Analysis of Dynamic Fluid Pressure in Infinite Surface-mounted Pipelines with Arbitrary Cross Sectional Shapes induced by Seismic Waves Jong Myung Kim
ABSTRACT An analysis method of an infinite surface-mounted pipeline with an arbitrary cross sectional shape considering the dynamic fluid pressure induced by seismic waves is presented. The pipeline is modeled as an infinite and periodic Euler-Bernoulli beam. The wave-number response for bending moment of the pipeline is analyzed with transfer matrix and wave vector. The cross section of the pipeline and the fluid in the pipeline are modeled by finite elements and by boundary elements, respectively. To calculate dynamic fluid pressure, the coupled boundary element-finite element method is used. This pressure is considered as external force added on the pipeline. The moment of the pipeline decreases due to dynamic behavior of fluid while it increases due to deformation of the cross sectional shape. The dynamic behavior of fluid is dominant effect. However in view of the wave-number response function for bending moment, the effect of deformation is more significant than that of dynamic behavior of fluid, near the wave number corresponding to natural frequency of coupled mode. Therefore the dynamic behavior of fluid and the deformation of cross sectional shape of the pipeline must be considered to analyze the infinite surface-mounted pipeline.
Key Word Dynamic fluid pressure, infinite surface-mounted pipeline, coupled boundary element-finite element method, wave-number response function, steady-state response
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