Research On Performance Improvement Of Tuned Type Dampers

Structural vibration control technology is one of the hotspots in the civil engineering field. Tuned type dampers such as tuned mass damper (TMD) and tuned liquid damper (TLD) are the techniques with theory and practice. The hybrid tuned type dampers (HTTD), which replace the TMD mass by the structural additional facilities, are also used widely by their economy and practicability. However, there are several major problems for the tuned type dampers in the usage: sensibility to frequency for TMD, low sloshing mass and damping for TLD, affection of additional sloshing liquid in HTTD, etc. In view of this, improvement and innovation to the tuned type dampers will be carried out in this research, then the shaking table test will be done to validate the key parts of the research.The main contents of this research are listed as follows:1. The control performances of tuned liquid/mass damper (TLMD) and tuned liquid column/mass damper (TLCMD) are studied in this research. The phasic difference analyzing method is developed to discuss the dynamic characteristics of these two kinds of HTTD, and a optimized dynamic method is also developed to set HTTD for greater control effectiveness and saving the space of the inner structure.2. Two more practical HTTDs - tuned hybrid-tank/mass damper (THMD) and tuned double liquid columns/mass damper (TDLCMD) are developed based on the original HTTDs, then the phasic difference analyzing method is used to discuss the dynamic characteristics of these two new HTTDs and the optimized dynamic method is also used as the setting method for them.3. The tuning characteristics of TLMD and TLCMD are studied in this research. The control performance analyses are done under the perturbation of structural frequency, then the relationship between liquid sloshing phasic difference and the corresponding HTTD dimensions can be obtained under different structural frequency perturbation coefficients.4. Making use of the analyzed conclusions of the characteristics of TLMD and TLCMD, 4 controllable hybrid damper systems are developed in this research - controllable TMD-TLD hybrid system (CTTHS), controllable TMD-DTLCD hybrid System (CTDHS), controllable TMD-hybrid tank system of the first kind (CTHTS-Ι) and controllable TMD-hybrid tank system of the second kind (CTHTS-ΙΙ). Then the control strategies and control performances of these 4 new damper systems are studied in the research. 5. In order to improve the control performance of TLD, the tuned liquid damper embedded a transverse cylinder (TLDETC) is developed in this research. The sloshing mass, sloshing damping ratio and sloshing frequency of a TLDETC are formulated by using the fluid mechanics principle and energy method, then the comparison analysis of dynamic characteristics between TLDETC and ordinary TLD are made through three setting schemes to show that the damping characteristics, dynamic characteristics and control performance of a TLDETC outperforms an ordinary TLD.6. Based on the numerical simulation, a test modal of HTTD is designed, and the shaking table test is carried out for the first time in the HTTD series. The control performances of HTTD and TMD under diverse setting methods with a stable structural frequency are discussed to validate the dynamic characteristics of HTTD. Meanwhile, the control performances of HTTD and TMD under diverse setting methods with perturbed structural frequencies are also discussed to validate the tuning characteristics of HTTD and the control strategies of the controllable damper systems. At last, the discrepancies of the HTTD research between numerical simulation and test will be analyzed and some useful suggestion and discussion are also presented.