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Study on the Fatigue Bending Strength of Cylindrical Components Manufactured by External WAAM
Van-Minh Nguyen1, Pham Son Minh1, Dang Thu Thi Phan1
1Faculty of Mechanical Engineering, HCMC University of Technology and Education, Ho Chi Minh City 71307, Vietnam.
Materials (Basel, Switzerland)
|October 29, 2025
Summary
This study optimized wire arc additive manufacturing (WAAM) parameters to enhance fatigue bending strength in cylindrical components. Key factors like specimen gauge diameter and weld current significantly improved fatigue life, approaching traditional manufacturing performance.
Area of Science:
- Materials Science
- Mechanical Engineering
- Manufacturing Processes
Background:
- Additive manufacturing (AM), specifically wire arc additive manufacturing (WAAM), offers potential for producing complex metal components.
- Understanding and optimizing the fatigue performance of WAAM components is crucial for their widespread industrial adoption.
- Fatigue bending strength is a critical parameter for structural integrity, yet it remains a challenge for AM materials.
Purpose of the Study:
- To investigate and optimize the welding parameters influencing the fatigue bending strength of WAAM-produced cylindrical components.
- To identify the dominant parameters affecting fatigue life and establish optimal settings for maximizing the Mean of Fatigue Cycles (N).
- To compare the fatigue performance of WAAM components with traditional manufacturing methods.
Main Methods:
- A Taguchi L25 orthogonal array design was employed to systematically evaluate five welding parameters: welding current, offset distance, step length, welding speed, and specimen gauge diameter.
- Signal-to-noise (S/N) ratios were used to determine the optimal parameter settings for maximizing fatigue cycles (N).
- Analysis of Variance (ANOVA) and linear regression analysis were performed to identify significant parameters and model the fatigue strength.
Main Results:
- Specimen gauge diameter (17 mm) and weld current (125 A) were identified as the most dominant factors influencing fatigue strength, accounting for approximately 75% of the variance.
- Optimal settings predicted a fatigue life of 350,000-380,000 cycles, representing a 22-33% improvement.
- WAAM components achieved 80-90% of the fatigue performance of traditionally manufactured parts, with a 10-20% gap attributed to microstructural differences.
Conclusions:
- The study successfully optimized WAAM parameters to significantly enhance fatigue bending strength.
- Post-treatments and the application of safety factors (approximately 1.2) are recommended to bridge the performance gap with traditional manufacturing.
- Further research with larger datasets or nonlinear models is suggested to mitigate overfitting issues observed in the linear regression analysis.
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