Pregled savremenih seizmičkih analiza i načina uvođenja prigušenja u njima

Abstract

Autori rada su, na osnovu analize velikog broja naučnih radova, dali prikaz sopstvene originalne sistematizacije seizmičkih analiza konstrukcija, a veliki deo njih je razvijen u poslednje dve decenije. Seizmičke analize su klasifikovane generalno u dve (četiri) grupe: linearne i nelinearne statičke analize; i linearne i nelinearne dinamičke analize. Posebno su klasifikovane analize nelinearnog seizmičkog odgovora konstrukcija, a posebno analize ciljnog pomeranja kojim se definiše odnos seizmičkog zahteva i seizmičkog odgovora. S druge strane, klasifikacija je sprovedena i u funkciji da li se nelinearan odgovor sistema dobija primenom inkrementalno-iterativnih procedura ili primenom poluiterativnih i/ili poluinkrementalnih procedura. Nelinearne dinamičke analize su klasifikovane prema konceptu matematičke formulacije, odnosno da li se zasnivaju na samo jednoj dinamičkoj analizi, većem broju dinamičkih analiza ili dobijaju rešenja u kombinaciji s drugim metodama. Primenom sprovedene sistematizacije seizmičkih analiza može se vrlo efikasno razmotriti koji tip analize je optimalan za analizu konstrukcija i koji tip analize je potrebno uzeti u obzir u fazi preliminarnih i finalnih analiza za naučna istraživanja i stručne projekte. U radu su, takođe, prikazani aspekti modeliranja prigušenja u analizi konstrukcija sistematizacijom tipova prigušenja i formiranim dijagramima tokova, a u zavisnosti od tipa primenjene analize: linearne i nelinearne, statičke i dinamičke. Sistematizacija prigušenja je sprovedena prema načinu uvođenja u proračun i to preko prigušenja materijala, prigušenja elemenata veze i prigušenja koja se direktno uvode u analize, a koje se sprovode u kapacitativnom, vremenskom i frekventnom domenu. Primenom razvijenih dijagrama tokova, u procesu kreiranja numeričkih modela konstrukcija, može se vrlo efikasno razmotriti koji tip prigušenja treba odabrati i na koji način uvesti prigušenje u analizu konstrukcija. Takođe, primenom razvijenih dijagrama tokova mogu se definisati i alternativni pristupi uvođenja prigušenja u analizu konstrukcija.

The authors of the paper, on the basis of the analysis of a large number of scientific papers, presented their original systematization of seismic analyses of structures, where a large number of them were developed during the last twenty years. Seismic analyses are generally classified into two (four) groups: Linear Static Analyses (LSA) and Nonlinear Static Analyses (NSA), and Linear Dynamic Analyses (LDA) and Nonlinear Dynamic Analyses (NDA). The analyses of nonlinear seismic structural response were classified separately from the Target Displacement Analyses (TDA) which defines the relationship of the seismic demand and seismic response. On the other hand, classification was also conducted depending on whether a nonlinear response of the system is obtained by the implementation of incremental-iterative procedures or by implementation of semi-iterative and/or semi-incremental procedures. NDA were classified according to the concept of mathematical formulation, i.e. whether they are based on only one dynamic analysis, several dynamic analyses or they are solved in combination with other methods. By implementing the conducted systematization of seismic analyses, one can efficiently consider which type of analysis is optimal for structural analysis and which type of analysis should be taken into account in the phase of preliminary and final analyses in the course of scientific research and professional projects. This paper also presents the aspects of damping modelling in structural analysis through the systematization of damping types and flowcharts, depending on the type of analysis applied: linear and nonlinear, static and dynamic. Damping has been systematized based on the way it was introduced into calculations, i.e. over material damping, link element damping and damping directly introduced into the analyses which are conducted in capacitive, time and frequency domains. In the process of creating numerical structural models, the type of damping and the way of its introduction into structural analysis can be very efficiently selected by applying the flow charts developed. By applying the developed flowcharts, alternative approaches to the introduction of damping into structural analysis can also be defined.