Strength Analysis And Fatigue Life Prediction Of Hydraulic Excavator Boom

Boom is the vital parts of the hydraulic excavator working attachments. It is subjected to frequent alternate loads caused by bucketdigging or arm digging, and expiration is often happened due to the alternate impacts suffered in actual conditions. As a consequence, boom is easy to fail. Taking the boom of Sunward SWE470excavator as research object, the static strength and fatigue strength were analyzed. The optimum position of the boom hinge points and structural optimization were studied.The statics models of working attachments were established for structural finite element analysis. The mathematical models of theoretical digging force and key hinge points of the force were set up as well.Boom finite element model was established to conduct the analysis of displacement boundary conditions and simulation. Through the results comparison of the boom typical working conditions and the compound condition ones, the most dangerous section was found.Based on ADAMS, the simple parametric modeling was set up, and relative optimization of the hinge point was conducted; with APDL parameterized finite element model of the boom shell-solid unit was built in order to implement sensitivity analysis and structural optimization.Taking SWE470as experiment platform, boom stress and strain test was carried out in order to verify the correctness of the finite element model and offer real load spectrum for the subsequent fatigue analysis.Experimental data was converted to different levels of cyclic stress by filtering and rain flow counting. Through the stress analysis in ANSYS, combined with S-N fatigue curves of the material and the given load spectrum, finite life design method was used in order to conduct boom life estimation in MSC.Fatigue, which gives further guidance for optimizing the design of the boom.