Dynamic response prediction of steel frame structure considering semi rigid connection

Abstract

The actual behavior of beam to column connections in steel frames is seldom fully rigid or fully pinned. The actual behavior of the connections is usually semi-rigid. Neglecting the real behavior of the connection in the analysis may lead to unrealistic predictions of the response and reliability of steel frames. Furthermore, the static analysis is normally used in steel frame structure. One of the important issues in the study of steel frames is to find a suitable formulation for semi-rigid connections. The main objective of this investigation was to propose a modeling strategy to represent the dynamical behavior of semi-rigid joints under dynamic actions. This paper presents a semi rigid steel frame linear dynamic analysis by stiffness matrix method and Comparing the modeling results of steel frame with SAP 2000 software. Generally, three types of connection considered with two different densities of frame material and use MATLAB for all calculation. In conclusion, the importance’s of modeling is to determine structural response when coefficient reduced and consequently is effect on lateral rigidity of structure and dynamic characteristics such as vibration periods and frequencies. It is found that, as the spring coefficients factor get bigger amount the behavior of the connection become closer to rigid connection. In dynamic analysis, for each spring coefficient, vibration frequencies of the first mode lower than other mode and exactly in the first mode on excitation frequency, failure is occur in structure. SAP 2000 shows the verification process, in order to determine whether the result obtained from numerical modeling is accurate and reliable