This studyaimsatevaluatingtheoptimalpropertiesoffrictionpendulumbearingstobeemployedfor the seismicprotectionofelasticisolatedstructuralsystemsunderearthquakeexcitationswithdifferent characteristicsintermsoffrequencycontent.Atwo-degree-of-freedommodelisconsideredtodescribe the isolatedsystembehaviorwhileaccountingforthesuperstructure flexibilityandanon-dimensional formulation ofthegoverningequationsofmotionisemployedtorelatethecharacteristicparameters describing theisolatorandstructurepropertiestotheresponseparametersofinterestfortheperfor- mance assessment.Seismicexcitationsaremodeledastime-modulated filteredGaussianwhitenoise random processesofdifferentintensitywithinthepowerspectraldensitymethod.The filter parameters control thefrequencycontentoftherandomexcitationsandarecalibratedtodescribestiff,mediumand soft soilconditions,respectively.Finally,multi-variateregressionexpressionsareobtainedfortheopti- mum valuesofthefrictioncoefficient thatminimizethesuperstructuredisplacementsrelativetothe base massasafunctionofthestructuralsystemproperties,oftheseismicinputintensityandofthesoil condition.
This study aims at evaluating the optimal properties of friction pendulum bearings to be employed for the seismic protection of elastic isolated structural systems under earthquake excitations with different characteristics in terms of frequency content. A two-degree-of-freedom model is considered to describe the isolated system behavior while accounting for the superstructure flexibility and a non-dimensional formulation of the governing equations of motion is employed to relate the characteristic parameters describing the isolator and structure properties to the response parameters of interest for the performance assessment. Seismic excitations are modeled as time-modulated filtered Gaussian white noise random processes of different intensity within the power spectral density method. The filter parameters control the frequency content of the random excitations and are calibrated to describe stiff, medium and soft soil conditions, respectively. Finally, multi-variate regression expressions are obtained for the optimum values of the friction coefficient that minimize the superstructure displacements relative to the base mass as a function of the structural system properties, of the seismic input intensity and of the soil condition.
Optimal design of friction pendulum system properties for isolated structures considering different soil conditions / Castaldo, Paolo; Ripani, M.. - In: SOIL DYNAMICS AND EARTHQUAKE ENGINEERING. - ISSN 0267-7261. - ELETTRONICO. - 90:(2016), pp. 74-87. [10.1016/j.soildyn.2016.08.025]
Optimal design of friction pendulum system properties for isolated structures considering different soil conditions
CASTALDO, PAOLO;
2016
Abstract
This study aims at evaluating the optimal properties of friction pendulum bearings to be employed for the seismic protection of elastic isolated structural systems under earthquake excitations with different characteristics in terms of frequency content. A two-degree-of-freedom model is considered to describe the isolated system behavior while accounting for the superstructure flexibility and a non-dimensional formulation of the governing equations of motion is employed to relate the characteristic parameters describing the isolator and structure properties to the response parameters of interest for the performance assessment. Seismic excitations are modeled as time-modulated filtered Gaussian white noise random processes of different intensity within the power spectral density method. The filter parameters control the frequency content of the random excitations and are calibrated to describe stiff, medium and soft soil conditions, respectively. Finally, multi-variate regression expressions are obtained for the optimum values of the friction coefficient that minimize the superstructure displacements relative to the base mass as a function of the structural system properties, of the seismic input intensity and of the soil condition.Pubblicazioni consigliate
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https://hdl.handle.net/11583/2664973
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