Research On The Strength Of Wheel-mounted Maneuvering Arm Considering Residual Stress

The wheel loader is the most used equipment in construction machinery.The boom is an important component in the working device of the loader.The boom plate and the beam are combined by welding.The front end is connected to the bucket,and the rear end is connected to the front.The frame supports the bucket for loading.When the loader is working,it will generate large static load and impact load on the ring welding area of the beam of the boom plate,and it is easy to produce local cracks and deformation.Therefore,it is necessary to put forward higher quality requirements on the strength and rigidity of the boom to meet the working conditions.After the welding of the boom plate and the beam,the stress cannot be released,which ultimately causes defects such as shrinkage deformation and torsional deformation of the boom plate,and a large residual stress will be generated at the weld seam.Satisfy the assembly accuracy,during the correction process,the circular welding of the boom plate and the beam will produce a new correction stress;the working stress will also be generated at the welding seam during use.The strength and stiffness of the arm are reduced,and the fatigue strength of the welding area of the boom and the beam will cause certain damage.Loaders must withstand large static loads and impact loads when they work,and the boom will yield in some places,which will cause structural failure and affect the safety of the whole machine and the normal use of parts.Therefore,when designing the boom,it’s extremely important to think out the effect of residual stress on the strength of the boom when performing structural strength analysis on the ring structure composed of the boom plate and the beam welding.Many companies and scientific research institutions at home and abroad are paying more and more attention to the study of residual stress.Therefore,it is of great practical significance to study the calculation and analysis of welding residual stress,straightening stress and working stress of the boom.This article mainly studies the influence of the loading mobile arm welding production site,the correction production site and the use process on the strength of the boom;through Sysweld welding simulation simulation,Workbench correction simulation simulation and static simulation simulation of the boom ground shoveling,to get the respective The size and distribution law of stress;measure the stress of the welded arm and the corrected arm through the production site,and compare with the data of the finite element simulation to verify the reliability of the simulation;then focus on the impact of the boom Factors in the correction process: loading force position,correction distance,correction times and holding time.Finally,the control variable method is used to analyze the influence law of each influence factor on residual stress;the stress on the welding seam of the boom when the loader is working is studied.Select the ground shoveling working state,calculate the force of each hinge point of the boom,use solidworks software for modeling and Ansys stress analysis,and accurately simulate the overall stress state of the boom;then the residual welding stress at the weld of the boom,The corrected stress and the maximum working stress are superimposed,and the longitudinal stress is easily exceeded After the yield limit,the lateral stress is close to the yield limit,and the stress in the thickness direction is small;finally,measures to control the residual stress in the production site of the boom correction are formulated and the purpose of improving the strength of the boom is achieved by rationally modifying the model.Through research and example verification,this paper establishes a feasible simulation analysis method for loading residual stress,corrected stress and working stress of the mobile manipulator,provides theory and guidance for the analysis of residual stress in the boom welding process,and promotes the finite element analysis The method is used for the analysis of welding,correction and work of the loading manipulator and its application in actual engineering.Using the correction and fixation method designed in this paper and the optimized production process of the boom structure can significantly reduce the problem of local cracks and deformation at the welding seam of the loading mobile arm during work,and can meet the requirements of product strength.