| The excavator-impactor is a new construction machinery equipment as the rapid development of hydraulic excavator.lt not only has good flexibility, excavator can make full use of impactor's funnction.This makes it in mining, road construction, railway construction etc playing a large role.But in the currently, most of the excavator-impactors were modified by excavators, while excavator's working devices mainly design for scooping at first,after installing the impactor, the working environment is turnning to high frequency vibration, and thus it must to analysis the working device's dynamic characteristic, understanding the dynamic characteristics,and getting the natural frequency and dynamic response, so as to verify the structure can successfully overcome the resonance,fatigue, and other harmful effects caused by forced vibration or not.Taking the LK3000 excavator-impactor for example, analysis the working device's dynamic characteristics at high frequency impact work condition, including modal analysis and harmonic responses analysis, the main contents of this paper are listed as follow:(1)Firstly,the paper gives a brief overview to the impact mechanical and its working principle,and expounds the excavator and impact studies in present situation home and abroad, then proposes the theme of this paper, namely, stuaying the dynamic characteristic of main arm and bucket arm in the high frequency impact and fatigue life.(2)This chapter describes dynamics'relevant theoretical knowledge, and analyses the working devices'dynamic,then works out the dynamic response to the periodic impact load and the rectangular pulse,lastly, puts forward the measures to improve structure stiffness.(3)Using ANSYS software to analysis working devices'modal and harmonic responses, gets their inherent frequency and main mode in natural frequency,unserstands the harmonic peak curve at the inherent frequency,then figures out their fatigue life for the dangerous zone(4) Carrying out experimental research to bucket arm's dynamic characteristics,the result verifies the correctness of the finite element analysis results.Through analysing excavator-impact's working device dynamic characteristic at high frequency,offers the basic theory to match excavator and impactor, and the optimization design, it is important to better their performance, and longer their fatigue life. |
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