Fatigue Life Research On Hydraulic Excavator Work Device

Along with the quickly developing of national economy and the speeding pace of the overall construction of a well-off society, engineering machinery acts as an improving important role in some areas,sush as city consructing, farmland water conservancy,energy exploitation and national defense construction,not only makes contributions to the improving the labor productivity,speeding the engineering construction,but also reducing the labor intensity. Being the major equipment of mechanical constructing,hydraulic excavator is indispensable engineering machinery. For the complex and changeful engineering objects,large loade and bad environment quality,the rupture offen appears in arm or boom,which brings large economy losses to the enterprises. Fatigue break-down is the main failure mode of the hydraulic excavator, fatigue behavior affects the working behavior and efficiency.Because of the product’s longer designing cycle,higher costs,harder prediction for product’s potential problems,the traditional designing and development process has been unable to adapt to the more and more competitive market.Therefore,using the multi-functional,efficient CAE technology,combine with the test study, to guide the research of excavator’s working device is important.In this paper,the fatigue life of a certain hydraulic excavator’s working device is researched.the main works of the study are as follows:(1) The excavator’s digging resistance, theory excavating force and gyroscopic moments are analysised to be the load basis of the FE analysis. six conditions are determined as the postures of FE analysis and fatigue life study;(2)Through the finite element(FE) analysis of the excavator’s work device based on the HyperMesh and ABAQUS software,the critical areas of the work device are obtained,which is the basis of the cumulative fatigue damage calculation;(3)By the nominal stress method and the equivalent structural stress method,the fatigue life of the excavator is predicted on the basis of fe-safe, the critical nodes’cumulative fatigue damage is calculated.the result shows that the fatigue life of the working device contents with the design demand. what’s more,the equivalent structural stress method is nicer to predict the weld life;(4)The fatigue test on the work device of the excavator is studied, the result shows:the excavator’s device shows no crack phenomenon after undergoing the required circles,its fatigue performance is nice.and also this results is match the emulation results.