Vibration Analysis Of Circular Saw Blade For Cutting Shrubs At High Speed And Optimization Design

As an important cutting tool in agriculture and forestry,circular saw blades for shrub have high working efficiencies and excellent machining qualities in a complex outdoor working environment,especially in the case of high rotating speeds,performing more superb.With the increases of the rotating speeds,numerous problems of strong vibrations and noises are further revealed when the circular saw blades work.Therefore,this thesis is mainly based on the operation standard of trimming and restoring small shrubs for lightweight design of circular saw blades to achieve the effect of vibration and noise reduction.In this thesis,the finite element ANSYS software is adopted to simulate the circular saw blades,and solve the vibration,noise,gas-solid coupling and stress problems.The main work includes the following aspects:(1)Based on the common circular saw blades,a series of circular saw blades with silencing holes and radial silencing slots were designed.The natural frequency variation of circular saw blades with different hole types are analyzed through modal analysis.Further,combining the theory of traveling wave vibration to study the influence of silencing holes and radial silencing slots on the vibration of circular saw blades.(2)The circular saw blades are intercalated,and the circular saw blades with damping intercalations of different thicknesses are designed.The effects of damping intercalations of different thicknesses on the natural frequencies of circular saw blades are analyzed,which obtains the effects of damping intercalations of different thicknesses on the vibration laws of circular saw blades.Finally,a design scheme of the best vibration reduction effect is determined.(3)Aiming at the design scheme of circular saw blades with opening holes and interlayers,the characteristics of surface flow field and noise variation of circular saw blades of different schemes are studied by using the methods of Fluent flow field analysis and noise analysis,furthermore,the influence of gas-solid coupling effect on the stress of circular saw blades of various design schemes is searched.Finally,determine a design scheme with the best noise reduction effect.(4)In order to verify whether the designed circular saw blade optimization scheme meets the actual working requirements,the stress analysis and fatigue analysis of the circular saw blades of various schemes are further implemented to calculate the stress,deformation and fatigue life of the circular saw blades of different design schemes.This thesis optimizes the structural parameters of circular saw blade for small portable cutting machine,and finally provides theoretical reference for vibration and noise reduction design of circular saw blade.