Response of guyed offshore towers to stochastic loads: Time domain vs frequency domain

• Published in: Engineering structures Vol. 10; no. 2; pp. 106 - 116
• Main Authors: Brynjolfsson, S., Leonard, J.W.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1988
• Subjects: dynamic loads; guyed offshore towers; guyed towers; loading; Marine; mathematical models; mooring lines; nonlinear equations; nonlinearity; offshore structures; stochastic loads; stochastic processes; guyed offshore towers; nonlinearity; stochastic loads
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/0141-0296(88)90036-3

The validity of the widely used stochastic linearization method for analysing the response of guyed towers to stochastic loads is investigated. The governing equation of a guyed tower has two sources of nonlinearities: fluid-structure interaction and the restoring force of the cables. In this study, a linearized single degree of freedom model of a guyed tower is developed using stochastic linearization approach. It is solved in the frequency domain, giving the statistical response of the guyed tower. The results are compared to the response statistics of a time simulation that fully incorporates the nonlinearities of the cable system and the fluid-structure interaction. It is found that the results from the linearized model agree reasonably well with the results from the time simulation of the fully nonlinear system. The computer time using the stochastic linearization approach is several orders of magnitude less than for a conventional time simulation method. It is therefore justifiable to use this method in the early design stages of guyed towers.