Fast Forging Press Pressure Oil Pipeline Under The Action Of Fluid-structure Coupling Vibration Research

Pipeline is the commonly component of conveying fluid in industrial field,which is an indispensible part of several mechanical equipments. For highpressure, big flow, forging frequency of75times/min of the80MN fast forginghydraulic press, the reversing frequently of the fluid in the pipeline produces thefluid-structure interaction(FSI) between the fluid and the pipeline, which causethe pipeline vibration and noise. Pipeline vibration causes the serious destructionof the piping system because of resonance and fatigue damage of the pipeline.Therefore, it is necessary to study the vibration characteristic of the pipesconveying fluid with the FSI, to optimize the constraint conditions of thepipeline, to reduce the vibration and noise, to safeguard the normal operation ofthe mechanical equipment safety.Based on further studying the waterhammer theory, pipeline vibrationmechamism and so far all kinds of pipeline vibration mathematical models, inthis paper, the more complete14-equation model of the vibration of the pipesconveying fluid was established, taking the multiple coupling mechanisms, thegravity and any place into account. Using the Laplace transform, the transfermatrix method (TMM) and the software of MATLAB, the straight high pressuerpiping of the80MN fast forging hydraulic press was solved, which obtained thefrequency response characteristic curve and natural frequency of the pipelinevibration under the different constraint conditions and providing theoryfoundation for avoiding pipeline resonance.The ANSYS finite element model of the pipeline which is a high-pressureoil-taking pipeline of the80MN fast forging hydraulic press was also establishedin this paper. Applying the finite element simulation software of ANSYSWorkbench12.0, the pipeline vibration mode of was analyzed. The pipe systemwas optimized by changing the parameters and the constraint conditions of thepipeline. The result shows that the FSI makes the natural frequency of thepipeline vibration slightly increase; with the increase of the pipeline Yong’smodulus, the equivalent stress substantially doesn’t change, the total deformation slightly reduces, the natural frequency of the vibration slowlyincreases; with the increase of the pipeline Poisson’ radio, the equivalent stressand the total deformation slightly reduce, the natural frequency of the vibrationslowly increases; the proper constraint condition can reduce the equivalent stressof the pipeline causing by the impact of the fluid and the total deformation of thepipeline, improve the whole rigidity of the pipe system, in order to achieve thepurpose of reducing the vibration, noise and local energy loss of the pipeline.