Parametric Optimization Of Viscoelastic Dampers In Vibration Control Of Space Frame Structures

Based on the optimal design theory in engineering structures, this thesis presents two optimal methods, i.e. complex method and the method of fmincon function, and investigates their application to the vibration control of space frame structures. First of all, the state-of-the-art researches of vibration control technologies in long-span spatial structures as well as an overview of the applications of structural optimal design to civil engineering are summarized. Then, the complex method and the method of fmincon function are selected as the tools of optimization, and the program of an example for structural optimization is made to demonstrate the two optimal algorithms'validity. According to the two algorithms, the parametric optimization of viscoelastic dampers in the vibration control of a single degree of freedom(SDOF) system is studied, and the feasibility of the two algorithms to structural control is also discussed. Finally, the complex method is used to conduct the parametric optimization of viscoelastic dampers in the vibration control of space frame structures. Several control objective functions of parametric optimization are developed, and the parametric optimization of the dampers is discussed by utilizing the complex method in the given constraint and boundary conditions. Besides, the optimum installation of the viscoelastic dampers for space frames is analyzed, and fundamental optimal steps for adding viscoelastic dampers to practical structures and corresponding strategies are advised. The results of this thesis show that complex method is feasible and effective to optimize dampers'parameters in the vibration control of long-span spatial structures.