CCFSS Library (1939 - present)

Alternative Title

Civil Engineering Study 85-3


Allowable Stress Design is the current method used to design cold-formed steel structural members and connections. In this design approach, factors of safety are used to compute the allowable design stresses which are compared to the actual maximum stresses that will occur in the member during the life of the structure. In recent years, the Load and Resistance Factor Design (LRFD) method has been developed for the design of hot-rolled steel shapes and the design of cold-formed steel structural members. This method is based on probabilistic and statistical techniques to account for the many uncertainties involved with the actual design. The LRFD criteria use load factors which are applied to the external load and resistance factors that are applied to the internal resistance capacities of the structure. The allowable unfactored loads based on each design method for different types of structural members are compared and shown in graphical forms. For structural members with one type of loading, the dead-to-live load ratio contributes to the difference between the two allowable loads. For members with a combination of loads, crosssectional geometry, loading conditions, material strength, member length, along with dead-to-live load ratio will affect the difference between the allowable loads computed from allowable stress design and LRFD.


Civil, Architectural and Environmental Engineering


American Iron and Steel Institute

Research Center/Lab(s)

Wei-Wen Yu Center for Cold-Formed Steel Structures

Appears In

Structural Series


Missouri University of Science and Technology

Publication Date

01 Sep 1985

Document Version

Final Version


© 1985 Missouri University of Science and Technology, All rights reserved.


Eighth Progress Report

Document Type

Technical Report

File Type