International Journal of Civil & Structural Engineering
Author(s) : HASSAN ABBA MUSA, INUWA IBRAHIM AMINU, SHUAIBU UMAR
The paradigm shifts in the history of predicting the wind related effects was shifted from early theoretical,numerical, experimental techniques, to Computer techniques in fully understanding the vibrational characteristics of a system like Bridge. Therefore, the structural dynamic analysis includes determination of the natural mode shapes and frequencies of an elastic structure in free unforced vibration. In this research paper, the software like ANSYS and others whose built based on Finite Element Method are adapted and well suited for this type of analysis since the mode shapes can be accurately derived from the geometrically complex of the structures, such as beams, and pylons sections that commonly found in slender structure like bridge. The FE structural model is typically formulated in SOLID-Works software as an Eigensystem,where the eigenvalues and eigenvectors represent the natural frequencies and the mode shapes, respectively. The lowest eigenvalues (1.1006e-008 Hz) correspond to the lowest characteristic frequencies of the physical system of Lekki Bridge and are typically more interesting than the higher modes simply because the physical system tends to experience the lower modes as dominant vibration frequencies.