An efficient method for selection of vibration modes contributory to wind response on dome-like roofs

A simple and efficient method has been proposed for selection of vibration modes, which dominantly contribute to responses on dome-like curved roofs, when a mode-superposition method is adopted. The criteria consists of the three points. First, it is proposed to make an efficient selection of dominant modes from the view point of contribution to the expected fluctuating strain energy of the system. Second, it is pointed out that there exists a specific mode, which is indispensable to estimate wind responses, even though its natural frequency or modal order may be very high. This specific mode is named the "X-mode" because it is likely to be overlooked because of its higher position of modal order, in spite of its significance to wind responses. Third, in order to overcome the anticipated difficulty of finding the true "X-mode", a practical method is presented to constitute a "quasi-X-mode" approximately. The effectiveness of the proposed method is verified through a numerical simulation of the wind response of a spherical dome. (C) 1998 Elsevier Science B.V. All rights reserved.