Rationale Behind and Proper Application of the Ductility Factor for Bracing Connections Subjected to Shear and Transverse Loading

January 28, 2004
Publication: Engineering Journal
Author(s): Christopher Hewitt William A. Thornton

In 1990, AISC and ASCE jointly commissioned a task group to develop a design philosophy for predicting the strength of bracing connections. The design methods in place prior to that time were only applicable to connections made to the webs of columns, as a proper methodology for brace-to-column flange connections had not been agreed upon. The overall goal was to create a complete design philosophy that could be used to accurately predict the strength of bracing connections and ensure ductile structural response.
The task group devised a study of five bracing connection design methods. Among the five design methods evaluated were the Uniform Force Method, developed by Thornton (1991), and a modified version of a design method developed by Richard (1986). The study included a comparison of the predicted response of each model to the actual response found by testing in both isolated, Bjorhovde and Chakrabarti (1985), and complete frame action cases, Gross (1990), for each bracing connection. After extensive study and comparison the committee recommended the use of the Uniform Force Method as the most accurate predictor of the true structural response of bracing connections. 

Read the full article.

Services: Structural Design