000013090 001__ 13090
000013090 005__ 20161114160327.0
000013090 04107 $$aeng
000013090 046__ $$k2009-06-22
000013090 100__ $$aBarbato, M.
000013090 24500 $$aTime-variant spectral characteristics of nonstationary random processes: an application to structural reliability and earthquake engineering

000013090 24630 $$n2.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013090 260__ $$bNational Technical University of Athens, 2009
000013090 506__ $$arestricted
000013090 520__ $$2eng$$aIn this paper, the spectral characteristics of non-stationary random processes are applied to the time-variant first passage problem in structural reliability. The first passage problem consists in computing the probability of a response quantity exceeding a deterministic threshold in a given interval of time when the parameters defining the structural system and/or the loading are random quantities. The Vanmarcke and modified Vanmarcke approximations of the failure probability are expressed as integrals in time of the closed-forms of the corresponding hazard functions. These closed-forms refer to linear elastic systems subjected to a time-modulated coloured noise base excitation and are obtained using the closed-form solutions for the time-variant bandwidth parameter. These approximate solutions to the first passage problem are compared with the classical Poisson approximation and Monte Carlo simulation results for an idealized linear elastic model of a three-story one-bay shear-type steel building. The retrofit of this benchmark structure with viscous dampers is also considered, allowing (1) to illustrate the use of the newly available closed-form approximations of the failure probability for non-classically damped linear elastic systems, and (2) to show an example of practical use in structural engineering of the presented analytical derivations. The earthquake base excitation is modelled as a filtered white noise process defined by the well-known Kanai-Tajimi equation and time-modulated by the widely-used Shinozuka and Sato modulating function. The failure condition is expressed in terms of interstory drifts outcrossing specified deterministic thresholds. The results presented in this study show that the two Vanmarcke approximations can improve considerably the estimates of the failure probability for the first passage problem when compared with the simpler Poisson approximation.

000013090 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013090 653__ $$aSpectral Characteristics, Stochastic Processes, Time-Variant Failure Probability, Poisson Approximation, Vanmarcke Approximation, Structural Reliability, Earthquake Engineering. Abstract. In this paper, the spectral characteristics of non-stationary random processes are applied to the time-variant first passage problem in structural reliability. The first passage problem consists in computing the probability of a response quantity exceeding a deterministic threshold in a given interval of time when the parameters defining the structural system and/or the loading are random quantities. The Vanmarcke and modified Vanmarcke approximations of the failure probability are expressed as integrals in time of the closed-forms of the corresponding hazard functions. These closed-forms refer to linear elastic systems subjected to a time-modulated coloured noise base excitation and are obtained using the closed-form solutions for the time-variant bandwidth parameter. These approximate solutions to the first passage problem are compared with the classical Poisson approximation and Monte Carlo simulation results for an idealized linear elastic model of a three-story one-bay shear-type steel building. The retrofit of this benchmark structure with viscous dampers is also considered, allowing (1) to illustrate the use of the newly available closed-form approximations of the failure probability for non-classically damped linear elastic systems, and (2) to show an example of practical use in structural engineering of the presented analytical derivations. The earthquake base excitation is modelled as a filtered white noise process defined by the well-known Kanai-Tajimi equation and time-modulated by the widely-used Shinozuka and Sato modulating function. The failure condition is expressed in terms of interstory drifts outcrossing specified deterministic thresholds. The results presented in this study show that the two Vanmarcke approximations can improve considerably the estimates of the failure probability for the first passage problem when compared with the simpler Poisson approximation.

000013090 7112_ $$aCOMPDYN 2009 - 2nd International Thematic Conference$$cIsland of Rhodes (GR)$$d2009-06-22 / 2009-06-24$$gCOMPDYN2009
000013090 720__ $$aBarbato, M.
000013090 8560_ $$ffischerc@itam.cas.cz
000013090 8564_ $$s639780$$uhttps://invenio.itam.cas.cz/record/13090/files/CD119.pdf$$yOriginal version of the author's contribution as presented on CD, section: Statistical and probabilistic methods in computational mechanics to treat aleatory and epistemic uncertainties in structural and/or geotechnical systems and their loading environment - i (MS).
000013090 962__ $$r13074
000013090 980__ $$aPAPER