The American Society of Civil Engineers’ Journal of Structural Engineering has published a new technical paper, “Blast Testing of a Cold-Formed Steel-Framed Building with a Roof Truss System: II. Component-Level Response.” The technical paper is available to download from the ASCE Library.
This paper presents the measured responses of components — blast wall, shear walls, deep beam and bottom chord bracing and a roof truss — of an instrumented, full-scale, cold-formed steel (CFS) framed building subjected to open-arena blast testing. The blast testing provided a rich data set to inform future research, analysis and design of these building components for structures that may be subjected to blast loads.
Funding for personnel, instrumentation and travel for the research presented in this paper was provided by the Charlotte Research Institute and supplemented by the Department of Civil and Environmental Engineering at UNC Charlotte. Materials for the test building were provided by The Steel Network, a Steel Framing Industry Association (SFIA) member.
Blast Walls Examined Using Special Instruments
The behavior of the blast wall was examined through instrumentation of the central stud with linear variable differential transformers, shock accelerometers and strain gauges. Additionally, load cells — installed at several anchors connecting the bottom track of the blast wall to the foundation — recorded hold-down forces along the wall developed during the test.
In-plane displacement vectors and time histories for points on one of the shear walls were obtained from high-speed video. A load cell positioned at an anchor at the bottom track of the shear wall was used to investigate hold-down forces at the shear wall. Forces in the bottom chord bracing of the roof diaphragm were studied through strain measurements.
Lastly, the behavior of the roof truss was studied using measurements obtained from an array of special sensors known as LVDTs, shock accelerometers and strain gauges mounted on the central truss.
CFS Stud Performance Exceeds Current Standards
The results and single-degree-of-freedom analyses provide greater insight into component-level responses and interactions between building components and subcomponents. They also highlight component and connection behaviors that have not been previously documented in the published literature for CFS-framed buildings subjected to blast loads.
The performance of the building components and supporting SDOF analyses demonstrate significant energy absorbing capacity of conventionally constructed CFS stud walls that exceed established performance criteria in current design standards. The results also offer support future development of performance criteria for CFS shear walls and roof trusses, which currently do not exist.
Download from the technical paper from the ASCE Library.
Additional Resources
- ASCE’s Structural Engineering Institute Releases CFS Connection Guide
- SDI Transfers 12 S900 Test Standards to the SFIA Standards Committee
- Construction Begins on 10-Story CFS-NHERI Building, Seismic and Fire Testing to Follow