VERIFICATION OF SHEAR LAG IN LONGITUDINALLY WELDED TENSION MEMBERS

Author

Saurav Shrestha, Southern Illinois University CarbondaleFollow

Date of Award

5-1-2017

Degree Name

Master of Science

Department

Civil Engineering

First Advisor

Hsiao, J.

Abstract

AN ABSTRACT OF THE THESIS OF Saurav Shrestha, for the Masters of Science degree in CIVIL ENGINEERING, presented on November 22, 2016, at Southern Illinois University Carbondale. TITLE: VERIFICATION OF SHEAR LAG IN LONGITUDINALLY WELDED TENSION MEMBERS. MAJOR PROFESSOR: Dr. J. Kent Hsiao, Ph.D., P.E. (CA), S.E. (UT) Tension members are used broadly as bracing members in buildings and truss. When double channels or double tees are welded to a gusset plate, stresses are distributed non-uniformly in connected members since only a part of its cross-section is connected. Shear lag factor describes this phenomenon. The main objective of this study is to verify shear lag factor of tension steel members with welded connections using the finite element computer analysis and the current design Specification for Structural Steel Buildings (AISC 2010). The provision for calculating shear lag factor, U, is given by AISC Specification as 1-x ̅/L for angles, tees, channels and wide flange tension members. Weld size and length of the weld are the main parameters studied here. The current AISC design provision over-estimates the design tensile strength of double channel shapes. While, for WT Shapes it under-estimates one. The increase in weld size and decrease in weld length shows slight change in shear lag factor. Comparison is also made with the equation proposed by Fortney and Thornton (2012). The equation under-estimates the design tensile strength of both sections.