Dynamic response of cold-formed steel roof trusses subject to blast load

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The popularity of cold-formed steel building components has seen rapid growth in recent years due to its low cost, high strength, and ability to accommodate restrictive design constraints. Despite its extensive use, blast design criteria do not exist for cold-formed steel roof components. Considerable damage sustained by roof members can lead to failure of the structure and detriment to the safety of its inhabitants. Thus, development of adequate design procedures preventing failure of cold-formed steel roof components subject to blast loading is needed. Identifying the behavior and response of cold-formed steel roof structures subject to blast loading is the first step in creating adequate design techniques. The research conducted utilizes experimental and numerical analysis. Experimental research is necessary to better understand the response of cold-formed steel trusses subject to blast loading. This portion of research is comprised of testing three small-scale cold-formed steel roof trusses. The response of trusses subject to loading is evaluated up to ultimate failure. Numerical analysis evaluates 28 roof beam elements subject to a calculated blast load and equivalent roof blast loads. While equivalent loading procedures ease computational effort, the accuracy of such methods remains unknown and must be evaluated. The results of experimental testing provided an understanding of the dynamic response of cold-formed steel trusses subject to blast load. This is a significant contribution as it provides a basis to create design methods for cold-formed steel roof components. The results of numerical analysis indicated that equivalent loading procedures result in significant error in the response of roof components subject to blast load. This finding is pertinent in design because it indicates correction factors should be developed to amend inaccuracies in current procedures. Both of these findings contribute to increasing the safety of building design.