The Research On Sensor Arrangement Method About Structural Seismic Response Observatory Array

With the acceleration of urbanization and the improvement of civil engineering structure design technology,a large number of complex high-rise building structures are planned and constructed.Due to the lack of actual seismic damage experience,these super high-rise complex structures often do not have mature analysis theory and design during design Standards,existing seismic practice and research cannot solve some of the difficulties faced in the design and construction of super high-rise buildings.Long-term real-time vibration observation is the main means of structural health monitoring,damage assessment,and earthquake warning.It can also be used for earthquake resistance.Valuable strong earthquake records have been accumulated through improvement of specifications and earthquake emergency warning.Judging from the current examples of structural seismic response observatory array deployment and code guidance documents at home and abroad,there are no quantitative methods to guide the selection of the location of the structural seismic response observatory array and the determination of the number of sensors.Usually,structural modal information is analyzed The vibration shape is obtained afterwards.According to the vibration shape,the measuring point is arranged at a position where the vibration shape response is relatively large.Since there is no specific quantitative index,the layout result is greatly affected by the engineer's subjective understanding and experience.This paper studies the application of optimized sensor placement methods in structural arrays and does the following:(1)Introduce the basic principles and existing problems of the effective independent method and the gradual accumulation modal confidence method in sensor optimization deployment,and verify the effect of different initial degrees of freedom on the optimization results of the gradual accumulation method;The MAC overall method has been verified on two types of structures;the research idea of using the average value of the non-diagonal elements of the modal confidence matrix formed at the selected position as the optimization index of the MAC method is proposed.(2)Use the finite element software ETABS to establish two structural models.After extracting the modal parameters of the structure,three methods are used to analyze the optimal layout of the sensor,the conclusion as below:The optimal layout of the sensor in the analysis of the measurement points of the structural array It is necessary to apply,it can give quantitative indicators of different schemes to avoid subjectivity and experience.When the MAC method is gradually accumulated,there is no overall consideration of the combined effect of sensor configuration.The choice of initial degrees of freedom will affect the reduction and convergence of modal similarity indicators.The choice of different initial degrees of freedom has a great influence on the entire optimization sequence.The improved MAC method—the overall method has a better optimization effect than the MAC gradual accumulation method.As the number of measurement points increases,the MAC matrix off-diagonal element declines faster,ensuring that the layout scheme is globally optimal.(3)After the layout plan is obtained,two methods are used to measure the advantages and disadvantages of the sensor layout plan: a)whether the selection of the measurement point position can more accurately identify the structural modal parameters;b)whether the selection of the measurement point position can be obtained Whether the larger record is placed in a position where the structure is easily damaged.The following conclusions are drawn: The modal parameter identification effect of the structural seismic response of the MAC integral method is slightly better than that of the EI method;selecting the observation floor according to the MAC integral method makes it easier to obtain the maximum response and damage information of the structure.According to the change curve of the modal similarity index of the MAC method and the effect of modal parameter identification,it can be known that a small number of measurement points cannot observe many vibration modes.If the construction cost determines the number of measuring points,the number of target vibration modes adopted by the MAC overall method should be less than or equal to the number of measuring points.When the EI method is adopted for layer shear structure system,it is only suitable for n target modes and find n observation points.