Computation And Characteristic Analysis Of Free Vibration For Pipes Conveying Fluid Based On Transfer Matrix Methods

With wide application of fluid-conveying pipe systems in naval architecture and ocean engineering, biological engineering, nuclear industry, chemical industry, aerospace industry and et al, so based on transfer matrix method, the author researches the fluid-solid coupled free vibration performance of fluid-conveying pipe in this paper.In the paper, the field transfer matrixes of fluid-conveying straight pipe?s transverse, axial and torsional vibrations are derived based on beam model, and then the author discusses the solutions of common components and boundary conditions, including elastic support, concentrated mass, external load and elbow. During the estabilishment of transfer matrix, friction coupling of pipe and fluid, Possion coupling and link coupling are mainly considered. Two main tasks are completed in the analysis of the free vibration of fluid-conveying pipes as following:(1) Through comparison between simulation results and modal analysis of fluid-conveying pipes with multi-span elastic support, the author concludes that transfer matrix method is feasible in this paper. On the base of this conclusion, the influence of elastic support stiffness on the vibration performance of fluid-conveying pipe, and the interaction between pipe and the fluid inside are investigated.(2) The calculated result of modal analysis of L-shape bending pipe is well anastomosed with that in references, which indicates the accuracy of the discrete model solution of elbow. And then the author analyzes the free vibration of elbow with different bending angles and the influence of link coupling at the bending location on the vibration performance of fluid-conveying pipe. Finally, the effect of element grid density on the result is investigated, which provides evidence for reduction of modal analytical program of the elbow.