Study On Method Of Fatigue Bench Test For Boom Of Hydraulic Excavator

Excavator is one of the most widely used engineering machinery in the world,so the market is very huge.Because of the poor working environment and the complex load of the working device,the main reason for the failure of the structure is fatigue crack and fatigue fracture caused by fatigue damage accumulation.The load on the boom is usually the worst when the excavator is working.So the research on fatigue reliability of excavator boom is of great significance to the improvement of boom structure,to the enhancement of the excavator's work performance,work efficiency and reliability.In view of the above problems,a fatigue reliability bench test scheme for excavator boom is designed in this paper.Sunward SWE350 excavator is chosen as the research object,the load condition of excavator working device is calculated when the excavator boom is in the typical condition of the maximum load.Based on the calculation of pin rod load between bucket and arm,pin rod load between boom and arm,and bucket linkage load,the initial data is provided for the design of pin-type load cell and establishment of experiment scheme in this paper.On the basis of the results of the stress analysis,two kinds of test methods for the fatigue load spectrum of the boom are proposed.In order to provide the actual loading data for the fatigue test of the boom,the load of working device is tested by the specially designed pin-type load cell and the linkage sensor,the actual load condition of the boom joint is calculated.According to the existing equipment,the loading scheme for fatigue bench test of the boom is put forward,and the design and calculation of the test equipment are completed.The test load is limited inside the test device in the test scheme,which greatly reduces the influence of the equipment vibration on the external environment.Finally,the three-dimensional model of the fatigue test of the arm is established,and the finite element static analysis and modal analysis are carried out.According to the analysis results,the structural design of each component is optimized to ensure the static and dynamic performance of the designed test device to meet the test requirements.