A. Vimuttasoongviriya, N. Kwatra, M. Kumar
It is necessary to monitor the damage of structure both original and retrofitted frame in high seismic region. The information in the change of structural dynamic is always utilized to make decisions on maintenance of damaged structure. This paper investigates the effect of lateral quasi-static load on damage indexes based on modal parameters damage method. The three story reinforced concrete (RC) frame model was constructed and tested under different controlled damage. The damaged frame was repaired by using Glass Fiber Reinforced Polymer (GFRP) laminate. The modal plastic softening method, stiffnessmass ratios method and modal flexibility method and frequency response function (FRF) based mode shape method were used to calculate damage indexes of the experiment. Results of this study show that the damage indexes of retrofitted frame reduce indicating better performance as compared to the control frame. Damage index based on the change in FRF shows a much acceptable accuracy correlation with damage based on the change in natural frequency and mode shape in present work.
 V. Kanwar, N. Kwatra, P. Aggarwal, M.L. Gambir, Vibration Monitoring of a RCC Building Model, Proceedings of National Conference on Technology for Disaster Mitigation, Hamirpur, India (2006), pp. 277-285.  H. Estekanchi, K. Arjomandi, Comparison of damage indexes in nonlinear time history analysis of steel moment frames, Asian Journal of Civil Engineering, Vol.8, No.6 (2007), pp. 629-646.  A. Mukherjee, M. Joshi, FRPC reinforced concrete beam-column joints under cyclic excitation, Composite Structures, Vol.70 (2005), pp. 185-199.  Y.J. Park, A.H-S. Ang, Seismic damage analysis of RC buildings, Structural Engineering ASCE, Vol.ST4-111 (1985), pp. 740-757.  A. Vimuttasoongviriya, N. Kwatra, M. Kumar, Effect of lateral quasi-static load on nonlinear behaviour and damage indexes of retrofitted RC frame model, Asian Journal of Civil Engineering, Vol.10, No.5 (2009), pp. 563-588.  A. Vimuttasoongviriya, N. Kwatra, M. Kumar, Nonlinear Behaviour and Vibration Based Damage Identification of Retrofitted RC Frame Model, in D. editor, Proceeding of High Rise Towers and Tall Buildings 2010, Munich, Germany, 2010 April 14-16, HTTB (2010), pp. 184-185.  E. Dipasquale, A.S. Cakmak, Seismic damage assessment using linear models. Soil Dynamics and Earthquake Engineering, Vol.4, No.9 (1990), pp. 194-215.  R. Rodriguez, L.R. Barroso, Stiffness-Mass Ratios Method for Baseline Determination and Damage Assessment of a Benchmark Structure, Proceedings of the American Control Conference Anchorage, AK, USA (2002), pp. 2469-2474.