The design of complex structures like Offshore Wind Turbines (OWTs) is commonly based on the results of deterministic structural analyses, carried out on finite element models of the structural system. However, the assessment of the structural response is affected by significant uncertainties, due to the random variability of both the environmental actions and the geometric and mechanical properties of the structure. An efficient procedure to deal with the uncertainty of modeling and loading parameters requires the characterization of the probability distribution functions of the parameters of the models of the actions and structural response, and the assessment of the probability distributions of the response parameters. Neglecting pertinent sources of uncertainty can lead to an incorrect evaluation of the stochastic structural response, and to an improper risk assessment. This paper focuses on the effects on the structural response of an OWT induced by the uncertainty of the parameters used to describe the environmental actions and the finite element model of the structure (referred to as the modeling parameters). A proper probability characterization of the parameters is assumed, and the relevance and the propagation of the uncertainty to the response are investigated. Reference is made to an OWT with a jacket support structure. Analyses are carried out in frequency domain by adopting a linear elastic finite element model, and the response uncertainty is estimated by using a sampling technique. The results presented in this paper are considered useful for the preliminary design phase, where upper and lower bounds of the stochastic structural response have to be estimated in order to select the design configuration. © 2010 ASCE.
Effects of Modelling Parameter Uncertainty on the Structural Response of Offshore Wind Turbines / M., Barbato; Ciampoli, Marcello; Petrini, Francesco. - CD-ROM. - articolo in CD-ROM:(2010), pp. 2027-2038. (Intervento presentato al convegno Earth and Space 2010 tenutosi a Honolulu; United States nel 14 – 17 Marzo 2010) [10.1061/41096(366)185].
Effects of Modelling Parameter Uncertainty on the Structural Response of Offshore Wind Turbines
CIAMPOLI, Marcello;PETRINI, Francesco
2010
Abstract
The design of complex structures like Offshore Wind Turbines (OWTs) is commonly based on the results of deterministic structural analyses, carried out on finite element models of the structural system. However, the assessment of the structural response is affected by significant uncertainties, due to the random variability of both the environmental actions and the geometric and mechanical properties of the structure. An efficient procedure to deal with the uncertainty of modeling and loading parameters requires the characterization of the probability distribution functions of the parameters of the models of the actions and structural response, and the assessment of the probability distributions of the response parameters. Neglecting pertinent sources of uncertainty can lead to an incorrect evaluation of the stochastic structural response, and to an improper risk assessment. This paper focuses on the effects on the structural response of an OWT induced by the uncertainty of the parameters used to describe the environmental actions and the finite element model of the structure (referred to as the modeling parameters). A proper probability characterization of the parameters is assumed, and the relevance and the propagation of the uncertainty to the response are investigated. Reference is made to an OWT with a jacket support structure. Analyses are carried out in frequency domain by adopting a linear elastic finite element model, and the response uncertainty is estimated by using a sampling technique. The results presented in this paper are considered useful for the preliminary design phase, where upper and lower bounds of the stochastic structural response have to be estimated in order to select the design configuration. © 2010 ASCE.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.