ELASTIC-PLASTIC STRAIN IN A FRAME PIPE SYSTEM UNDER WATER HAMMER LOADS: ANALYSIS AND PARAMETRIC SURVEY

摘要

This study deals with the dynamical characterisation of frame pipe under the effect of a water hammer transient. The constructed model consider the fluid-structure interaction and concerns both the elastic flexural and the elastic-plastic flexural behaviour of the pipe line configuration. A simple Prager oscillator represents the flexural motion of the system in the elastic and elastic-plastic field. The external load to this oscillator is the transient hydraulic.The mechanical equation representing the elastic-plastic motion of the oscillator is first exposed. The fluid-structure interaction are thus introduced and solved using the method of characteristic. Finally, The dynamical behaviour of the frame pipe in the uncoupled fluid-structure case is compared to the coupled fluid-structure case in the elastic and elastic-plastic fields. A parametric survey showing the influence of the geometrical and some mechanical parameters in the resulting plastic strain is proposed.