09-10-2014, 02:12 PM
Ambient and low-level forced vibration tests are performed on a reinforced concrete (RC) moment resisting frame (MRF) building with unreinforced masonry (URM) infill walls to determine its dynamic properties namely, the fundamental translational and torsional natural periods, the corresponding mode shapes and the structural damping. This three-storey building lies in the seismic zone III of India as per the current code. An electrodynamics shaker, generating a maximum force of 133N, is used to apply a harmonic force at desired frequencies. This building is analytically modeled using the FEM package, STARDYNE. Four types of models are considered. The dynamic properties of the building as derived using these models, are compared with the experimentally obtained ones. The material properties used in the modelling, i.e., modulus of elasticity of brick masonry and reinforced concrete are determined by an in-situ experiment. It is found that the analytical model with a slit between the top of the infill wall and the suffix of the beam gave very good results for the vibrations