Dynamic Response of Multi Storey Building Frame under Harmonic Excitation

Abstract

The strong movement caused by a seismic event causes structural damage to a building. Buildings are designed for gravity, and thus are usually sufficiently designed for vertical movement. Earthquake forces act similarly to sound waves, produced at different frequencies and at different amplitudes. A three storied building frame model subjected to harmonic motions is studied. The frame is rectangular in plan consists of four steel columns and four steel slabs, each attached to the columns at regular interval. The objective is to understand the response behavior of the frame under known input excitation while realizing the occurrence of resonance phenomenon in multi degree-of-freedom systems. Upon completion of the model, free vibration tests are performed to determine the actual properties of the model such as stiffness, damping ratio, and natural frequencies of vibration. Shake table is used for excitations and corresponding response of the physical model is measured in terms of amplitude, natural frequency, resonance frequency, acceleration, mode Shape. The experimental results are compared with Ansys software. Keywords: Dynamic response of building, S hake table Testing, Stiffness, Damping, Frequency and Mode shape.