Laterally unsupported purlins subjected to uplift

INTRODUCTION A research study, conducted at Cornell University, provided a theoretical method for evaluating the state of stress for both C- and Z- purlins subjected to wind uplift loading. According to the Cornell analytical method, a Z-purlin has more load carrying capability than a similar C-purlin. Although experimental verification was provided, questions were raised, within the Metal Building Industry, regarding the strength of the C-versus the Z-section. The purpose of the work discussed herein was to develop information regarding the behavior of C- and Z-sections having identical cross-section dimensions. A brief description of the test program, along with a comparison between the tested ultimate capacity and computed capacity, is presented

Corrosion of Galvanized Fasteners used in Cold-Formed Steel Framing

The primary objective of this project was to study the effect of corrosion on the structural integrity of galvanized fasteners used in cold-formed steel-framed construction. A number of specific tasks were developed to meet this objective, including a literature search, design and construction of field enclosures, determination of test sites and installation of field enclosures, test specimen design and fabrication, accelerated corrosion testing, structural tensile testing, data analysis and technology transfer

Strength of cold-formed steel beam webs in bending, shear, and a combination of bending and shear

An extensive experimental investigation has been conducted to study the load-carrying capacity of cold-formed steel web elements subjected to bending stress, shear stress, and a combination of bending and shear stresses. Emphasis has been concentrated on the instability and postbuckling strength of beam webs. In the study of beam webs subjected only to bending, the postbuckling strength of web elements and the effect of the compression flange on the moment capacity have been carefully evaluated for beams having stiffened and unstiffened flanges. Based on 84 test results, formulas have been developed to predict the ultimate moment capacity of cold-formed steel beams with due consideration given to the actual bending strength of web elements. These formulas are based on either the full web area or the effective web area. For a study of beam webs subjected primarily to shear, the results of 43 tests have been compared with the theoretical failure stress. It was found that the ultimate shear strength of cold-formed steel beam webs is affected significantly by the loading and support conditions. The structural behavior of cold-formed steel web elements subjected to combined bending and shear was also investigated. Interaction formulas have been developed to calculate the ultimate capacity of web elements with due consideration given to the postbuckling strengths for both bending and shear --Abstract, page iii