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Research Article
Comparison of Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) in Optimisation of the Thermal Diffusivity of Mild Steel TIG Welding
Augustine Oghenekevwe Igbinake*
Issue:
Volume 9, Issue 2, June 2025
Pages:
43-49
Received:
17 February 2025
Accepted:
3 March 2025
Published:
28 March 2025
Abstract: This study compares the effectiveness of Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) in optimizing the thermal diffusivity of mild steel Tungsten Inert Gas (TIG) welds. The analysis evaluates the predictive accuracy and optimization efficiency of both techniques, providing insights into their suitability for modeling thermal behavior in welding applications. The set of tools, including power hacksaw cutting and grinding machines, mechanical vice, emery (sand) paper and sander was used to prepare the mild steel coupons for welding. The produced coupons were evaluated for their Thermal Diffusivity. The two expert systems used to determine the effect of the interaction of welding current, welding voltage and gas flowrate on the Thermal Diffusivity were the Response Surface Methodology and Artificial Neural Network. The models were validated using the model summary values between the experimental results compared to RSM (R2 = 94.49%) and ANN (R2 = 97.83%) values. This shows that ANN is a better predictor as compared to RSM.
Abstract: This study compares the effectiveness of Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) in optimizing the thermal diffusivity of mild steel Tungsten Inert Gas (TIG) welds. The analysis evaluates the predictive accuracy and optimization efficiency of both techniques, providing insights into their suitability for modeling the...
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Research Article
Vibration Testing of 3D-Printed Turbine Blades: Precautions and the Application of Scale Factors in Design
Issue:
Volume 9, Issue 2, June 2025
Pages:
50-56
Received:
28 February 2025
Accepted:
12 March 2025
Published:
31 March 2025
Abstract: Testing of components and systems is a specialized discipline that often involves complex instrumentation schemes, dedicated test rigs, and meticulous interpretation of results after assessing measurement accuracies. Turbine blades, especially those made of super alloys like Nimonic, have been subjected to vibration testing for over seven decades for research, design validation, and quality control. In recent years, advancements in 3D printing have transformed manufacturing processes, evolving from plastic powders and filaments to metal powders, enabling the production of functional components for industrial applications. Small turbine blades have been successfully manufactured using additive manufacturing (AM) techniques, particularly for wind tunnel and vibration testing, to support design and performance evaluation. This paper presents the experimental investigations conducted on a 3D-printed gas turbine stage blade subjected to vibration testing. The study outlines the test methodologies, instrumentation, and data acquisition techniques employed to evaluate the dynamic behavior of the printed blade. Additionally, key precautions necessary to ensure reliable testing and accurate result interpretation are discussed. A significant aspect of this work is the correlation between vibration characteristics of 3D-printed blades and actual steel blades used in gas turbines. The paper explores predictive techniques that facilitate the estimation of dynamic parameters in real turbine blades based on results obtained from 3D-printed prototypes. The findings contribute to the growing understanding of how additive manufacturing can aid in early-stage design validation and provide insights into the feasibility of using 3D-printed components for experimental testing in turbomachinery applications.
Abstract: Testing of components and systems is a specialized discipline that often involves complex instrumentation schemes, dedicated test rigs, and meticulous interpretation of results after assessing measurement accuracies. Turbine blades, especially those made of super alloys like Nimonic, have been subjected to vibration testing for over seven decades f...
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Research Article
Estimation of Solidus and Liquidus Temperature of TIG Mild Steel (S275) Using Response Surface Methodology
Augustine Oghenekevwe Igbinake*
Issue:
Volume 9, Issue 2, June 2025
Pages:
57-63
Received:
11 April 2025
Accepted:
22 April 2025
Published:
26 May 2025
DOI:
10.11648/j.ajmme.20250902.13
Downloads:
Views:
Abstract: The solidus and liquidus temperatures are critical parameters in materials science, particularly for alloys, defining the boundaries between solid and liquid phases during melting and solidification. The solidus is the highest temperature at which an alloy is excellent, and the liquidus is the lowest temperature at which an alloy is completely liquid. Understanding these temperatures is crucial for processes like casting, brazing, and materials' behavior under high temperatures. This research aims to estimate the solidus and liquidus temperatures of mild steel (S275) weld metal by applying Response Surface Methodology (RSM) to the Tungsten Inert Gas (TIG) welding process. The input parameters considered in the study include welding current, welding voltage, and gas flow rate, while the output responses are the solidus and liquidus temperatures. The methodology helps identify the optimal combination of these input parameters that yields the most accurate values for the solidus and liquidus temperatures of the mild steel weld metal. The suggested model for solidus temperature has an R2of 0.9984, an Adjusted R2 of 0.9970, and a Predicted R2 of 0.9306. In contrast, Liquidus temperature has an R2 of 0.9997, an Adjusted R2 of 0.9994, and a Predicted R2 of 0.9994, showing a significant model and indicating a desirability value of 91.5%.
Abstract: The solidus and liquidus temperatures are critical parameters in materials science, particularly for alloys, defining the boundaries between solid and liquid phases during melting and solidification. The solidus is the highest temperature at which an alloy is excellent, and the liquidus is the lowest temperature at which an alloy is completely liqu...
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Review Article
Towards a Circular Economy: A Comprehensive Review on the Reuse of Steel Bridge Members with Fatigue Damage in Structural Applications
Girmay Mengesha Azanaw*
Issue:
Volume 9, Issue 2, June 2025
Pages:
64-75
Received:
25 March 2025
Accepted:
30 April 2025
Published:
29 May 2025
DOI:
10.11648/j.ajmme.20250902.14
Downloads:
Views:
Abstract: This comprehensive review explores the potential for reusing steel bridge members with fatigue damage in new structural applications, emphasizing the transition towards a circular economy in the construction industry. Steel bridges, known for their durability, often face fatigue-related degradation due to cyclic loading, leading to their decommissioning. However, with advancements in non-destructive testing (NDT), structural health monitoring (SHM), and repair technologies, these components can be repurposed effectively for secondary uses in both bridge and building structures. This paper examines key methods for assessing fatigue damage, including traditional NDT techniques such as ultrasonic testing, magnetic particle inspection, and newer machine learning-based SHM systems that provide real-time monitoring of fatigue progression. Additionally, innovative repair and strengthening strategies, such as the use of advanced composites and structural retrofitting, are reviewed to restore residual strength and extend the service life of damaged steel members. Design integration for reused steel components is also explored, focusing on safety and performance, and including the application of computational models to validate design changes. The environmental and economic benefits of steel reuse are discussed, highlighting reduced carbon footprints, minimized resource consumption, and cost savings, while contributing to a circular economy framework. The paper provides case studies and real-world applications where reused steel components have been successfully integrated into new infrastructure projects. Lastly, the paper identifies gaps in current policies, standards, and regulations, offering recommendations for accelerating the adoption of circular economy principles in steel construction. This review is crucial for fostering sustainability in structural engineering and paves the way for future research on enhancing the reuse potential of fatigue-damaged steel bridge members.
Abstract: This comprehensive review explores the potential for reusing steel bridge members with fatigue damage in new structural applications, emphasizing the transition towards a circular economy in the construction industry. Steel bridges, known for their durability, often face fatigue-related degradation due to cyclic loading, leading to their decommissi...
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