000009551 001__ 9551
000009551 005__ 20141205150217.0
000009551 04107 $$aeng
000009551 046__ $$k2008-10-12
000009551 100__ $$aBlázquez, Rafael
000009551 24500 $$aTime-Domain Response of Simple Elastic Systems to Seismic Motion: Error Assessment and Engineering Implications

000009551 24630 $$n14.$$pProceedings of the 14th World Conference on Earthquake Engineering
000009551 260__ $$b
000009551 506__ $$arestricted
000009551 520__ $$2eng$$aTime-stepping methods and/or direct evaluation of Duhamel’s integral are being increasingly used in earthquake engineering to solve the equations of motion for discrete and continuous systems, due to affordable computational costs, applicability to linear and non linear oscillators and permanent growth of the world data base of earthquake acelerogramas. Yet, when applying the above methods, one must be aware that all integration schemes, regardless of their stability and convergence characteristics, act as digital recursive filters that distort unevenly the frequency content of the input, and this may result in a misleading response of the system. Furthermore, in practice, the initial conditions for the computation of the response, in the case of analog excitations that have lost the initial portion of motion, are unknown and assumed to be zero for calculation purposes. This assumption, rigorously speaking, is only valid for high-frequency systems, (e.g., rigid structures), and leads to unconservative designs for long-period systems if the initial condition effects are not properly taken into account. In this paper a rational criterion is presented to rank the accuracy of various commonly used integration procedures for the dynamics of soil and/or structural systems. A few examples are shown to compare the performance of the methods and their sensitivity to the factors controlling the integration error, namely, the amplitude of the time step, the variation of the motion values between sampling points, and the dynamic properties of the vibrating system. The above question is of primary interest for short-to-intermediate period elastic systems, which are governed by the transient phase of the seismic response. For long period systems, which are governed mainly by the free-vibration part of the response, the study clearly shows large magnifications of the computed “non resting” response spectra with respect to the conventional calculations.

000009551 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000009551 653__ $$aTime-integration algorithms, linear oscillators, transfer functions, initial conditions, response spectra, long-period systems.

000009551 7112_ $$a14th World Conference on Earthquake Engineering$$cBejing (CN)$$d2008-10-12 / 2008-10-17$$gWCEE15
000009551 720__ $$aBlázquez, Rafael
000009551 8560_ $$ffischerc@itam.cas.cz
000009551 8564_ $$s1936380$$uhttps://invenio.itam.cas.cz/record/9551/files/K001.pdf$$yOriginal version of the author's contribution as presented on CD, Paper ID: K001.
000009551 962__ $$r9324
000009551 980__ $$aPAPER