Abstract

Finite element models of friction welding can be used to estimate internal conditions of welds which are useful for weld analysis and developing experimental welding procedures. Many modeling techniques are used to accomplish these goals, each with relative strengths and weaknesses. A comparative analysis of friction welding models using different heat generation methods is presented. The three different heat generation methods examined were viscoplastic friction, constant steady-state generation, and experimentally measured power data. The models were compared against each other using three output measurements: temperature, axial force, and upset. The friction model predicted temperatures within 40 degrees C. Temperature accuracy improved at a higher upset rate and higher spindle speed, when weld samples heated up faster. The model was excellent at predicting upset, with accuracy within 1.5%. Maximum force was predicted within 9-18%. The constant heat generation model typically predicted temperatures within 30 degrees C. Upset was estimated within 7%. Maximum force was predicted within 12% at high feed rates, but accuracy dropped to 28% when feed rate was reduced. The motor power model was the most accurate model at estimating temperature, with a typical accuracy within 25 degrees C. Axial upset was predicted within 5%. Maximum force was predicted within 1-8%, with greater accuracy occurring at higher feed rates.

Degree

College and Department

Ira A. Fulton College of Engineering and Technology; Mechanical Engineering

Rights

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