...Akira Maekawa; Tsuneo Takahashi This study describes inelastic seismic design of piping systems considering the damping effect caused by elastic–plastic property of a pipe support which is called an elastic–plastic support. Though the elastic–plastic support is proposed as inelastic seismic design...

... excitations, an analytical model called the multiple yield and bounding surfaces model is proposed. On the basis of the derived mathematical formulations for simulation of the characteristics of the Multiple DO-FPS isolation bearing, it is revealed that the natural period and damping effect of the Multiple DO...

...M. Utsumi This paper investigates the use of dynamic vibration absorbers as a means to reduce the vibration of a floating roof due to sloshing caused by long-period earthquakes. It is shown that the damping ratio of the primary system caused by the dynamic vibration absorbers increases with rising...

...M. Utsumi This paper investigates a variational method for theoretically determining the first damping ratio of sloshing in cylindrical and arbitrary axisymmetric tanks. In this method, a virtual work expression for the viscous terms in the Navier–Stokes equations is transformed into the first-mode...

...M. J. Pettigrew; R. J. Rogers; F. Axisa This paper addresses the question of damping of multispan heat exchanger tubes with liquids (mostly water) on the shell side. The different energy dissipation mechanisms that contribute to damping are investigated. The available experimental data from...

... on the effect of varying the flexibility angle. At the same time, the model sheds some light on the role played by the flexibility angle in determining the overall fluid-structure damping underlying the observed stability behavior. The effect of varying flow direction on fluidelastic instability was studied...

... forces that are used to calculate added damping and stiffness coefficients employed with the UFM. The investigation demonstrates that the UFM utilized in conjunction with CFD is a viable approach for calculating the stability map for a given tube array. The FEI was predicted for in-line square and normal...

...Marwan Hassan; Achraf Hossen This paper presents simulations of a loosely supported cantilever tube subjected to turbulence and fluidelastic instability forces. Several time domain fluid force models are presented to simulate the damping-controlled fluidelastic instability mechanism in tube arrays...

... and pipe breakages. This paper examines the conditions that give rise to the large noise levels. These conditions, for the occurrence of noise, are investigated using an eigenvalue approach, which involves the effect of damping due to losses from the pipe boundaries and pipe friction. The investigation...

... fractions and mass fluxes. Fluidelastic instabilities, random turbulence excitation, and damping were investigated. The results were compared with those obtained for a similar tube bundle tested in an air-water cross flow and to those for a rotated triangular bundle similarly tested in Freon. Vibration...

...John Mahon; Craig Meskell The interaction between acoustic resonance and damping controlled fluidelastic instability (FEI) in a normal triangular tube array ( P ∕ d = 1.32 ) has been investigated. The duct acoustics were excited with speakers placed adjacent to the tube array to artificially...

... structural characteristics and fluid-elastic effects due to the presence of the dense medium in the space between cylinders, followed by a forced-vibration analysis. It is shown here that the out-of-phase fluid-elastic effects (added damping) are dependent on the position of cylinders within the bundle...

... of the excitation increases. The damping ratio with the bulkhead is much larger than that without the bulkhead. The damping generated by the bulkhead depends on the amplitude of the excitation. The flow pattern plays an important role in the dissipation of the energy of the sloshing. In particular, the vortices...

... stress is related to a vibration equation for a suddenly applied load. Consideration of structural and fluid damping, as well as pipe constraints at the end of the pipe, were considered in the derivation of the vibration equations. In short, vibration equations are presented in this paper...

... were modeled for an 8 NPS pipe, using ABAQUS ® . For either material, the maximum stress was seen to be equal when damping was neglected. At the time the maximum stress occurred, the hoop stress was equivalent to twice the stress that would be expected if an equivalent static stress was applied...

... into account coupling between the solid tube and surrounding fluid at the borehole/expanded tube annulus, as well as the damping effect on tube structural response. The paper also conducts a comparative study aiming at studying the post-expansion tubular fluid response and identifying the different features...

... in which motion of auxiliary mass is limited by motion-limiting stop or placed inside a container. In this paper, in order to consider energy loss for an impact represented by the coefficient of restitution and duration of collision, an analytical model with hysteresis damping is introduced. Using...

... with and without EPD on shaker table. Using a finite element model of the piping systems, linear and nonlinear time-history analysis is carried out using Newmark’s time integration technique. Equivalent linearization technique, such as Caughey method, is used to evaluate the equivalent damping of the piping...

..., the various parameters that could affect the seismic structural response have been identified as material strength of concrete, structural damping available within the structure, and the normalized ground motion response spectral shape. Based on this limited case study, the seismic fragility of the structure...

...M. J. Pettigrew, Fellow ASME; C. E. Taylor Two-phase flow exists in many shell-and-tube heat exchangers such as condensers, evaporators, and nuclear steam generators. Some knowledge on tube damping mechanisms is required to avoid flow-induced vibration problems. This paper outlines the development...