Date of Thesis


Thesis Type

Honors Thesis

Degree Type

Bachelor of Science in Civil Engineering

First Advisor

Ronald Ziemian


In structural and mechanical engineering, welding is known to produce a heat affected zone (HAZ), which is also defined in some specifications as a weld-affected zone. The Aluminum Association¿s (AA) Specification for Aluminum Structures conservatively requires that the reduced material yield strength Fy of the weld-affected zone must be assumed to be the yield strength for the entire adjoined member, and this significant reduction has come under recent scrutiny by members of the AA Specification committee. This thesis presents a computational study on the influence of weld-affected zone on the compressive and flexural strength of aluminum members and the relationship between the longitudinal locations of the weld-affected zone and the buckling strength of beams and columns. This project incorporates the use of two finite element analysis programs: frame analysis software MASTAN2 (2012) and FE++2012. The results of the analysis agree with the prediction that applying reduced material yield strength Fy for the entire adjoined member is conservative. Analyses of a series of beams and columns of varying length and locations of the weld-affected zone indicate that welding location is a key parameter in determining the compressive and flexural strength. Varying moment gradients applied at the beam models illustrated the different levels of influence of locations of the weld-affected zone in different moment scenarios. By comparing the strength curves of both columns and beams developed by the software, and the specifications of AISC and AA, recommendations for the yield strength of welded aluminum members and its relationship with welding locations are presented.