Simulation Analysis Of Excavator Based On Multi-body Dynamics And Particle Dynamics Coupling

Hydraulic excavator working equipment,which suffered all kinds of complex loads,is the executive device to complete a variety of work tasks.Due to the adverse working conditions and the complicated loading situation,the digging resistance and the dynamic loads of the hinge were obtained difficultly.So the structure strength analysis was much more difficult.In this paper,a 21.5 tons hydraulic excavator was selected as the research object.The digging resistance was obtained more accurately by the particle dynamics analysis,so as to further the external loads of each hinge were obtained,which provides the work load for the structure strength analysis.The article finished the work as below:At first,the three-dimensional model of the excavator working equipment was established,and the kinematic analysis of the excavator working device was realized by the measured displacement curve of the boom,the stick and the bucket cylinder.The real excavation process was simulated to obtain the excavation trajectory curve,the center of mass of the bucket movement speed,and the rotation angular velocity of the hinge joints of bucket-stick and bucket-link mechanism.The particle model of the excavation materials was established by the discrete element method,the particle factory and other solving parameters were set up,and the motion rule of the bucket was established by using the bucket kinetic parameters.The actual condition of the bucket excavation was simulated,and the digging resistance of the different material particles was obtained,and then the dynamic loads at the hinge joints were gotten by the multi-body dynamics analysis.Finally,through the transient analysis of the boom and the stick,the internal stress and strain distribution of the structure under the dynamic load were obtained,the dangerous point and the dangerous section of the structure were determined.It will provide the reference datas to study structural optimization and fatigue strength analysis.In this paper,the multi-body dynamics was coupled with the particle dynamics,and the dynamic loads of the working device was analyzed in detail,which solved the problem that the digging resistance was difficult to be determined and provided the loading datas for the transient analysis of the structure.