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The purpose of this paper is to justify that it is necessary to take account of physical and mechanical properties of soil and different materials of erected structure for damping vibrations in dynamic loads; to suggest tools for modelling the damping effect (natural or engineering induced) between foundation and soil. Certain technique is suggested for modelling behaviour of structure in time history analysis with account of material damping. In the software, the damping effect is modelled in two variants: Rayleigh damping (for structure) and finite element of viscous damping. When solving this problem, the following results were obtained: physical meaning of material damping is described; Rayleigh damping coefficients were computed through modal damping coefficients. Numerical analysis is carried out for the structure together with soil in earthquake load using developed FE of viscous damping. Time history analysis was carried out for the problem. Peak values of displacement, speed and acceleration at the floor levels were compared. Analysis results are compared (with and without account of material damping). Significant influence of damping on the stress-strain state of the structure is confirmed. Scientific novelty of the paper is in the following: the damping effect is proved to happen regardless of the presence of installed structural damping equipment; technique for account of damping with Rayleigh damping coefficients is developed; new damping element is developed – FE of viscous damping (FE 62), its behaviour is described as linear mathematical model. Practical implications of the paper: developed technique and new FE enables the user to carry out numerical analysis properly and work out a set of measures on seismic safety for buildings and structures.
References  Alisjarbana S.W and Wangsadinata W. (2007): Dynamic Response of damped orthotropic plate on Pasternak foundation to dynamic moving loads. - Proceeding of ISEC-4, Melbourne, Australia, 1037-1041.  Fryba L. (1999): Vibration of solids and structures under moving loads. - Prague: Research Institute of Transport.  Gbadeyan J.A. and Dada M.S. (2001): The dynamic response of plates on Pasternak foundation to distributed moving loads. - Journal of Nigerian Mathematical Physics, vol.5, pp.185-200.  Gbadeyan J.A., Idowu A.S., Dada M.S. and Titiloye
proc. of International RILEM Conference on Dynamic Behavior of Concrete Structures , September, Expertcentrum TU Košice. Králik, J. and Cesnak, J. (2006) Experimental and numerical reliability analysis of damping devices under impact loads from container. In: First European Conference on Earthquake Engineering and Seismology. Abstract Book. 3-8 September, Geneva, Switzerland. pp. 256. Králik, J. (2009) Safety and Reliability of Nuclear Power Buildings in Slovakia. Earthquake - Impact - Explosion. Ed. STU Bratislava, 307 pp. Malý, J., Štepán, J., Schererová, K
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