000019955 001__ 19955
000019955 005__ 20170118182348.0
000019955 04107 $$aeng
000019955 046__ $$k2017-01-09
000019955 100__ $$aNaprstek, Jiri
000019955 24500 $$aPlanar Compress Wave Scattering and Energy Diminution Due To Random In-Homogeneity of Material Density

000019955 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019955 260__ $$b
000019955 506__ $$arestricted
000019955 520__ $$2eng$$aSlender engineering structures are endangered by a surface seismic wave. Subsoil parameters include a significant random inhomogeneity, which strongly influences character, spectral composition and intensity of such waves. Therefore, the seismic shock in a certain distance from the epicenter changes its degree and type, depending on a random character of the subsoil parameters in the positive but also in the negative meaning of the term. The paper investigates the compress wave propagation in two-dimensional continuum, the density of which is a continuous random function of x,y coordinates. This basic concept refers materials with in-homogeneity, which are encountered in subsoil being attacked by seismic wave. The random in-homogeneity influences significantly the wave structure and energy diffusion due to scatter at in-homogeneities. The density consists of a constant mean value and density fluctuations. Relevant centered two-dimensional random process is considered to be Gaussian, stochastically homogeneous and ergodic in x,y coordinates. The integral spectral decomposition in space is employed to derive the governing integro-differential system. It includes unknown deterministic component of the response and functions characterizing its random part. An approximate supposition that Gaussian imperfections lead to non-centered Gaussian response is adopted. There is shown a steep drop of the response deterministic part and a simultaneous increase of the response uncertainty (stochastic part) with raising distance from the point of excitation. These processes don't represent any mechanical energy loss, but only changes of its form. An upper limit of the excitation frequency (critical frequency) depending predominantly on the mean correlation length of imperfections has been found. Some ideas of application in earthquake engineering are given.

000019955 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019955 653__ $$aWave propagation, Material random in-homogeneity, Energy random scattering.

000019955 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019955 720__ $$aNaprstek, Jiri$$iFischer, Cyril
000019955 8560_ $$ffischerc@itam.cas.cz
000019955 8564_ $$s395817$$uhttps://invenio.itam.cas.cz/record/19955/files/48.pdf$$yOriginal version of the author's contribution as presented on USB, paper 48.
000019955 962__ $$r16048
000019955 980__ $$aPAPER