| As early as more than 3,000 years ago and even in the new era,humans have had a history of excavating coal and metal minerals through open-pit mining.Until today,open-pit mining still occupies an indispensable position in the mining of coal due to its large output,low cost,high recovery rate and complete use of resources.This article focuses on the fatigue problem of the components of the WK-75 mechanical mining excavator for the reel and spool shaft components.On the one hand,MSC ADAMS software was used to simulate the whole machine.On the other hand,multi-axial fatigue life of reel and spool shaft components was studied based on finite element analysis and multiaxial fatigue theory.The main content includes the following four aspects:1.Multiaxial fatigue theoryAccording to the analysis of the actual stress characteristics and fatigue failure modes of the WK-75 mining excavator drum and spool shaft assembly,it is known that the complex and varied forces of the components belong to the category of multiaxial fatigue damage.Read a lot of theoretical content on multi-axial fatigue failure criteria,damage mechanisms,etc.,and provide theoretical support for the analysis of fatigue life of reel and spool shaft components.2.Load spectrum extractionBecause the actual load measurement is complicated,this paper uses virtual prototype technology to simulate a working cycle of the excavator.Establish the geometric model of the main parts of the excavator working device in the UG NX environment;import the middle file of the paradise format into the dynamic simulation software ADAMS,set the spatial position constraint,and apply the velocity to the motion pair of the pushing mechanism and the rotary mechanism Drive,add the load according to the actual force;establish the cable plug-in module,carry out the modeling of the lifting wire rope and the gear,and apply the winch drive to the drum.Set a simulation time of 30 s,extract the load history of the reel and drum shaft assembly and lift the hinge point of the wire rope to provide input load for multi-axis life analysis.3.Finite element simulation of reel and reel shaft assemblyAccording to the actual project size,the finite element model of the reel and reel shaft assembly is established,and the dangerous working conditions during the working of the assembly are established.Structural statics analysis was performed in ANSYS Workbench to obtain the maximum stress and strain distributions and values and to obtain dangerous sections.Derive the finite element simulation results under the stress of each unit to prepare for fatigue life analysis.4.Analysis of Fatigue Life of Reel and Reel Shaft ComponentsBased on the above analysis results,the static analysis results and the load spectrum related data files obtained from the ADAMS dynamics simulation analysis were imported into the fatigue analysis software Fe-Safe to correlate and establish the fatigue load spectrum.The von Mises-Goodman algorithm,which is the most commonly used multi-axial fatigue life analysis,is used to simulate the multi-axial high-cycle fatigue life of reel and spool shaft components.Under the national high-tech research and development plan(836 project)project "75 cubic meters large open-pit mining excavator"(Project Number: 2012AA062001)funding.This paper presents a complete interpretation of the entire cycle history of the WK-75 excavator excavation.For the first time,the fatigue life of the WK series excavator is analyzed.It can provide theoretical explanations and explanations for the fatigue damage problems that occur during the actual use of the excavator,and provide references for the regular maintenance and replacement of the drum and spool shaft assembly in the future and structural improvements. |
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