Study On Mechanical Properties Of Clustered Bamboo And Optimization Of Cutting Tools

Bamboo is a non-wood forest resource.With the promotion of"substituting bamboo for wood",the demand for bamboo is increasing.Due to the long bamboo stalks and many branches of bamboo,it causes problems such as low efficiency and difficulty in pruning.At present,bamboo pruning process has become the most time-consuming and laborious link in the front-end bamboo cutting process,seriously restricting the efficient development of bamboo industry in China,so there is an urgent need for mechanized pruning.In essence,bamboo picking can be regarded as the process of action between the knife and the bamboo branch’s roots.In this paper,the bamboo branch’s root is the research object,and its physical and mechanical properties are measured and tested.Based on the cutting characteristics of the branch,we explored its cutting mechanism,analyzed and designed the tickling device.The finite element analysis software was used to dynamically simulate the tickling process to explore the changes in the force and power consumption of the bamboo branch’s roots under different parameters of the tool,which provides theoretical support for the optimal design of the bamboo tickling mechanism.The main tasks of this research are as follows:(1)Taking the bamboo branch’s roots of three kinds of clumping bamboos,such as Neosinocalamus affinis,Bambusa rigida Keng et Keng f and Dendrocalamus Latiflorus Munro in Yibin City,Sichuan Province,as the research object,the morphological characteristics,physical properties and shearing mechanical properties were measured.The average height under the branches of Neosinocalamus affinis,Bambusa rigida Keng et Keng f and Dendrocalamus Latiflorus Munro is 3.54m,5.69m and 3.16m,respectively;the average moisture content is 62.29%,57.81%,46%;the average density is 1411.54kg/m~3,1161.83kg/m~3,1135.45kg/m~3;the average value of shear strength is 16.55MPa,27.03MPa,and 30.2MPa,respectively.The variation rule of density and shear mechanical properties of different parts of stump of three kinds of bamboo branch’s root was positively correlated with the height of bamboo pole.(2)We carried out theoretical research on the bamboo picking process,and determined the combination of the picking mechanism and the slicing machine to form the plan of the picking and slicing integrated machine.We analyzed the influence of the support method and cutting method on the cutting performance,and analyzed the force of the tool during the cutting process.It is determined that under the working condition of bamboo picking as tangent,the main influence on the performance of the tool is the blade angle and the thickness of the tool.With reference to the tick structure of the combined feller,the shape and size parameters of a cutter were preliminarily determined,and a prototype of tick and slicer was trial-produced and tested.It is found that the product cannot effectively cut the branches,and the cutting edge angle and thickness of the cutter need to be improved and optimized.(3)We established a dynamic simulation model for the bamboo tickling process through ANSYS/LS-DYNA finite element analysis software.According to different tool blade angles(5°,10°,20°,30°,40°)and different tool thicknesses(1mm,2mm,3mm,4mm,5mm)and other different tool parameters,an orthogonal experiment was established for simulation experiments.We compared and analyzed the stress distribution and change of the props,the size and change of the cutting force,and the size and change of the energy.The results show that the best solution is the cutting edge angle of 20°and the thickness of 5mm.In this state,the maximum equivalent stress of the tool is 558.43MPa,the maximum force required to cut bamboo branches is 254N,and the energy consumption at this time is 0.151J.