Forced vibration test of pedestrian steel bridge using eccentric mass shaker

Abstract

The dynamic test has been performed on Jembatan Teksas, Universitas Indonesia. The purpose of the test was to obtain the dynamic parameters, which are the natural frequencies, the mode shapes, and the damping ratio. The test was conducted by applied forced excitation using an eccentric mass shaker. The dynamic responses were recorded using accelerometers and vibrometer during forced vibration state and a free vibration state. A comparison study was conducted through the 3D finite element analysis using SAP2000. The test could obtain five mode shapes of the bridge and the damping ratio. Close results were found between FE analysis and the test result. The average damping ratio obtained was 1.72% which was within the range of welding steel structures according to reference. Compared to the test conducted in 2011 and 2013, the bridge is in good condition which is indicated by its natural frequency where the current test decrease less than 2%.