| The operating conditions of crawler-type dynamic compactor are more serious than that of crawler crane.An operating cycle is made up of rammer's lifting and release.The sudden release of rammer is always accompanied with huge rebound so as to produce great impact vibration.If using the method of static study,the boom's real working state can't be reflected.So a method of establishing and solving the boom's dynamic equation is provided.In this paper,firstly,the structure of boom system,operating condition and calculation parameters of the YTQH800 hydraulic crawler dynamic compactor are provided.The physical model of the boom system under the operating condition is simplified to the dynamics model of a single degree.The kinematics differential equation is set up,and the dynamic change regularity of kinematics differential equation is obtained by using the fourth order precision method.To observe the kinematic orderliness of boom system directly,VB program is written to get the displacement curve,the speed curve and acceleration curve of boom system.The dynamic change regularity of the boom's structure performance is obtained,and the weakness existing in the boom system is found.Then,through the finite element method,the boom's finite element model is established in the ANSYS software.Using the transient dynamics method,the operating condition of the rammer sudden release is calculated.The structure stress change regularity of the boom is reflected more really,and the basis for the arm frame structure design and improvement is provided.Finally,this method is used to analyze the reason of an accident of boom bending.The improvement suggestions are provided for the design.For the subsequent boom structure of dynamic compactor,the theoretical basis for the design and improvement of boom is provided from the analytical approach and research results.The analytical approach and research results are also important significance for fatigue life assessment of the boom system. |
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