| The main working environment of the camellia subsoiler is mountainous and hilly areas,the working environment is complex,and the stress conditions are changeable.Among them,the chassis frame,as the key component connecting the crawler chassis and the chassis drive train,needs to ensure its working reliability.This paper studies and analyzes the typical working conditions of the chassis frame of the Camellia oleifera subsoiler,and analyzes the mechanical characteristics and vibration characteristics of the chassis frame under the dynamic load state in detail.Under the premise of ensuring the strength and stiffness of the chassis frame,the lightweight design of the chassis frame is carried out.The specific research contents are as follows:(1)Theoretical analysis is made on the two typical working conditions that affect the chassis frame of Camellia oleifera subsoiler—driving condition and subsoiling condition.According to the typical working conditions,the detailed force analysis and derivation are made respectively,and the load of each component is deduced to the chassis frame.The corresponding force balance equation system is established,and according to the equation system,the specific force of the chassis frame under each working condition is obtained.(2)Using the Ls_Dyna module in ANSYS to carry out dynamic simulation analysis on the soil revolving process of a single subsoiling tool,the average soil resistance of a single subsoiling tool in the vertical ground direction during the soil revolving process is 1286.4N.According to the analysis results,determine the specific force of the chassis frame at the moment when the subsoiling head is submerged.(3)The parametric solid model of the subsoiler chassis frame was established in Inventor,and the model was imported into ANSYS Workbench to establish the finite element model.The modal analysis of the chassis frame is carried out to obtain the first six natural frequencies and vibration modes of the frame,and a brief analysis of the first six vibration modes is carried out.By comparing the first six natural frequencies of the chassis frame with the external excitation frequency,it is known that the first six-order natural frequency of the chassis frame is at least 65.4Hz,and the external excitation frequency is 3-47Hz.The natural frequency of the chassis frame can avoid the external excitation frequency,indicating that the chassis frame can effectively avoid the resonance phenomenon.(4)According to the specific force of the chassis frame under each working condition,these loads and constraints are applied to the finite element model of the frame.Based on this,the strength and stiffness of the frame under typical working conditions were analyzed,and the stress and deformation cloud diagrams were obtained.The chassis frame has the largest stress under the deep loose driving condition,and the maximum stress point appears at the engine support beam at the bottom of the frame.The maximum stress value is 146.2MPa,and the existing structure can meet the work requirements and has the potential for optimization.The stress test is carried out on the chassis frame.According to the comparison between the experimental results and the simulation results,the maximum error between the experiment and simulation is within 20%,which can verify the accuracy of the finite element model established this time,which shows that the finite element analysis has certain reliability,and this finite element model can be used as the parametric model for further optimization.(5)According to the characteristics of beam element modeling,the sensitivity expressions of the wall thickness variation of chassis frame members to natural frequency,maximum stress and mass are obtained.Compared with the original structure,the new light-weighted frame reduces the maximum stress of the chassis frame by 10.7MPa and reduces the weight of the chassis frame by 16.2%under the premise of ensuring the strength and rigidity of the chassis frame,achieving the lightweight design goal of the chassis frame. |
