جستجوی مقالات مرتبط با کلیدواژه "simplified model" در نشریات گروه "عمران"

Nowadays, extensive nonlinear dynamic analysis is widely used in different fields of research and design of structural and earthquake engineering. It has been applied in performance-based design, resilience-based design, and also other probabilistic fields and optimization. This extensive analysis imposes a high computational cost on the researcher. However, using simplified models is an appropriate approach. The Substitute Frame is a simplified model for steel and RC moment frames, which on the one hand predicts the displacement responses of the frame with very good accuracy and on the other hand, reduces the analysis time by several times. Despite numerous evaluations of the substitute frame model in nonlinear dynamic analyses, incremental dynamic analyses, and fragility analyses, the model's accuracy has not yet been investigated for predicting moment frames' force responses. In performance-based engineering, force-control actions should be designed to prevent the undesirable failure mechanism. Hence, in this study, first, the force response of the columns was predicted using the substitute frame model, and then its accuracy was evaluated comparing to the original frame response. The results of evaluations showed that the substitute frame predicts the columns bending moments, shear forces, and axial forces of the original frame with more than 90% accuracy.

In recent years, dynamic analysis has been considered as an appropriate tool in the earthquake engineering field. On the other hand, the number of analyzes required in the research and design field has grown. So, in some fields of research with a probabilistic approach, resilience or optimization, requires extensive nonlinear dynamic analyses. Performing such a mass analysis has a very high computational cost and requires a lot of analysis time. One of the practical solutions to this problem is the use of simplified models that significantly reduce the total analysis time with appropriate and acceptable accuracy compared to the detailed model. In this research, in order to determine the collapse margin ratio of structures, three 8-,12-, and 20- story buildings have been considered. By performing the incremental dynamic analysis (IDA) on the detailed model and the substitute frame model, their collapse intensities and collapse margin ratio have been calculated. The results show that the substitute frame model determines the collapse margin ratio with an error rate of 3%, and also reduces the analysis time by an average of 2/5%.