Study On Compaction Performance Experiment And Analysis Of Industrial Prototype Of Double-Frequency Compound Roller

In the process of the compaction with double-frequency compound roller, at any time,there are two exciting forces with different frequencies act on the compacted materialssimultaneously. It can make more materials particles with different natural frequencies inresonance, reduce the friction and cohesion between each other and create favorableconditions for compaction. With the popularization and application of the technology, theefficiency and quality of compaction must be improved effectively. Based on thetheoretical analysis and experimental research, an industrial prototype ofdouble-frequency compound roller (hereafter refer to as the Industrial Prototype) isdeveloped. The compaction performance of the prototype is studied by use of experimentand Finite Element Method deeply. The works lay the foundation for the industrializationof the double-frequency compound roller.A nonlinear dynamic model for roller-soil interaction is set up with the plasticdeformation of soil considered. Compared with the classical linear model, the nonlinearmodel is more close to the actual work condition of roller. Based on the nonlinear model,the kinetic and dynamic characteristics of the testing prototype of the double-frequencycompound roller are simulated and analyzed during compaction. The influences of soilparameters on the movement of the roller and interaction forces between roller and soil areachieved. Meanwhile, it is pointed out that the natural frequency of the roller-soil system isnot constant, but depend on the amplitude of exciting force. Some typical nonlinearproperties, such as the superharmonic resonance and the subharmonic resonance are shownin the amplitude-frequency of the system.The reasonable vibration parameters of the Industrial Prototype are confirmed basedon theoretical analysis and experiment, and the Industrial Prototype is developed by meansof reforming the20-ton single wheel roller of Liugong.The contrast tests between the Industrial Prototype with the same tonnageconventional single-frequency roller CLG620of Liugong (hereafter refer to as the Single-frequency Roller) are completed. The vibration parameters, the performance ofstarting/stopping vibration and compaction of the two rollers are determined and compared.It is shown that the parameters of the Industrial Prototype satisfy the design requirements,and the amplitude distribute uniformly along the axial direction of the vibratory roller. Thepressure impact of the two rollers is quite similar as start vibration with high amplitude. onthe contrary, the pressure peak of the Industrial Prototype is a little higher when startvibration with low amplitude. In the process of stopping vibration, either high or lowamplitude is used, the maximum pressure in hydraulic system of the Industrial Prototype isabout5%lower than that of the Single-frequency roller. It is prove that the IndustrialPrototype is more gentle during stopping vibration. Compared with the Single-frequencyRoller, the Industrial prototype has a little less compaction effect on top soil. Its averagecompaction degree is91%which is a little lower than that of the Single-frequency Roller93%. the compaction effects of the two rollers on bottom soil are equivalent, and theaverage compaction degrees both are83%. As for the middle soil, the Industrial prototypeprovides a higher compaction degree up to86.8%than the Single-frequency roller’s83%.It is shown that the Industrial Prototype has more superiority in compacting middle andbottom soil.A two-dimensional finite element analysis model for the process of compaction withthe Industrial Prototype is established. The vertical stress, plastic strain, surface subsidenceof the compacted soil and the contact stress between roller and soil are analyzed duringcompaction. The distribution and change properties of the parameters mentioned above arestudied. Some rules of the influences of vibration amplitude, travel speed and soil’sparameters are analyzed deeply. these provide the reason for intelligent use of thedouble-frequency roller, the basis for the reasonable utilization of the double-frequencyroller is provided.