Article
Engineering, Mechanical
Dao-Hang Li, De-Guang Shang, Hong Chen, Ling-Hua Cong, Jin-Jie Wang, Xue-Peng Zhou, Yi-Ru Zhao, Wei Li, Zheng-Yu Mao
Summary: This paper presents an experimental investigation on the cyclic deformation behavior and fatigue damage mechanism of TC4 titanium alloy under multiaxial thermo-mechanical loading. The results reveal that the combined action of high temperature, tensile stress, and shear stress can activate the fast cracking mode of the material, causing a rapid degradation in its axial mechanical properties and a significant decrease in its failure life. Additionally, non-proportional additional hardening and tensile mean stress contribute to the fatigue and oxidation damages of the material, with the material's damage behavior being temperature and time dependent.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Mechanics
Dao-Hang Li, De-Guang Shang, Zheng-Yu Mao, Hong Chen, Ling-Hua Cong, Zhi-Qiang Tao
Summary: A life prediction method for titanium alloy TC4 under multiaxial thermo-mechanical fatigue loading is proposed, considering temperature and time dependent influence factors. The method includes the use of strain amplitude-life curve, mean stress, and a multiaxial damage parameter to account for fatigue and oxidation damages caused by various factors. Test data under different loading conditions are used to validate the proposed method with satisfactory accuracy.
ENGINEERING FRACTURE MECHANICS
(2023)
Review
Engineering, Mechanical
Jan Papuga, Adam Kal'avsky, Maxim Lutovinov, Ivona Vizkova, Slavomir Parma, Martin Nesladek
Summary: This paper establishes clear rules for evaluating experimental data for validating multiaxial fatigue strength criteria, aiming to identify and eliminate data that could lead to erroneous conclusions, hide trends, or introduce bias. Various reasons for rejecting specific data sets are provided and two appendices list accepted and rejected data sources.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Michal Bartosak, Jakub Horvath, Miroslav Spaniel
Summary: The study found that non-proportional loading increases fatigue damage and decreases observed lifetime in low-cycle fatigue tests. A TMF damage model was proposed to account for the effects of multiaxial loading and temperature variations. The model, based on a critical plane approach, incorporates fatigue, oxidation, and creep forms of damage and is validated against a large experimental database.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Aerospace
Jingmeng Weng, Tong Meng, Weidong Wen, Shaodong Weng
Summary: This study focuses on the fatigue lives of composite laminates under different tension-torsion biaxial fatigue loading paths. By establishing a macro-meso model, the fatigue life of composite laminates can be predicted with numerical results showing good agreements with experimental data.
CHINESE JOURNAL OF AERONAUTICS
(2021)
Article
Engineering, Mechanical
Ensheng Feng, Xiaogang Wang, Chao Jiang
Summary: This paper compares the critical plane approach (CPA) and the dissipated energy approach (DEA) for multiaxial fatigue evaluation. The study finds that the developed DEA model performs better than classic CPA models in terms of prediction accuracy and versatility to different loading paths. An investigation into crack mechanisms reveals that the majority of multiaxial fatigue life is spent on the formation of micro-cracks, which exhibit distinct characteristics under different loading paths. The DEA model is able to better consider this effect compared to the adopted CPA models.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Andreas Hottin, Moussa Nait Abdelaziz, Abderrahim Talha, P. Charrier
Summary: The continuum damage mechanics approach allows quantifying material degradation using a damage variable D. A new equivalent stress is developed to analyze multiaxial fatigue in rubbers, which is validated through fatigue experiments on Natural Rubber and comparison with data on Styrene Butadiene Rubber. The nice agreement between experimental data and model estimates in terms of fatigue life makes this approach a robust tool for designing rubber parts.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Rita Dantas, Jose Correia, Grzegorz Lesiuk, Dariusz Rozumek, Shun-Peng Zhu, Abilio de Jesus, Luca Susmel, Filippo Berto
Summary: Multiaxial stresses are common in engineering structures, leading to multiaxial fatigue issues with different opinions and models for its description. Experimental research revealed that the multiscale approach by Dang Van and the Susmel model showed high accuracy and correlation in describing the fatigue behavior of S355 structural steel.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Geological
Savani Vidana Pathiranagei, Ivan Gratchev
Summary: The severity of underground rock dynamic disasters is increasing due to the deepening of human operations underground. Understanding the thermo-mechanical behavior of rocks is important for the long-term safety and maintenance of underground tunnels and mining. This study proposed a statistical coupled thermo-mechanical constitutive model for sandstone under high temperature and pressure conditions, and validated the model using triaxial test results. The model showed good agreement with the experimental results up to 600 degrees C.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Engineering, Mechanical
G. Morettini, C. Braccesi, F. Cianetti, S. M. J. Razavi
Summary: Multiaxial random experimental fatigue tests were conducted with a new specimen geometry, using a circular specimen and a frequency resonance system. The proposed modal approach was validated both numerically and experimentally. The goal of the study was to define the Wodhler curve of the component using forecast data from the BVM method, with fractography analyses of the tested specimens to complete the investigation.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Nuclear Science & Technology
Wenhai Guan, Hyoseong Gwon, Takanori Hirose, Hisashi Tanigawa, Yoshinori Kawamura, Motoki Nakajima, Takashi Nozawa
Summary: This study conducted creep-fatigue tests on F82H at 823 K, comparing tension holding with compression holding. It was found that CF damages were within the damage envelope of Grade 91 in ASME NH, indicating the potential resistance of the cylindrical WCCB TBM design under ITER thermo-mechanical load conditions.
FUSION ENGINEERING AND DESIGN
(2021)
Article
Chemistry, Physical
Meng Wang, Jianchao Pang, Xinfeng Liu, Jianqiu Wang, Yongquan Liu, Shouxin Li, Zhefeng Zhang
Summary: The microstructures of eutectic Al-Si alloys have a significant influence on the fatigue life and damage mechanisms under thermo-mechanical fatigue (TMF) loading. Ultrasonic melt treatment (UT) can effectively reduce the grain size and primary Si, resulting in an increased fatigue life. There are two different crack initiation mechanisms under TMF, which are fracture of Si particles and debonding of primary Si. The UT alloy exhibits a longer TMF life due to the refinement of microstructures, which plays an important role in improving fatigue resistance and life.
Review
Materials Science, Multidisciplinary
Pietro Foti, Nima Razavi, Ali Fatemi, Filippo Berto
Summary: Additive manufacturing techniques offer the possibility of highly customized components with manipulated material composition and geometrical properties. However, the application of additively manufactured parts on an industrial scale is limited due to the high variability in mechanical properties and the challenge of assessing their structural integrity and fatigue life. This review provides insights into multiaxial fatigue in additively manufactured metallic components and presents life prediction methodologies for fatigue damage assessment under multiaxial fatigue loading.
PROGRESS IN MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
G. Yang, X. Y. Long, Y. Zhang, F. C. Zhang, G. J. Du, Z. L. Liu, Y. G. Li
Summary: The influence of monotonic mechanical properties on the low-cycle fatigue lifetime of carbide-free bainitic steel is investigated. It is found that an increase in dislocation density and a decrease in bainitic ferrite lath size lead to an increase in tensile strength, while a decrease in retained austenite volume fraction leads to a decrease in elongation. The mathematical analysis of fatigue lifetime in terms of tensile strength, elongation, and static toughness can effectively predict the variation of the LCF lifetime for different grades of bainitic steels.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Zhi-Qiang Tao, Guian Qian, Xiang Li, Jingyu Sun, Zi-Ling Zhang, Dao-Hang Li
Summary: This article proposes an innovative approach for determining the critical plane with weight-averaged largest fatigue damage, considering the failure modes of materials. Depending on the shear cracking behavior or tensile failure behavior of the material, an appropriate critical plane model is selected, and a multiaxial fatigue lifetime estimation methodology is established. Validation results using six materials demonstrate that the proposed methodology accurately estimates the orientation angles of failure planes and provides satisfactory fatigue lifetime estimations for both shear and tensile failure mode materials. Furthermore, the critical plane framework can be extended to stress-based fatigue criteria, and prediction results are in good agreement with experimental data for two additional materials.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Mathematics
Branislav Panic, Jernej Klemenc, Marko Nagode
Article
Mathematics
Branislav Panic, Jernej Klemenc, Marko Nagode
Article
Engineering, Mechanical
Marko Nagode, Jernej Klemenc
Summary: This study compared different probability density mixtures and estimation algorithms for modeling rainflow matrices. Procedures were identified to enable more thorough consideration of clusters with less probable load cycles.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Materials Science, Multidisciplinary
Ivan Okorn, Marko Nagode, Jernej Klemenc, Simon Oman
Summary: The study found that working load affects the dynamic loading of bolts, and high washers significantly increase the fatigue life of bolts.
Article
Chemistry, Analytical
Angelika Wronkowicz-Katunin, Andrzej Katunin, Marko Nagode, Jernej Klemenc
Summary: The authors proposed a method based on X-ray computed tomography images to accurately identify and differentiate different types of damage in composite structures, providing higher accuracy in predicting structural residual life.
Article
Engineering, Mechanical
Michal Bartosak, Marko Nagode, Jernej Klemenc, Karel Doubrava, Domen Seruga
Summary: This article proposes a new approach for modeling the stress-strain response of the Inconel 718 super alloy under isothermal Low-Cycle Fatigue loading, utilizing the Prandtl operator approach with modifications to simulate strain range dependent cyclic softening. The introduced modifications maintain the advantages of the Prandtl operators and enhance the simulation capabilities for complex nonlinear mechanical behavior, as demonstrated in various strain controlled tests at 500 C.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Materials Science, Characterization & Testing
Tadej Kocjan, Marko Nagode, Jernej Klemenc, Simon Oman
Summary: Rubber fatigue crack growth tests are a faster and less expensive method for characterizing fatigue behavior compared to fatigue crack initiation tests. This study investigated the possibility of using a new specimen grip geometry for crack growth tests and evaluated different variations of crack growth predictor parameters and crack growth angles. The results showed that the simplified crack growth predictor provided similar results to tearing energy, and using the Euclidean length of crack growth increments yielded better results than their horizontal projection.
Article
Mathematics
Branislav Panic, Marko Nagode, Jernej Klemenc, Simon Oman
Summary: Unsupervised image segmentation is an important task in computer vision systems, and a mixture model can be used to obtain segmented images. However, problems arise when the optimal mixture model contains a large number of components. This paper investigates methods for merging the components of the mixture model and their usefulness for unsupervised image segmentation.
Article
Polymer Science
Ales Gosar, Igor Emri, Jernej Klemenc, Marko Nagode, Simon Oman
Summary: This study investigates the vibration-damping properties of prestressed granular material, and finds that granular form provides better vibration-damping performance compared to bulk material. This improvement is achieved through the interaction of two effects: the pressure-frequency superposition principle at the molecular scale and the physical interactions between the granules (force-chain network) at the macro scale. Further improvements can be achieved by varying the material of the granules and applying a lubricant to facilitate reorganization of the force-chain network.
Article
Materials Science, Multidisciplinary
Ales Durjava, Marko Nagode, Domen Seruga
Summary: Polymers are rapidly replacing metals in structural applications. This study focused on polyamides as a substitute for metals in low-cycle fatigue applications. The research aimed to determine whether natural PA6 and glass-fibre-reinforced PA66 GF30 follow the memory rules during variable amplitude loading. The results showed that both polymers exhibited applicability of memory rules.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Computer Science, Interdisciplinary Applications
Marko Nagode, Branislav Panic, Jernej Klemenc, Simon Oman
Summary: Fault detection and classification is crucial in assessing the health status of structures and systems. This paper focuses on the use of statistical methods and the open-source R programming language for fault detection and classification. By expanding the rebmix package, accurate estimation of Gaussian mixture models was achieved, leading to promising results in practical applications.
COMPUTERS & INDUSTRIAL ENGINEERING
(2023)
Article
Mathematics
Branislav Panic, Marko Nagode, Jernej Klemenc, Simon Oman
Summary: This study investigates the usefulness of combining two clustering methods for unsupervised image segmentation and proposes a label noise correction approach. The results show that the proposed method outperforms other clustering methods on different objects, shapes, colorization, and noise.
Article
Engineering, Multidisciplinary
Martin Mikelj, Marko Nagode, Jernej Klemenc, Domen Seruga
Summary: An improved geometry of cast-iron manhole covers is proposed and analyzed from an operational strength point of view in this study. Numerical simulations reveal the suitability of the improved cover geometry.
Article
Chemistry, Analytical
Andrzej Katunin, Marko Nagode, Simon Oman, Adam Cholewa, Krzysztof Dragan
Summary: This study proposed a method to monitor hidden corrosion growth in metallic aircraft structures using a sequence of D-Sight images, by analyzing the images through geometric transforms and segmentation techniques to eliminate the influence of measurement conditions.
Article
Engineering, Multidisciplinary
Domen Seruga, Matija Kavcic, Jernej Klemenc, Marko Nagode
Summary: This study analyzes the impact of heat treatment on simulations of structural components and their behavior during operation. A starter clutch barrel is analyzed with heat treatment simulation followed by structural analysis during operation, showing that heat treatment introduces favorable compressive stresses and reduces effective stress amplitude during operation. The results emphasize the importance of considering heat treatment in the early stages of R&D process to ensure accurate predictions of structural component behavior.
