Article
Engineering, Marine
Siyu Wang, Rupeng Zhu, Zhongmin Xiao
Summary: In this study, an improved model is proposed to calculate the mesh stiffness of a helical gear system with cracks, and a dynamic model is established to analyze the vibration response. The results show that cracks can cause a reduction in mesh stiffness and that more severe cracks result in a higher amplitude and more abundant side frequency components in the vibration response.
Article
Engineering, Mechanical
Mahendra Singh Raghav, Shivdayal Patel
Summary: This paper focuses on the effect of spalling on the fatigue life of spur gears. The study reveals that spur gears with spalling fault have a shorter fatigue life compared to those without spalling. It also shows that an increase in backup ratio leads to a significant increase in fatigue life.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Mechanics
Oguzhan Demir
Summary: This paper presents a numerical methodology for predicting crack growth path and life of structures containing cracks, applied to three different case studies on spur gear tooth. Three-dimensional non-planar fatigue crack propagation analyses are conducted using FRAC3D, showing close agreement with available data from the literature in terms of crack growth trajectories. The methodology and criteria introduced can be utilized for three-dimensional crack growth analysis with less user intervention, time, and effort.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Green & Sustainable Science & Technology
Weifei Hu, Weiyi Chen, Xiaobo Wang, Zhiyu Jiang, Yeqing Wang, Amrit Shankar Verma, Julie J. E. Teuwen
Summary: This paper develops an improved computational framework for analyzing fatigue damage in wind turbine blade coating induced by rain erosion, considering different raindrop characteristics and addressing the computational time issue. The results show that the framework can be used to estimate the fatigue life of blade coating due to rain erosion.
Article
Energy & Fuels
Idris Issaadi, Kamel Eddine Hemsas, Abdenour Soualhi
Summary: This paper proposes a method for detecting faults in a wind turbine gearbox equipped with a doubly fed induction generator (DFIG) based on the analysis of generator stator current signals. A localized parameter model was established to simulate the vibratory response of the gear system under healthy and faulty conditions. The results include a detailed analysis of the mechanical and electrical parts of the gearbox, and the FFT analysis was employed to detect gear defects in the stator current signal.
Article
Engineering, Marine
Ming He, Ming Pang, Nian-Zhong Chen
Summary: This paper proposes an engineering critical assessment (ECA) framework for the monopile foundation of offshore wind turbines subjected to pitting. In this framework, a finite element (FE) analysis is conducted based on a 3D model of pitting, and the extended finite element method (XFEM) is used to predict the propagation behavior of pitting cracks. The critical size of pitting cracks is then assessed by a failure assessment diagram (FAD) according to the BS7910. The proposed ECA framework is more effective in assessing the effects of pits on crack propagation, avoiding excessive conservatism in fatigue failure assessment for pitting structures.
Article
Engineering, Multidisciplinary
Xuefei Guan
Summary: This study proposes a new method for uncertainty quantification of finite element-based three-dimensional crack propagation analysis under material uncertainty via extremely few model runs. The method employs the Hankel matrix of moments associated with uncertainty variables to determine the optimal nodes and weights in the variable space for Gauss quadrature. A two-step time integration scheme is employed to further reduce the number of propagation steps within an individual finite element model run. The accuracy of the proposed method is validated using a practical case and it is shown to be effective for capturing the mean and variance of the crack front under material uncertainty.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Mechanical
B. Salehnasab, J. Marzbanrad, E. Poursaeidi
Summary: This study investigated the thermal fatigue life of a detected crack on the edge of the pinhole of a gas turbine engine's hot gas path seal using finite element analysis and nondestructive testing methods. The predicted results were in good agreement with the actual situation.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Materials Science, Multidisciplinary
Jose Alfredo Rodrigez Ramirez, Christian Marisol Clemente Mirafuentes, Manuela Alejandra Zalapa Garibay, Juan Garcia C. Castrejon, Luis Gonzalo Guillen Anaya
Summary: The corrosion fatigue behavior of AISI 410 martensitic stainless steel used in steam turbine blade fabrication was studied using the EN technique under mechanical fatigue conditions. Pitting corrosion occurred in a simulated environment, generating sites for crack initiation and propagation. The presence of localized plastic deformation and the breakdown of the passive layer led to a significant increase in crack propagation velocity and reduced material lifespan.
Article
Materials Science, Multidisciplinary
Hua-Dong Zheng, Bo Zhang, Sheng-Bin Wang, Guan-Zheng Zhou
Summary: The study found that three-bladed and four-bladed VAWTs consistently outperformed two-bladed VAWTs in terms of fatigue life. Increasing the number of blades from two to three was more effective in improving the tower base fatigue life at lower wind speeds, while increasing it from three to four was more effective at higher wind speeds.
Article
Energy & Fuels
Yazid Aafif, Anis Chelbi, Lahcen Mifdal, Sofiene Dellagi, Ilias Majdouline
Summary: This paper investigates two maintenance strategies for wind turbine gearboxes, one based on temperature monitoring and the other based on imperfect preventive maintenance. Mathematical models are developed for optimizing the renewal period and the number of preventive maintenance actions. The economic feasibility of the two strategies is compared.
Article
Engineering, Mechanical
Oguz Dogan, Celalettin Yuce, Fatih Karpat
Summary: Gears play a crucial role in power transmission systems, but are susceptible to high loads and impact forces, leading to surface cracks. By studying different rim thicknesses and pressure angles, the effects on fatigue crack propagation life and root stress were explored, resulting in a significant decrease in maximum stress values and a substantial increase in fatigue propagation life.
ENGINEERING FAILURE ANALYSIS
(2021)
Correction
Engineering, Mechanical
Heli Liu, Huaiju Liu, Caichao Zhu, Zhangdong Sun, Houyi Bai
Summary: The article investigates the impact of surface roughness on contact fatigue of a wind turbine gear pair and corrects the error that occurred during the initial online publication. The article is now an open access publication, following the terms of the Creative Commons Attribution 4.0 International License.
Article
Engineering, Mechanical
Xu Zhang, Jiaxin Zhong, Wei Li, Mateusz Bocian
Summary: This paper investigates the relationship between high-speed gear wear and nonlinear dynamics in a wind turbine gearbox, taking into account tooth contact temperature. The study shows that tooth contact temperature affects the dynamics of the system and increases the extent of gear wear. This research provides a basis for the diagnosis and detection of gear transmission system failures.
MECHANISM AND MACHINE THEORY
(2022)
Article
Engineering, Mechanical
Ran Liu, Dexin Sun, Junling Hou, Fengjun Liu, Qun Li
Summary: This study investigates the fatigue behavior of gears with oxide inclusions under real operating conditions, showing that factors such as inclusion size, position, and residual stress have significant effects on gear fatigue life. The research provides guidance for the engineering design and life safety evaluation of wind turbine gears.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Joao Paulo Dias, Stephen Ekwaro-Osire, Americo Cunha Jr, Shweta Dabetwar, Abraham Nispel, Fisseha M. Alemayehu, Haileyesus B. Endeshaw
INTERNATIONAL JOURNAL OF FATIGUE
(2019)
Article
Engineering, Mechanical
Diogo Stuani Alves, Gregory Bregion Daniel, Helio Fiori de Castro, Tiago Henrique Machado, Katia Lucchesi Cavalca, Ozhan Gecgel, Joao Paulo Dias, Stephen Ekwaro-Osire
MECHANISM AND MACHINE THEORY
(2020)
Article
Chemistry, Multidisciplinary
Samuel Denard, Atila Ertas, Susan Mengel, Stephen Ekwaro-Osire
APPLIED SCIENCES-BASEL
(2020)
Article
Chemistry, Multidisciplinary
Samuel Denard, Atila Ertas, Susan Mengel, Stephen Ekwaro-Osire
APPLIED SCIENCES-BASEL
(2020)
Article
Engineering, Multidisciplinary
Oguz Dogan, Fatih Karpat, Osman Kopmaz, Stephen Ekwaro-Osire
SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES
(2020)
Article
Engineering, Multidisciplinary
Abraham Nispel, Stephen Ekwaro-Osire, Joao Paulo Dias, Americo Cunha
Summary: This study presents a systematic approach to predict the structural reliability of offshore wind turbines under fatigue loading conditions, taking into consideration both deterministic and uncertain input parameters. The results show that wind speed has a high sensitivity on structural reliability, and parameters usually considered as deterministic values also have an impact on structural reliability.
ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART B-MECHANICAL ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Shweta Dabetwar, Stephen Ekwaro-Osire, Joao Paulo Dias
Summary: This paper investigates the capability of artificial intelligence techniques, specifically deep neural networks and Lamb wave measurements, in fault diagnostics of composite materials. The research explores the improvement of diagnostics through data fusion and augmentation.
JOURNAL OF NONDESTRUCTIVE EVALUATION, DIAGNOSTICS AND PROGNOSTICS OF ENGINEERING SYSTEMS
(2022)
Article
Engineering, Multidisciplinary
Shweta Dabetwar, Stephen Ekwaro-Osire, Joao Paulo Dias, Guilherme R. Hubner, Claiton M. M. Franchi, Humberto Pinheiro
Summary: Wind turbines suffer from mass imbalance due to various factors, and effective methods to detect faults at an early stage have not yet been developed. This study explores the use of data augmentation and fusion techniques with deep learning algorithms to enhance the diagnostics of wind turbine mass imbalance. Convolutional neural network techniques were employed to classify imbalance levels using the estimated rotor speed as an input variable. The results showed improvement in the classification and diagnostics of wind turbines.
ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART B-MECHANICAL ENGINEERING
(2023)
Article
Acoustics
Ozhan Gecgel, Stephen Ekwaro-Osire, Utku Gulbulak, Tobias Souza Morais
Summary: Fault diagnosis is crucial for improving operational safety and reducing costs in planetary gearboxes. This study proposes a deep convolutional neural network (DCNN) with data fusion to diagnose gear crack faults using simulated data. The results show that the feature-level data fusion method is robust and accurate in diagnosing crack faults, even in the presence of high levels of noise.
JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME
(2022)
Article
Construction & Building Technology
Enyew Asres, Tewodros Ghebrab, Stephen Ekwaro-Osire
Summary: The conventional methodologies for flexible pavement design are inadequate in addressing sustainability challenges, leading to premature failure of pavements. This study developed a framework for sustainable flexible pavement design, considering resilience, environmental sustainability, and economic sustainability. The framework allows highway agencies to quantify the lifetime sustainability performance of flexible pavements and select the optimum design option, enhancing durability and minimizing costs, disturbances, and environmental impact.
Article
Engineering, Mechanical
Ozhan Gecgel, Joao Paulo Dias, Stephen Ekwaro-Osire, Diogo Stuani Alves, Tiago Henrique Machado, Gregory Bregion Daniel, Helio Fiori de Castro, Katia Lucchesi Cavalca
Summary: A framework using a deep learning algorithm to classify wear faults in hydrodynamic journal bearings was proposed, showing promising results for early diagnosis of wear faults in rotating machinery.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Multidisciplinary
Shweta Dabetwar, Stephen Ekwaro-Osire, Joao Paulo Dias
Summary: This research aims to explore how to improve fatigue damage classification performance of composite materials by combining signal processing techniques with machine learning algorithms. Experimental results show that signal processing can reduce the required number of features for ML training and improve the performance of ML; while randomness in the dataset can be captured by utilizing two specimens from the same material.
ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART B-MECHANICAL ENGINEERING
(2021)
Article
Education & Educational Research
Pratap Chillakanti, Stephen Ekwaro-Osire, Atila Ertas
Summary: Transdisciplinary research involves collaboration among academic, community, government stakeholders to solve complex problems, requiring efficient technology platforms and evaluation tools. This paper aims to improve technology platform evaluation based on TR characteristics, resulting in the development of a core activities and skills chart and a tool for evaluating technology platforms for TR use.
EDUCATION SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Jemal Jibril Muhammed, Priyantha W. Jayawickrama, Stephen Ekwaro-Osire
Proceedings Paper
Computer Science, Theory & Methods
Samuel Denard, Susan Mengel, Atila Ertas, Stephen Ekwaro-Osire
2019 IEEE SECURE DEVELOPMENT (SECDEV 2019)
(2019)