Dynamic Stability And Criterion Research Of Piezoelectric Intelligent Structure

Along with the development of society and economy, the Long-span spacestructure has been extensively applied in people’s social life and industrial production.But the stems in the Long-span space structure are usually slender, the frequencydistribution of the faulty sensitive structure is also more intensive, and the vibrationmodel number is more. Under the action of strong winds, rain, snow, earthquakes andother complex dynamic loads, the structure is very vulnerable of occurring dynamicinstability and failure damage that bring about heavy loss to people. In recent years, therapid development of intelligent control technology provides a new way to ensurenonoccurrence of such structure dynamic instability. At present the dynamic stabilitycontrol of long-span space structure by using intelligent control technology is still at thestart level, therefore, the in-depth research of dynamic stability of the intelligentstructure has important theoretical significance and practical values.The purpose of this paper is to control the long-span space structure dynamicstability, with designing a piezoelectric sleeve-style and two-way pull-pressureforce-style actuator using the positive and converse piezoelectric effect of thepiezoelectric intelligent materials. And the actuator mechanics test and dynamicstability analysis were researched by using the Piezoelectric Primary Stems as theresearch object. And its main research works are as follow:(1) The relationship between the driving voltage and the driving force wasanalyzed according to the eight piezoelectric sleeve-style and two-way pull-pressureforce-style actuators designed by the research group; The biggest ideal driving forcewas got by the biggest driving voltage that according to the number of the piezoelectricpile pieces; And the driving force performance experimental was investigated. The analysis results showe that the driving voltage and driving force are in a linearrelationship; But there has a certain gap between the test maximum driving force andthe ideal maximum driving force, which illustrates that there is some energy loss whenthe voltage is applied by the reason such as production process etc.(2) The calculation model of analyzing dynamic instability region for thepiezoelectric primary bar was established; the March Equation was deduced under theaction of harmonic loads, with two situations that consideing the electromechanicalcoupling with considering damping and consideing the electromechanical coupling anddamping; the first and the second instability region were solved in such instance; theimplication relation between the relative length of the piezoelectric pile and thedynamic instability region was got. With conducting the numerical Analysis by usingthe MATLAB software, it was verified that the piezoelectric primary stem can play therole of the active control in the structure; there is a conclusion that it can be botheconomic and practical and can rise to the ideal control effect when the piezoelectricpile length is less than or equal to half of the total length in the engineering application.(3) Some common structure dynamic stability criterias at this stage in practicalengineering were summarized, and the practical scopes, the advantages anddisadvantages of the various standards were respectively introduced; the relationship ofthe energy structure changes, structural stiffness matrix’ positive definiteness andstructure dynamic stability was deduce; the structural dynamical stability criteria basedon the energy change was defined, which is applicable to elastic structure; and thevalidity and feasibility of the criteria of the structure’ dynamic stability were verified byusing the ANSYS and MATLAB software, which laid a theoretical foundation fordynamic stability control of the piezoelectric smart structure.