松材线虫疫木树蔸铣削过程仿真及优化

针对松材线虫疫木所处环境复杂、难以携带普通林业设备到达疫木位置的问题,需对实地铣削松材线虫疫木树蔸粉碎机的切削刀具进行减阻特性研究,最终达到设备轻量化的目的。阐述了树蔸粉碎机的结构、工作原理及操作方法;以切削刀具单刀片为研究对象,基于Ansys的Ls-Dyna有限元显式求解程序进行松材线虫疫木树蔸铣削过程的仿真计算,构建出平均切削阻力与切削刃后角、楔角、线速度间的关系模型并进行解析;然后进行铣削过程的刀具参数优化。结果表明:影响平均切削阻力的单因素顺序依次为楔角、后角和线速度;双因素交互作用效应中后角和楔角对平均切削阻力的影响较为明显。由优化结果可得,当后角为12.94°、楔角为38.33°、线速度为9.91m/s时,平均切削阻力达到最小值22.29 N。松树疫木树蔸实木切削验证试验结果表明:平均切削阻力实测值与预测值的误差均值为10.09%,基本一致,说明该松材线虫疫木树蔸铣削过程仿真可用于树蔸粉碎机切削刀具参数优化。通过切削刀具减阻优化,树蔸粉碎机总质量最终减轻了34.4%,达到设计目标质量要求。

Milling process simulation and optimization of pine stump infected by Bursaphelenchus xylophilus

Pine wood nematode is a complex disease system dominated by Bur sap he lenc hus xylophilus,which is transmitted by longicorn beetles,long-distance transmission by human activities,host pine trees and environmental factors.At present,there is still no economic,practical and effective means of prevention and control.By cutting the diseased trees and breaking the disease-infected pine stumps into particles or fragments,the larvae and eggs of B.xylophilus can not survive through the winter,so as to effectively control the disease.In view of the complex environment of pine wood infected by B.xylophilus,it is difficult to carry the common forestry equipment to the location of pine trees.There is a need to explore the lightweight equipment and cutting tools with the drag reduction characteristics for milling the disease-infected pine stumps.This study described the structure,working principle and operation method of tree stump crusher;the single blade of cutting tool was used as the research object.Based on the Ansys Ls-Dyna finite element explicit solution program,the simulation of the disease-infected pine tree stump milling process was carried out.The relationship between the average cutting resistance and the cutting edge back angle,wedge angle and linear velocity were constructed and analyzed,then the tool parameters of the milling process were optimized.The results showed that the order of single factor influencing average cutting resistance was as follows:wedge angle,back angle and linear speed.In the interaction effect of two factors,the influence of the back angle and wedge angle on the average cutting resistance was obvious.It was discovered that the optimization results were the average cutting resistance reaching the minimum value of 22.29 N at the back angle of 12.94°,wedge angle of 38.330 and linear speed of 9.91 m/s.Since the tool rotated at a high speed,the wireless resistance strain gauge sensor was used to measure the cutting force of diseased pine stumps in the verification test.The test results showed that the average relative error between the measured values and the predicted values was 10.09%,which was almost the same as the analysis results,showing that the simulation of the disease-infected pine stump milling process could be used to optimize the cutting tool parameters of pine stump crusher,and could achieve better tool drag reduction optimization effect.Through the optimization of cutting tool drag reduction,the final total weight of tree stump crusher was reduced by 34.4% to 21 kg,meeting the design target requirements.