engleski

Cumulative histeretic absorbed energy

Cumulative energy balance, during the earthquake action, defines the change of energies: potential, kinetic, dumping and hysteretic energy from the beginning to the end of earthquake action. Cumulative hysteretic energy at the end of earthquake time acting defines level of energy absorption done by structure. It presents the level of cumulative structural damage after the earthquake. Paper presents some results of, still active, project “ Seismic damage spectrum functions” . It is based on large number of non-linear structural response analysis to various earthquakes with different intensities and dominant frequencies as input load. In all of them structure were modelled as SDOF system. Results of provided analysis are structure response parameters: ductility, hysteretic energy and number of plastic excursions. All of them define post-elastic state of the structure. In this paper for the structures with constant dumping ratio 5% of critical and with varied parameters: basic periods from 0, 05s to 5 s, yield strength define by base shear of 0, 1G, 0, 3G and 0, 6G and post-elastic stiffness defined as elastic-plastic (K2=0) and as two bilinear functions with post-elastic stiffness degradation of 40% and 60% (K2=0, 4Ke and K2=0, 6Ke). Input seismic load are time-histories of real earthquake with maximum ground accelerations near 0, 1g, 0, 2g and 0, 4g which present earthquake levels given by codes (VII, VIII and IX zones of intensities). Results are present by spectrum curves.

Earthquake; Absorption; Energy; Spectrum; Regular structures.

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