tailieunhanh - Spectral proper transformation and application to gust response prediction of structures

This paper will present the proper ort hogonal decomposition using the spectral proper transformation in the frequency domain to decouple the multi-variate turbulent loading processes. New approach in t he gust response prediction of structures will be formul ated with numerical example of cable-stayed bridge. | Vietnam Jo urnal of Mechanics, VAST, Vol. 29, No. l (2007) , pp. 25 - 36 SPECTRAL PROPER TRANSFORMATION AND APPLICATION TO GUST RESPONSE PREDICTION OF STRUCTURES LE THAI HOA Wind Engineering Laboratory, Graduate S chool of Engineering, Kyoto University, Japan NGUYEN DONG ANH Institut e of Mechanics, VAST A bst r act. Random turbulent loading on engineering structures which immersed in the atmospheri c turbulent flow is often represented as the multi-dimensional and / or mul Livariate Gaussia n random loading processes . Gust res ponse prediction, however , usua lly burdens a lot of computational difficulties due to turbulent loading proj ection on the generalized structural coordinates. In these cases, the decomposition techniques must be required to decouple t he mul t i-variate tu rbulent load ing into t he independentl y generalized turbulent fo rces, t hen is associated with t he general ized structural modes . Th is paper will present the proper ort hogonal decomposition using t he spectral proper transform ation in the fr equency domain to decouple t he mu lti-variate tur bul ent loadin g processes. New approach in t he gust response prediction of structures will be formul ated with numerical example of cable-stayed bridge. 1. INTRODUCT ION Gust response prediction of structures subj ected to the turbulent -induced forces in the atmospheric turbulent flow requires as a must among wind effects and wind-induced vibrations. General formul at ion of gust response prediction of line-like struct ures has proposed by Davenport [6]. As a principle, the multi-degree-of-freedom (MDOF) motion equations of structures were decomposed orthogonally in the generalized coordinates and vibrational mode shapes tha nks to the structural modal transformation (S MT). However, there were inevitable difficulti es to generalize external turbulent forces, whi ch t hen are associated with generalized coordinates . So far, the joint acceptance function (JAF) has been applied to .