deformation mechanism of RDVH in circumferential directions shows unev

关 键 词：进料辊 双V附翼型蜂窝 林木采育机 负泊松比 径向压缩响应 数字图像相关技术 

分 类 号：S776.2[农业科学—森林工程]