Influence of test conditions on modal characteristics of reinforced concrete structures under different damage scenarios

In the present work, studies are carried out on experimental modal analysis of reinforced concrete structural members for damage assessment using linear and nonlinear vibration characteristics at different levels of damage. Parameters such as support conditions, type and level of excitation etc. are found to have prominent influence on vibration characteristics. Experimental investigations have been carried out to estimate the influence of these parameters on the vibration characteristics of reinforced concrete structures. Based on the investigations using different excitation mechanisms, it is noted that resolution of modal responses in the case of burst random is much better when compared to true random excitation. The excitation type and force levels are found to have considerable influence on vibration characteristics. It is opined that judicious selection in using the type of excitation, level of excitation force plays important role especially when evaluating the vibration characteristics of reinforced concrete structures for damage assessment.