Study And Optimization On Vibration Absorption Effect Of Mega-frame Structures With Vibration Absorption Substructure

A novel structural system develops from partially changing substructures of the mega-frame structures, which is composed of a mega-frame and a number of substructures, to the vibration reduction substructures has been put forward in this research. Isolation bearings are placed between columns of substructures and the mega-frame beams, and energy-dissipating dampers between substructure beams and the mega-frame columns. Then the vibration reduction substructure works as a TMD with a massive mass. The vibration reduction substructures achieve a significant vibration reduction effect.. Based on the Theme of National Natural Science Foundation of China (Research on Seismic Energy and Collapse Analysis of Super High-Rise Mega-frame Structures with Vibration-Absorption" and "Study on the Seismic Behavior and Earthquake Resilience of the Mega-frame with Vibration Reduction Substructure"), the effect of the number and layout of the vibration reduction substructure, damping coefficient ratio, frequency ratio on the vibration reduction behavior of mega-frame was analyzed through the combination of simplified model and finite element model with the aim of optimization. The main conclusions are shown as follows:(1) In order to conduct a preliminary research and optimization on the vibration absorption effect of mega-frame structures with vibration absorption substructure. Simplified model was proposed and parameter analysis was conducted. The results indicated that vibration reduction can be achieved when the frequency ratio is between 0.6 and 1.2. The best vibration reduction occur when frequency ratio is 0.96. For the mega-frame structures with more than one vibration absorption substructure, the vibration reduction performance can be enhanced by adding the number of the substructures. And the robust of the vibration reduction can also be enhanced.(2) In order to conduct a further research on the vibration absorption effect of mega-frame structures with only one vibration absorption substructure. Finite element model was proposed and parameter analysis was conducted. The effect of the damping coefficient ratio, frequency ratio on the vibration reduction behavior of mega-frame was analyzed. The results indicated that the vibration reduction is affected be the duration of the seismic wave. The vibration reduction can only be occurred in the seismic wave with long duration.(3) Through the comparison of the result between finite element model and simplified model, it can be found that the result from simplified model agree well with the finite element model. The usability and rationality of the simplified model was validated.(4) In order to study on the vibration absorption effect of mega-frame structures with only one vibration absorption substructure under elastic-plastic condition, constitutive model of ABAQUS was developed and the elastic-plastic finite element model was validated. Based on the validated model, the vibration absorption effect of the structure was analyzed. The results indicated that in the elastic-plastic condition, the vibration reduction performance is decreased because of the damage.(5) The design method of "Analysis of simplified model→ Analysis of elastic finite element model→ Analysis of elastic-plastic finite element model" can provide reference for the optimization of mega-frame structures with vibration absorption substructure.