Strength And Dynamic Analysis On Working Mechanism Of Underground Load-haul-dump Vehicle Based On Influence Of Welding

Underground load-haul-dump vehicle(LHD)is one of the necessary equipment in underground mine trackless mining operation,rely on the movement of the working mechanism to complete the loading,transport and unloading of materials.At present,the welded joints are used in the production of the working mechanism.The structural form and the quality of welding seam directly affect the strength of the working structure.In this paper,the working mechanism of 2m3 LHD is taken as an example.Study on the strength and dynamics of forward six bar linkage mechanism based on different types and quality of welded joints,the strength distribution and dynamic characteristics of the forward six bar linkage are obtained.The main work of this paper is as follows:(1)Based on the study of the force condition of the six link linkage working mechanism under the condition of inserting and shoveling,the theoretical calculation method for the strength of two typical working conditions is obtained.It is concluded that the weld geometry has a great influence on the strength of the welded structure based on the theoretical analysis of the strength of the welding structure.It lays the foundation for selecting more reasonable welding structure in the finite element analysis of strength.(2)The virtual prototype of the working mechanism of 2m3 LHD was successfully established,through parametric modeling and virtual assembly technology of SolidWorks software,and it was introduced into the dynamic simulation software ADAMS.The multi rigid body dynamics simulation of the six linkage mechanism is proposed under the two typical load distribution conditions of positive load and partial load.The motion characteristics of the three main hinge joints on the movable arm are obtained,and the maximum stress shoveling condition is obtained,it provides a basis for more reasonable strength analysis.(3)The finite element model of working mechanism under the condition of shovel is established in ANSYS Workbench,and static load analysis was carried out by adding positive and partial load.The stress concentration and the maximum stress of each component of the working mechanism are found and the distribution of dangerous section and high stress area are analyzed.The simulation results show: In the case of two different loads,the total stress of the movable arm and rocker is not changed,and the maximum stress is less than the allowable stress of the material under two different conditions.Due to the characteristics of the six linkage mechanism,the tensile stress of the connecting rod under positive load is significantly more than that under the partial load.The stress concentration occurs on bucket edge and the welding seam between the upper side plate and the crossbeam.It provides the basis for the strength simulation of welded structures.(4)The finite element simulation and research on the arm model of the welding seam between the side plate and the cross beam with different welding forms are carried out,and the influence of various factors on the weld strength is obtained.A more reasonable weld structure of anti fatigue is proposed: side plate bevel angle is 40°,fillet weld reinforcement of high dimensions not exceeding 8mm,the weld surface formed is concave.