Influence of Tool Runout on Force Measurement During Internal Void Monitoring for Friction Stir Welding of 6061-T6 Aluminum
| Autor: | Daniel J. Franke, Michael R. Zinn, Shiva Rudraraju, Frank E. Pfefferkorn |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0209 industrial biotechnology
Materials science Mechanical Engineering chemistry.chemical_element 02 engineering and technology Welding 01 natural sciences Industrial and Manufacturing Engineering Computer Science Applications law.invention 010309 optics 020901 industrial engineering & automation chemistry Control and Systems Engineering Aluminium law 0103 physical sciences Void (composites) Friction stir welding Composite material |
| Zdroj: | Journal of Manufacturing Science and Engineering. 143 |
| ISSN: | 1528-8935 1087-1357 |
| DOI: | 10.1115/1.4051009 |
| Popis: | The goal of this research was to examine how altering the amount of friction stir tool eccentricity while controlling the amount of slant in the tool shoulder (drivers of oscillatory process forces) effects the generation of process force transients during sub-surface void interaction. The knowledge gained will help improve the accuracy of force-based void monitoring methods that have the potential to reduce the need for post-weld inspection. Process force transients during sub-surface void formation were examined for multiple tools with varying magnitudes of kinematic runout. The eccentric motion of the tool produced oscillations in the process forces at the tools rotational frequency that became distorted when features (flats) on the tool probe interacted with voided volumes, generating an amplitude in the force signals at three times the tool rotational frequency (for three-flat tools). A larger tool eccentricity generates a larger amplitude in the force signals at the tool’s rotational frequency that holds a larger potential to create a distortion during void interaction. It was determined that once void becomes large enough to produce an interaction that generates an amplitude at the third harmonic larger than 30% of the amplitude at the rotational frequency in a weld with no interaction (amplitude solely at rotational frequency), the trailing edge of the tool shoulder cannot fully consolidate the void, i.e., it will remain in the final weld. Additionally, once the void exceeds a certain size, the amplitudes of the third harmonics saturate at 70% of the amplitude at the rotational frequency during full consolidation. The interaction between the eccentric probe and sub-surface void was isolated by ensuring any geometric imperfection in the shoulder (slant) with respect to the rotational axis was removed. The results suggest that geometric imperfections (eccentricity and slant) with respect to the tool’s rotational axis must be known when developing a void monitoring method from force transients of this nature. |
| Databáze: | OpenAIRE |
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