Dynamic Modeling And Analysis Of Impact Mechanical Systems Of Hydraulic Power Impacting Piling Machine

The hydraulic power impacting piling machine uses impact to produce thepulse of great fertility,it is more compact than the structure of hydraulic static pilepiling machine,and it’s widely used.In this paper,a new type of impact mechanicalsystems of hydraulic power impacting piling machine is researched.By integratedusing of wave mechanics theory,Newton mechanics,Matlab data processingtechniques,and finite element simulation methods,the impact of the mechanicalsystem dynamics model of the hydraulic power impacting piling machine isestablished,then the dynamic characteristics and the impact of the piles force of thekey components of the tension of the impact mechanical systems of hydraulicpower impacting piling machine such as hammer,tension and compression box,rod,pile caps are studied.This paper provides a theoretical basis for the structuraldesign and performance assessment of the impact of the mechanical systems of anew hydraulic power impacting piling machine.In this paper, the main research work are as follows:A new type of impact mechanical systems of hydraulic power impacting pilingmachine is simplified as a "rigid body-spring-rigid body-elastic rod-rigid body-spring-elastic rod" dual impact of system model and the impact of mechanical wavedynamics model is established by using wave kinetic theory.Finally,the impact piledriving force and the dynamic response of the key components,such as hammer,tension and compression box, rod, pile caps, precast piles are gained in the impactprocess.The rod is simplified as a single spring-mass system and the vibrationmechanical model of the hydraulic power of mechanical system of the impact ofhydraulic power impacting piling machine is established by using mechanicalvibration theory,and the effect of buffer spring stiffness on impact pile drivingforce between vibration mechanical model and wave dynamics model isstudied.The result shows:The accurate impact pile driving force can be obtained byusing vibration mechanical model replacing wave dynamics model when the impactload cycle is far greater than the cycle of the elastic rod,and it need using wavedynamics model when the impact load cycle close to the cycle of the elastic rod.Based on the wave mechanical oretical model,the influence of the designparameters of the hammer,buffer springs,tension and compression box,rod,pile cap,cushion and so on for maximum impact pile driving force are studied,theresults show that the buffer spring and spring pad stiffness have bigger impact onthe impact pile pressing and are less restricted by the impact of system structure,sothe desired impact pile driving force can be obtained by choosing suitable bufferspring and spring pad stiffness.The changes of impact pile driving force and the stress-strain of thehammer,pull of the tension and compression box,rod,pile caps,and other keycomponents are gained by using LS-DYNA finite element simulation,and theresults are compareded with the calculation results of the wave mechanical oreticalmodel.