1421 KB40 KB199920252016Beer, MichaelKougioumtzoglou, Ioannis A.Mitseas, Ioannis P.Spanos, Pol D.letnik:62številka:nr. 7/8str. 440-451ISSN:0039-2480COBISSID_HOST:14745883URN:URN:NBN:SI:doc-Z7YN9FYGenZveza strojnih inženirjev in tehnikov Slovenije etc.Strojniški vestnikevolucijski stohastični procesinelinearna stohastična dinamikanelinearni/histerezni sistemiproblem prvega prehodastatistična linearizacijaverjetnost preživetjaNonlinear MDOF system survival probability determination subject to evolutionary stochastic excitation|An approximate technique for assessing the reliability of nonlinear multi-degree-of-freedom (MDOF) systems subject to a non-stationary stochastic excitation vector is developed. The proposed technique can be construed as a two-stage approach. First, relying on statistical linearization and utilizing a dimension reduction approach the nonlinear n-degree-of-freedom system is decoupled and cast into (n) effective single-degree-of-freedom (SDOF) linear time-variant (LTV) oscillators. Second, utilizing the effective SDOF LTV oscillator time-varying stiffness and damping elements in conjunction with a stochastic averaging treatment of the problem, the MDOF system survival probability and first- passage PDF are determined. Overall, the developed technique appears to be efficient and versatile since it can handle readily, at a low computational cost, a wide range of nonlinear/hysteretic behaviors as well as various stochastic excitation forms, even of the fully non- stationary in time and frequency kind. A 3-DOF system exhibiting hysteresis following the Bouc-Wen model is included in the numerical examples section. Comparisons with pertinent Monte Carlo simulations demonstrate the accuracy of the techniqueNaravne sile, ki vzbujajo dinamične sisteme, kot so npr. veter, valovi in seizmične obremenitve, so pogosto evolucijske narave. V takšnih pogojih se močno spreminja tako intenzivnost vzbujanj kakor tudi njihova frekvenčna vsebina. Ta razred strukturnih obremenitev je zato treba popisovati z nestacionarnimi stohastičnimi procesi. Močno vzbujani konstrukcijski sistemi lahko izkazujejo tudi značilno nelinearno vedenje s histerezami. Za skupnost, ki se ukvarja z dinamiko konstrukcij, je zato zelo pomemben razvoj tehnik za določanje odziva in vrednotenje zanesljivosti nelinearnih/histereznih sistemov, izpostavljenih evolucijskim stohastičnim vzbujanjemTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo