ELSEVIER Journal of Wind Engineering

and Industrial Aerodynamics 67&68 (1997) 937

JOURNAL OF

Wind-induced response of double articulated towers

Suhail Ahmad, N. Islam, N.A. Siddiqui Department q[ Applied Mechanics, LL T., New Delhi 110 016, India

Abstract

Double hinged articulated off-shore towers are highly flexible against rotation at hinges and derive stability by means of their inherent large buoyancy. Their displace- ment response is mainly governed by rigid body mode of vibration at very low frequency, Emil Simiu's fluctuating wind velocity spectrum exclusively meant for compliant off-shore structures has been employed. This spectrum has high energy content in low-frequency region and, therefore, wind induces significant dynamic response of such towers. Hydrodynamic response due to surrounding waves becomes complex in the presence of wind. This paper deals with the investigation of structural behaviour due to random wind and wave environment. The Monte Carlo simulation technique is used to model this environment. Iterative time-domain solution proced- ure is adopted to take care of time-dependent parameters and nonlinearities. Stochas- tic response is characterised by Power Spectral Density Functions (PSDF) for various parametric combinations. Studies of wind effects are found to be imperative for double hinged articulated towers to serve and survive in the hostile off-shore environ- ment, dominated by high wind velocities.

0167-6105/97/$17.00 (~2 1997 Published by Elsevier Science B.V. All rights reserved. PII S0 1 67-61 05(97)00 1 34-7