Research On Inertial Piezoelectric Vibration Exciting System

The vibration exciter and vibration control system is one of the key equipmentsin experiment study of structural dynamics characters， and the research onimproving its efficiency has important actual applied value．In order to meet therequirements of high frequency vibration exciting, simulating the actual forceconditions of the tested structure and avoiding over vibration test in structuralvibration test, this dissertation follows the research philosophy and design methodof the theory analysis as basis, dynamic design theory as guide，combination ofmodel emulation technology， experiment testing as authentication method,researching and developing a set of vibration exciting equipment which includes ofinertial piezoelectric vibration exciter, power amplifier for capacitive load anddigital sine sweeping vibration control system．The following contributions havebeen made：The structure of new piezoelectric vibration exciter based on inertial workingprinciple is presented．A two degrees of freedom dynamic model of electro-mechanical coupling structure in vibration exciter is established，according todynamic design methodology, in combination with the piezoelectric equations andthe theory of structural dynamics．By use of MATLAB/SIMULINK and ANSYSsoftware，lumped parameters dynamic model and discrete finite element model areestablished and be used for model simulating，and the simulation results arecompared to validating．After considering of the influence on the excitation capacityof the main part parameters in vibration exciter，appropriate physical parameters aredetermined at last．And the design theory can also be used as reference for the samekind of structure．Based on the linear amplifier circuit and current extending method，the circuitdesign and implementation pattern of power amplifier based on two-stage amplifierwith voltage and current are proposed．For the feature of piezoelectric as acapacitive load，the main amplifier with two-stage circuit is projected，and simulatedwith the Multisim software． After careful investigations on the generatingmechanism and elimination of self-oscillation，analysis and design on the auxiliary circuits such as the current limited，the overvoltage protection，the overheatprotection and the DC power supply，a bipolar power amplifier with wide frequencyrange，high voltage and high current，is accomplished．The control manner for vibration exciting and controlling system with dualcontrol modes on the exciting force of the exciter and acceleration of the testedstructure is presented．Studies on force amplitude control strategy by the fuzzyadaptive control algorithm based on system identification， and accelerationamplitude limited control，are completed．By using of virtual instrument platform，taking digital sine sweep as an example，the software for vibration controlling isdeveloped． Following the analysis to the work procedure of the softwarearchitecture and man-machine interface，the whole program of digital vibrationcontrol system is accomplished．Test programs and test methods are designed for the manufactured actualsubject including the exciter， the power amplifier and the vibration controlsystem．The experimental results are consistent basically to the expectation， thedesign targets for high frequency vibration exciting and controlling are achievedsuccessfully．So the feasibility of vibration exciting system and the validity of thedesign theory are confirmed．The research contents and achievements have greatsignificances on promoting the experiment capability and the accuracy of thestructural dynamics．...