Effect of circular web openings on dynamic behaviour of cantilever steel thin-walled tapered I - beams

In this study, free and harmonic vibration analyses of cantilever steel thin-walled tapered beams without and with web openings are performed. The analyses are carried out based on finite element method with the help of ANSYS. SHELL 63 element is used for the analyses. Tapered I - beams with symmetric and un-symmetric cross-sections are considered. Initially, free vibration analysis is performed for tapered beams without and with circular web openings to find out the effect of web openings on natural frequencies. The free vibration analysis is then followed by the harmonic analysis. The peak amplitudes and corresponding frequency ranges are presented for the considered cases. Web tapered beam of symmetric cross-section with circular web openings resulted in maximum fundamental natural frequency on performing free vibration (modal) analysis and resulted in peak amplitude at higher frequency on performing harmonic analysis among the considered cases of beams with and without web openings. Thus web openings and type of cross - section affect the dynamic behaviour.