: In the Industry 4.0 landscape, spur gears serve as crucial components for power transmission in various sectors like automotive, aerospace, and marine. Despite their widespread application, these gears often face failure due to bending and contact stresses induced by fatigue. Designing the involute gear profile presents notable challenges, particularly in addressing tooth root stresses and interference issues, which are essential from both numerical and experimental perspectives. This study aims to tackle these challenges through a comprehensive stress analysis approach. Leveraging SolidWorks for gear modeling and ANSYS Workbench 18.1 for Finite Element Method (FEM) assessment, the research focuses on evaluating bending stresses at critical locations. The investigation aims to identify strategies to minimize stress concentrations, specifically at the gear tooth root.

Abstract • Background: The aerospace industry has been gradually adopting Industry 4.0 technologies, such as the Internet of Things (IoT), big data analytics, and cyber-physical systems, to enhance aircraft maintenance, repair, and overhaul (MRO) operations. These technologies have the potential to improve operational efficiency, reduce costs, and enhance safety in the MRO sector. • Objective: This study aims to analyze the current state of Industry 4.0 integration in aircraft maintenance/MRO operations by examining relevant use cases and conducting a patent landscape analysis. The primary objectives are to identify the key players, emerging trends, and technological hotspots in this field, as well as to understand the challenges and opportunities associated with the integration of Industry 4.0 in aircraft MRO. • Methods: The research methodology involves a comprehensive literature review to identify and analyze use cases of Industry 4.0 technologies in aircraft manufacturing and MRO operations. A systematic approach was adopted to collect and analyze relevant patent data from various patent databases. The search strategy involved the use of specific keywords related to Industry 4.0 technologies and aircraft MRO. The retrieved patent documents were then subjected to rigorous analysis, including bibliometric analysis, technological categorization, and patent landscape mapping. • Results: The patent landscape analysis revealed a steadily increasing trend in patent filings related to Industry 4.0 technologies in aircraft MRO. The major players in this field were identified, and their patent portfolios were analyzed. The analysis of use cases also highlighted the key technological areas, such as 3 D Printing and digital twin technology, are attracting significant attention from aircraft industry stakeholders. • Conclusion: The analysis of patent landscapes in the field of aircraft maintenance, repair, and overhaul (MRO) provides valuable insights into the current state, emerging trends, and future directions within the industry. These insights are crucial for industry stakeholders, researchers, and policymakers to make informed decisions regarding technology adoption, investment strategies, and regulatory frameworks. In conclusion, the examination of patent landscapes serves as a foundational tool for enhancing transparency, standardization, and reproducibility in research, enabling stakeholders to navigate the complex landscape of Industry 4.0 in aircraft MRO effectively.

Abstract: Background: In today's world, the design of a product plays a pivotal role in its sustainability throughout its lifecycle, from production to usage and disposal. With mounting regulatory and competitive pressures on businesses, the decisions made in product design have never been more critical. In this context, nature is an invaluable source of inspiration for creating sustainable products. Objective: This research endeavour aims to investigate the trends, progress, and disparities in research related to nature-inspired product designs using bibliometric analysis. Methods: The study leveraged the Scopus database to achieve this objective, referencing data collected up to August 21, 2023. A total of 251 English-language records were deemed suitable for bibliometric analysis. The collected data was meticulously analyzed utilizing tools such as Microsoft Excel, Vos Viewer, Scopus Analytics, and Orange software, focusing on key parameters, including publication year, country of origin, subject area, citation metrics, and keywords. Result: The analysis pinpointed that 2022 witnessed the highest research volume on nature-inspired product design. A significant majority of this research was published within the engineering subject area. India emerged as the leading producer of academic documents in this field, contributing 54 documents, while authors Ruiz R., Pan Q.-K., and Naderi B. were the most frequently cited, amassing a total of 248 citations. Additionally, Iglesias Andrés stood out as the most prolific individual scientist. Regarding organizational support, the National Natural Science Foundation of China (NSFC) played a prominent role in funding research on the utilization of nature's influence in product design and manufacturing. Furthermore, this study identified a convergence axis grouping various keywords, including "optimization," "algorithms," "design," "manufacturing," "inspired," "biomimetics," "nature," "nature-inspired," "material," and "product." These results provided evidence of the multidimensional nature of research in this domain and its potential impact on sustainable product design and manufacturing. Conclusion: By analyzing the volume of publications, citation patterns, and collaboration networks, researchers assessed the influence and relevance of nature-based product design and manufacturing in the scientific community, academia, and society through sustainable manufacturing, additive manufacturing, computer modelling, human-centric design, regenerative design, and circular economy.

To improve the performance of the adhesive layer defect detection planar array capacitor system, an adhesive layer defect detection method based on particle swarm optimization and fuzzy c-means clustering algorithm was proposed. By classifying capacitance data with errors, the experiment distinguished the capacitance values at defect locations from those at defect-free locations. In response to the presence of artifacts in the image reconstruction results, the optimal threshold method was used to post-process the reconstructed images using the mixed regularization method. These experiments confirmed that fuzzy C-means clustering reduced the average absolute value deviation of data by about 6.1%, and the proposed clustering algorithm reduced the average absolute value error of data by about 23.2%. Compared to Tikhonov, the mixed regularization method reduced the relative error of reconstructed images by about 13.1% and increased the correlation coefficient of reconstructed images by about 21.6%. Therefore, this research method had significant effects in reducing data fluctuations and errors, effectively improving the image reconstructing quality and the accuracy of defect detection. This study can effectively improve the accuracy of adhesive layer defect detection, help reduce production costs, and improve production efficiency.

The three-span steel truss arch bridge assembled by cantilever generally ensures the stability of the structure against overturning by adding weight to the side span during construction. The closure of the main arch in the middle span is generally achieved by longitudinally moving the overall arch frame and lifting the edge support points to achieve the overall adjustment of the main arch posture and complete the unstressed closure of the main arch. The side to mid span ratio of a three span steel truss arch bridge is generally greater than 1:3. When the side to mid span ratio is small and conventional weight balancing methods cannot meet the requirements, external prestress is used to anchor the edge support points to improve the anti overturning stability of the main arch. However, it also leads to the problem that the steel truss arch posture cannot be adjusted through pushing or lifting at the support points after anchoring the edge support points. This article uses finite element software to accurately calculate the pre-offsetting and pre-reduction of the main arch. By adjusting the tension of the prestressed cable, the height difference on both sides of the closure is eliminated. Through structural deformation analysis based on the lifting sequence of the members, the distance change of the closure is accurately calculated, and the high-precision closure of the main arch is achieved by utilizing temperature changes. This article verifies the conclusion that steel truss arch bridges with fixed edge supports can also achieve high-precision closure of the main arch.