Research Spotlight: Experimental Study on System Reliability of Cold-Formed Steel Roof Trusses
2017 Annual Stability Conference Presentation
Session SS1A – Stability of Thin-Walled Components and Assemblages
Tuesday, March 21, 2017
Experimental Study on System Reliability of Cold-Formed Steel Roof Trusses
This paper presents a research project aimed at advancing the treatment of cold-formed steel (CFS) structural reliability in roof trusses. Structural design today relies almost exclusively on component-level design, so structural safety is assured by limiting the probability of failure of individual components. Reliability of the entire system is typically not assessed, so in a worst-case scenario the system reliability may be less than the component reliability, or in a best-case scenario the system reliability may be much greater than the component reliability. This research assesses a series of full-scale static tests on single cold-formed steel roof trusses with a unique experimental setup. The test specimens were carefully monitored to address multiple failure modes: buckling of the top chord, buckling of the truss webs, and any connection failures. This paper includes the experimental results, the computed system reliability of the trusses as well as their relationship between the components reliability.
Adam M. Johnson and Cheng Yu, University of North Texas, Denton, TX; Brooks Smith and Cristopher D. Moen, NBM Technologies, Inc., Baltimore, MD