| Ordinary friction energy dissipater has simple structure, stable performance. Butonce installed to the structure, its friction cannot adjust, and adaptability is poor.Piezoelectric ceramic actuator has the advantages of fast response, small energyconsumption and large output, but driving displacement is small, not suitable for directeffects on the structure. Fuzzy control is based on fuzzy set and fuzzy language rules,and determines the control rules according to expert experience or site operatorexperience knowledge and operational data. It can realize effective control to anonlinear and time-varying object without establishing a precise mathematical model.But the traditional fuzzy control is mainly rely on control experts and operatorsexperience knowledge to establish fuzzy control rules, whoes system generally are morecomplex nonlinear function. And perfect control rules are difficult to set up when theexpert experience is lack. The adaptive fuzzy control based on analytic expression onlyconsiders the realization of the fuzzy control rules from the function form, gets rid ofthe reliance to expert experience when built control rules, and has strong adaptabilityand better control effect. With the output performance of piezoelectric friction damperand fuzzy control theory as a foundation, the article is mainly for the following researchwork.(1) Combining the friction energy dissipator with piezoelectric ceramics driver, anew type of piezoelectric friction damper was designed. The corresponding dampingforce model was derived, the friction surface friction coefficient was determined. Andunder different preloading, the output performance of calibration test was done underdifferent input voltage. Through linear fitting, and the relationship between the sliding friction damping force and the input voltage is got. Finally, the theoretical output ofdamper is compared with the test output.(2) Design principles and implementation process of fuzzy controller is expoundedfrom the selection of fuzzy variables, the set of domain, fuzzification anddefuzzification, selection of membership function and the design of the control rules,etc. By application of fuzzy logic control toolbox in MATLAB software and thegraphical user interface tools, a two-dimensional fuzzy controller with the double inputand single output is designed. Using the adaptive fuzzy control based on the analyticexpression, fuzzy control rule with four adjustment factors is established, andcorresponding fuzzy controller is designed.(3) Using the designed fuzzy controller, on the basis of the expression ofpiezoelectric friction damper control, and no control and fuzzy control computersimulation models of control system are built based on SIMULINK toolbox inMATLAB software. In the traditional fuzzy control rules and the self-tuning fuzzycontrol rules, simulation analysis of seismic response and control effect for transmissiontower structure is done under El-Centro. The results show that, after structure fuzzyvibration control, peak displacement response and peak speed response of the rest of thelayers get better inhibition except that peak speed slightly enlarges at1st layer. Thedisplacement peak decreases by44.64%, peak speed reduced by37.96%, theeffectiveness of piezoelectric friction damper and adaptive fuzzy controller for structurevibration reduction is verified.(4) The transmission tower structure model is designed. According to the stresscharacteristics of the semi-active bar, taking self-tuning fuzzy control strategy of thestrain response for the input, and simulated earthquake shaking table test of the modelstructure is done. Seismic dynamic response of the El-Centro wave under differentseismic peak acceleration is tested, and the vibration isolation effect of the modelstructure is analyzed under no control, no voltage of passive control and fuzzy control.The results show that fuzzy control effect is up to37.31%, the control effect is obvious. |
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