Simulation And Study Of Excavation Resistance Of Backhoe Hydraulic Excavator

Hydraulic excavators play an important role in various engineering construction projects,as the most widely used engineering equipment in construction machinery.The working device acts as the executing device of the hydraulic excavator and directly acts on the excavation object.Therefore,the working device of the excavator has also become the focus of many scholars.Based on excavator working equipment,research on excavating performance and structural strength has been a hot topic in excavator research.However,both the analysis of excavation performance and the study of structural strength must firstly determine the load spectrum of the working device during the operation.Therefore,it can be considered that obtaining the accurate load spectrum of the working device is the basis for the in-depth study of the hydraulic excavator.Aiming at the difficulty of obtaining the load spectrum of the working device during the excavation process,this paper proposes a method for obtaining the load spectrum of the working device by numerical simulation based on the experimental test of a domestic 36 t backhoe hydraulic excavator.The specific research contents are as follows:(1)Based on the analysis of the structural features of the backhoe hydraulic excavator working device,the kinematics model of the excavator working device was established,which laid the foundation for the subsequent establishment of excavation resistance model for excavating soil.(2)The three excavation trajectories corresponding to the three typical excavation methods of hydraulic excavator were selected.The time history curves of the working device rotation angle and hydraulic cylinder pressure under the corresponding excavation method were recorded.(3)In the LS-PREPOST platform,a bucket dynamic simulation model for excavating soil was set up.The bucket model traced the excavation trajectory during the test as much as possible,and was brought into LS-DYNA for solving.The simulation results and measured data were performed.By contrast,the reliability of the simulation model was verified.(4)Based on the bucket excavation soil dynamics simulation model,the influence of the bucket digging angle and cutting speed on the bucket obstruction during the excavation process was further studied.Through further calculations,the optimal bucket cutting angle and cutting speed under various excavation methods are obtained.