Session Start Date

10-15-1998

Abstract

Self drilling screws are often used for attaching roof and wall panels to structural framing and are subjected to tensile loads caused by negative wind pressures. Pullover failure is often associated with this loading condition, which occurs when It fastener pulls through a metal panel but remains attached to the structural framework underneath. The American lron and Steel Institute (AISI) has developed several standard tests for pullover and has included a design criterion for pullover in their specification. However, previous research at the University of Florida has found one particular test and the AISI Specification Section E4.4.2 to be un-conservative. This discovery inspired researchers to further investigate pullover. In 1993, a proposal was issued to AISI requesting further study of pullover and its effects by testing a wider range of variables. The proposal was approved and research began in May 1994. In order to determine the reduction factor for the standard test, simulated building tests were performed in addition to the standard tests. While initially using the simulated testing apparatus, many difficulties were encountered and adjustments were made to improve the simulated data. From these adjustments a new and improved apparatus for simulated testing (vacuum box testing) was developed. Rather than testing single components alone, this new series included system testing, which modeled the actual conditions more realistically. For these reasons, the system building tests proved most valuable when determining reduction factors for the standard test. After performing the system tests and utilizing the principles of large angle displacement theory, the researchers developed pullover theory. The purpose of the research was to provide a better understanding of pullover by initially determining a reduction factor for the standard test specified in the AISI Cold Formed Steel Design Manual. However, the ultimate objective was to develop both theoretical and empirical methods for designing light gage metal systems that resist pullover.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Meeting Name

14th International Specialty Conference on Cold-Formed Steel Structures

Publisher

University of Missouri--Rolla

Publication Date

10-15-1998

Document Version

Final Version

Rights

© 1998 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Oct 15th, 12:00 AM

Understanding Pullover

Self drilling screws are often used for attaching roof and wall panels to structural framing and are subjected to tensile loads caused by negative wind pressures. Pullover failure is often associated with this loading condition, which occurs when It fastener pulls through a metal panel but remains attached to the structural framework underneath. The American lron and Steel Institute (AISI) has developed several standard tests for pullover and has included a design criterion for pullover in their specification. However, previous research at the University of Florida has found one particular test and the AISI Specification Section E4.4.2 to be un-conservative. This discovery inspired researchers to further investigate pullover. In 1993, a proposal was issued to AISI requesting further study of pullover and its effects by testing a wider range of variables. The proposal was approved and research began in May 1994. In order to determine the reduction factor for the standard test, simulated building tests were performed in addition to the standard tests. While initially using the simulated testing apparatus, many difficulties were encountered and adjustments were made to improve the simulated data. From these adjustments a new and improved apparatus for simulated testing (vacuum box testing) was developed. Rather than testing single components alone, this new series included system testing, which modeled the actual conditions more realistically. For these reasons, the system building tests proved most valuable when determining reduction factors for the standard test. After performing the system tests and utilizing the principles of large angle displacement theory, the researchers developed pullover theory. The purpose of the research was to provide a better understanding of pullover by initially determining a reduction factor for the standard test specified in the AISI Cold Formed Steel Design Manual. However, the ultimate objective was to develop both theoretical and empirical methods for designing light gage metal systems that resist pullover.