000021986 001__ 21986
000021986 005__ 20170622131316.0
000021986 04107 $$aeng
000021986 046__ $$k2017-06-15
000021986 100__ $$aBlom, Anders
000021986 24500 $$aDEVELOPMENT OF AMPLIFIED SEISMIC RESPONSE SPECTRA FOR STRUCTURAL ANALYSIS OF DECOUPLED SMALL BORE PIPES

000021986 24630 $$n6.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000021986 260__ $$bNational Technical University of Athens, 2017
000021986 506__ $$arestricted
000021986 520__ $$2eng$$aIn various applications, not at least within the nuclear industry, piping systems are required to be structurally verified for seismic loads. Piping systems often have connected small bore pipes which also have requirements for seismic qualification. If the ratio of run-tobranch pipe moment of inertia is large, the small bore pipes can often be decoupled from the main pipes when performing the structural analysis. There are many reasons why decoupling is preferred in comparison to performing a coupled analysis. Firstly, from a project perspective, it is desirable to finish the design and verification of the main pipes before the work on the small bore pipes is started. Secondly, with decoupled pipes the analysis models become smaller, meaning reduced analysis time and reduced risk of encountering convergence difficulties for dynamic loads. Finally, decoupling the small bore pipes makes it possible to distinguish between primary and secondary loads, which will take away unnecessary conservatism in the evaluation of the small bore pipes. Though there are advantages of decoupling, the analyst will be faced with the question of how to consider the impact of the main pipe oscillations in the analysis of the small bore pipe. Seismic loads are generally applied to pipes as response spectrum loads derived in a seismic analysis of the supporting building structure. A clear disadvantage of a response spectrum analysis is that it only calculates bounds for forces, moments, displacements and accelerations and that it does not result in any frequency dependent quantities. There is no established industrial practice how the impact on the small bore pipe from the main pipe should be considered at the decoupling point and in many cases simplifications that give non-conservative results are made. This study presents a method to create an amplified response spectrum at the small bore piping connection point making use of modal analysis results and response spectrum input data. The method is validated by comparison with results from coupled analyses. The benefit of the proposed method is also demonstrated by applying it in evaluation of a small bore pipe.

000021986 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000021986 653__ $$aAmplified Response Spectrum, Decoupled Small Bore Pipes, Modal Analysis, Piping Analysis, Seismic Loads.

000021986 7112_ $$aCOMPDYN 2017 - 6th International Thematic Conference$$cRhodes Island (GR)$$d2017-06-15 / 2017-06-17$$gCOMPDYN2017
000021986 720__ $$aBlom, Anders
000021986 8560_ $$ffischerc@itam.cas.cz
000021986 8564_ $$s260080$$uhttps://invenio.itam.cas.cz/record/21986/files/18562.pdf$$yOriginal version of the author's contribution as presented on CD, section: [RS05] Dynamics of coupled problems
.
000021986 962__ $$r21500
000021986 980__ $$aPAPER