Introducing a Method for Identification of All Dynamic Characteristics Matrices of Shear Buildings Using Output-Only Data

Nowadays, system identification methods have found special place in civil engineering due to extended application in health monitoring and damage detection of structures. Among these, due to limitations caused by stimulation of large scale actual structures, structure engineers are mostly leading toward identification methods based on output-only data. In this study, a method was proposed based on identification of Stochastic Subspace Identification (SSI) method in time domain to identify all structural matrices including mass, damping and stiffness in shear buildings. This method is highly able to identify structural matrices even in working with noise-polluted data. When using SSI with reviewing realization theory, we have never proper information about real degrees of freedom of the system. Hence, system matrices are identifiable in various forms, all of which are true realizations of the system. To explore the main matrices of structural model, the proposed method relies on finding realization of the minimal matrix of the system in the classical form. To evaluate the effectiveness of suggested method, two numerical models of 3 and 5 stories is used. Results of the numerical analysis indicate accuracy of suggested identification method, even in using high noise polluted data.