Abstract:
Vibration control is an important issue for structures subjected to dynamic loading like earthquake and wind. It is necessary to keep structural response within desirable limit and achieve desirable performance of structures. Among different structural control techniques Tuned Mass Damper (TMD) is a popular and good practical option because of its simple principle and easier implementation on existing buildings with comparatively modest rehabilitation. Appropriate selection of damper parameters is required for the structural system to perform efficiently. In the present study a methodology has been developed to optimize Multiple Tuned Mass Damper (MTMD) parameters considering soil-structure interaction. A global optimization algorithm named Evolutionary Operation (EVOP) has been applied for optimization. Generalized equation of motion has been proposed for building frames with any number of stories associated with any number of Tuned mass Damper (TMD) at different story level subjected to seismic excitation. A computer program has been developed in C++ to analyze Structure-TMD system for optimization problem formulation and has been linked with EVOP. In the optimization problem optimization criterion is defined as minimization of top displacement and maximum inter-story drift. The study has been conducted to explore EVOP in vibration control of structures using TMD. EVOP is found effective in minimizing structural performance with higher percentage of reduction in sway and choice of smaller TMD parameters. Also different combinations of TMDs have been optimized for regular and irregular frames to minimize top displacement and maximum inter-story drift in two different optimization problems. It is found possible for TMDs to minimize structural response even if bottom story stiffness is less. Optimum TMD parameters vary with the irregularity of structural system. Finally, Soil-Pile interaction has been modeled using a program TLEM (Thin Layered Element Method) for different soil-pile systems. Later soil-pile interaction has been incorporated into superstructure and optimization has been performed. The result shows, excluding the SSI effect in optimization overestimates the TMD’s performance.
