Basic Study on Vibrational Behavior of System Supporting Large-Scale Structures Subjected to Multiple Random Inputs Using Probabilistic Vibration Theory

Author(s):  
Atsuhiko Shintani ◽  
Keishi Tsujita ◽  
Tomohiro Ito ◽  
Chihiro Nakagawa

In this study, the vibrational behavior of a system supporting large-scale structures that are subjected to multiple random inputs is investigated based on probabilistic vibration theory. The analytical model (FEM) of a system that is subjected to white noise is constructed first. Pipings are assumed to be supported by a nonlinear elastoplastic damper. The vibrational behavior of the structures subjected to multiple random inputs is calculated via numerical simulations. After calculating the stress, energy absorption, etc., the dynamic reliability is calculated based on random theory. Finally, the effects of the supporting location and supporting capacity on the dynamic reliability are investigated.

Author(s):  
Atsuhiko Shintani ◽  
Keishi Tsujita ◽  
Tomohiro Ito ◽  
Chihiro Nakagawa

In this study, the vibrational behavior of piping systems supported by elasto-plastic dampers with gap supports was considered. First, an analytical model of L-type piping systems subjected to white noise was derived, including the nonlinear characteristics of the elasto-plastic dampers and gap supports. After the stress, energy absorption, and other parameters were calculated for many inputs, the dynamic reliability was calculated based on random theory. Optimization of the support locations was investigated. Finally, the effects of a gap support on the dynamic reliability were investigated.


1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.


2015 ◽  
Vol 12 (108) ◽  
pp. 20150044 ◽  
Author(s):  
Dervis C. Vural ◽  
Alexander Isakov ◽  
L. Mahadevan

Starting with Darwin, biologists have asked how populations evolve from a low fitness state that is evolutionarily stable to a high fitness state that is not. Specifically of interest is the emergence of cooperation and multicellularity where the fitness of individuals often appears in conflict with that of the population. Theories of social evolution and evolutionary game theory have produced a number of fruitful results employing two-state two-body frameworks. In this study, we depart from this tradition and instead consider a multi-player, multi-state evolutionary game, in which the fitness of an agent is determined by its relationship to an arbitrary number of other agents. We show that populations organize themselves in one of four distinct phases of interdependence depending on one parameter, selection strength. Some of these phases involve the formation of specialized large-scale structures. We then describe how the evolution of independence can be manipulated through various external perturbations.


2011 ◽  
Vol 418 (1) ◽  
pp. 214-229 ◽  
Author(s):  
Marco Baldi ◽  
Valeria Pettorino ◽  
Luca Amendola ◽  
Christof Wetterich

2012 ◽  
Vol 24 (5) ◽  
pp. 055112 ◽  
Author(s):  
Adrian Zenklusen ◽  
Simon Kuhn ◽  
Philipp Rudolf von Rohr

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