Solid Granules Medium’s Transmission Performance Simulation Under Vibration Excitation Conditions

In recent years, precision forming technology has been paid more and more attention,it is a product of modern fusion of new and traditional technologies, involving multipledisciplines computers, new materials, measurement techniques, forging, casting and otherfields, and are moving efficiently multiple directions rapidly, including lightweight,precision and so on. Of which solid granules medium forming technology is a metalmolding new technology which traditional medium replaced by solid particles, due to thespecial nature of the solid granules, the process has good mobility, strong pressure, can benon-uniform pressure transmission, and other characteristics, has significant advantages interms of forming. It is a plastic processing technology frontier, can be widely used inautomotive, chemical, aerospace and other fields.Solid granules have many special properties distinguished from solid particles andliquid special nature, these peculiarities are due to non-uniform stress distribution causedby its discrete nature. Thus, the internal power transmission assembly of the particleproperties of the study and research on basic research is the discrete nature of the mediumsolid particles, the most important problem, the nature of the force transmission of themovement of the particulate media is necessary to study, to solid particles forming newmedia technology to lay the theoretical foundation mechanics.The subject comes from the National Natural Science Foundation of China " granularmedia ultrasonic vibration plate forming process and theoretical studies (project number:51305385)." This article is based on discrete element modeling software PFC2D forcetransmission properties of solids medium numerical simulation analysis, the main work isas follows:According to the basic principles of discrete element method to explore the basicideas of discrete element simulationAccording to the size of the barrel and consider the computational cost and otherfactors to establish a viable and efficient numerical simulation model in the simulationsoftware PFC2D. Reveals when compressing and after compressing the press ram’s stress will increasewhen it get closer to the cylinder wall, the cylinder wall’s stress will increase when it getcloser to the press ram. And the corresponding variation of granulesBy applying vibrational excitation at the bottom of the granular medium system，theeffect of vibration frequency, amplitude and increasing filling level of granular medium onforce law of the granular media was studied. A series of laws were discovered, such as，thefrequency of vibration source is greater，the amplitude is smaller and the stress waveamplitude of dynamometer position is smaller etc. When packing height increases to thediameter of cylinder and the compression becomes larger, less time is needed to achievestabilization of the granular medium system with increasing frequency value and stressfluctuation is smaller after the stabilization. Besides, the force on cylinder wall showsattenuation trend with increasing force transmission distance from the beginning ofvibration source.