Today, in line with the growth of the construction industry in the world, the quality and speed of construction have been taken into consideration and being developed. Therefore, cold-formed steel structures are welcomed as one of the new products of the construction industry due to their good construction quality, high speed of execution and earthquake resistance. Considering the importance of progressive collapse in structures and the necessity of controlling them, this study aims to evaluate the progressive collapse of cold-formed steel structures. Progressive collapse begins with local failure in one part of the structure and results in major damage which threatens the stability of the structure.
In this study, the progressive collapse with extensive initial failure, the removal of studs and bracing elements, have been investigated. As in many studies to this date in the field progressive collapse of cold-formed steel structure, only the initial failure rate has been limited, In this study, we investigated 15 nonlinear dynamic models for the analysis of 2, 3 and 4 story structures and 10 nonlinear static models for the analysis of 2 story structures. Then, by comparing and analyzing the two methods, the Dynamic Incremental Factor (DIF) have been suggested. Results are expressed and interpreted in terms of maximum and ultimate displacements, the status of the formed plastic hinges, the dynamic response, and how the axial stress is distributed in the structural elements. To analyze and estimate the vulnerability, the structures are modeled in 3 dimensional area in SAP2000 software. According to the results, in all models with 2, 3 or 4 number of stories, the structure remains stable under the limited initial progressive collapse, while the vulnerability of the structure under the extensive progressive collapse increases with increasing in number of stories, and the reliability of the structure decreases with the progressive failure. Dynamic Incremental Factor can