Artic Determination of Dynamic Characteristics the Structure with ARX and ARMAX Estimation Methods

Abstract

In this study, the dynamic behavior of a single-span four-storey steel model structure is tried to determine by using 2 different methods. Connections between beams and columns are produced as rigid and the structure is connected to the shake table by a fixed support. In order to measure the forced vibration values applied to the model structure with the help of the shaking table, the smartphone was placed on the shaking table base and the top of the steel model structure and acceleration records were taken. After the records have been processed, structural algorithm is created using MATLAB autoregressive ARX and autoregressive moving average ARMAX models. Smartphone records from the shake table are defined as inputs and smartphone from the top of the structure are defined as outputs in MATLAB autoregressive ARX and autoregressive moving average ARMAX models. By doing this, structure’s dynamic behavior is to be obtained by MATLAB autoregressive ARX and autoregressive moving average ARMAX models when only vibrating table acceleration record is inputted. Dynamic characteristics obtained by ARX and ARMAX were tried to be confirmed by finite element method using Sap2000 software. In order to determine the dynamic characteristics of the building, the earthquake records of Kobe, Sakarya, Loma-Priate and El-Centro were used as forced vibration. At the end of the study, dynamic properties obtained by numeric models (ARX and ARMAX) using input acceleration record are compared to the dynamic properties obtained by Sap2000 analysis. By doing this it was determined whether dynamic properties can be reliably obtained using autoregressive ARX and autoregressive moving average ARMAX models. Advantages and disadvantages of using this method to define structural behavior are discussed.