Article
Engineering, Mechanical
Mengen Liu, Antonio Carlos de Oliveira Miranda, Marcelo Avelar Antunes, Marco Antonio Meggiolaro, Jaime Tupiassu Pinho de Castro
Summary: This study proposes a mechanical methodology to evaluate the actual notch effects in fatigue strength, considering the elastoplastic stress and strain fields as well as the tolerance of short cracks due to local plasticity. The methodology calculates the actual fatigue stress concentration factor value.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
A. Nourian-Avval, M. M. Khonsari
Summary: This paper focuses on the rapid prediction of medium- and high-cycle fatigue performance of materials using the thermography approach. A model is proposed to estimate the damaging and non-damaging parts of heat dissipation during cyclic loading, and the concept of fracture fatigue entropy is utilized to quickly generate stress-life diagrams. It is mathematically shown that dissipating energy is directly proportional to steady-state temperature, enabling the prediction of fatigue performance by measuring steady-state temperatures during stepwise testing.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Yifei Yu, Xianjun Pei, Ping Wang, Pingsha Dong, Hongyuan Fang
Summary: This paper presents the Notch Structural Stress method, which reflects the impact of the notch effect on fatigue crack propagation lives. The validity of the method is verified through experiments, and it is found that the Notch Structural Stress parameter provides a more effective consolidation of fatigue data under different notch conditions.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Zhengping He, Bingzhi Chen, Xiangwei Li
Summary: The effective notch stress method considers the notch effect and solves the stress singularity in FEA by setting a virtual notch radius. However, this method has limitations such as inaccurate calculation results affected by the virtual radius and modeling difficulty. The recommended structural stress method based on fracture mechanics has no such limitation and also considers the notch effect and stress singularity. Two engineering cases were compared to demonstrate the engineering applicability of the two methods, and the results showed that the structural stress method has better engineering applicability and is worth popularizing.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
A. Mahmoudi, M. M. Khonsari
Summary: This research proposes a simple and efficient method for extracting the fatigue curve of materials within the framework of thermodynamics. By measuring the temperature rise, the fatigue life of the material can be predicted and the S-N curve can be created successfully.
EXPERIMENTAL MECHANICS
(2023)
Article
Engineering, Mechanical
Arash P. Jirandehi, M. M. Khonsari
Summary: A new technique for predicting the fatigue life of metals based on microstructure-sensitive estimation of plastic strain energy per cycle has been developed. The method was applied to low-carbon steel and aluminum specimens, showing realistic prediction of fatigue life for metallic specimens.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
Ali Mahmoudi, Michael M. Khonsari
Summary: This article discusses four different experimental approaches for rapidly estimating the fatigue limit (endurance limit) based on energy dissipation during cyclic loading. These approaches utilize energy dissipation and thermography, and can accurately evaluate the fatigue limit of a material through fatigue testing on a single specimen. The results show that the trend of energy dissipation can be used to predict the fatigue limit by observing changes in released energy due to damage accumulation at stress levels above the fatigue limit. Experimental results on CS 1018 and SS 304 specimens are presented to demonstrate the efficacy of the proposed methods.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Marta De Giorgi, Riccardo Nobile, Fania Palano
Summary: This study presents a new method based on thermographic data for determining the fatigue notch coefficient k(f) in composite materials with various notch geometries. The innovative aspect lies in applying a thermographic procedure to calculate k(f) for circular, U, and V notches in composite materials. The research provides a database of k(f) values for different laminates and notch geometries, offering a quicker way to collect relevant data.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Multidisciplinary
J. Y. Jang, M. M. Khonsari
Summary: Fracture due to cyclic actuation occurs when the accumulated entropy generation reaches a critical threshold known as the fracture fatigue entropy (FFE). The study examines the contribution of mechanisms such as supplied work, damage energy, cold work, and internal friction to fatigue damage using an irreversible thermodynamic framework and provides experimental evidence for the validity of the formulations. The formulations accurately capture the evolution of temperature and reveal that the experimentally observed abrupt temperature rise just before fracture is due to the rapid increase in damage and can be predicted.
MECHANICS OF MATERIALS
(2021)
Article
Engineering, Mechanical
I Perez, A. Madariaga, P. J. Arrazola, M. Cuesta, D. Soriano
Summary: The properties of the final surface layer are affected by machining operations, impacting on functional performance, especially fatigue behavior. Surface topography is a major parameter affecting fatigue behavior. Stress concentration factors K-t can provide a reliable estimation of the impact on fatigue behavior, with FE simulations accurately calculating them for 2D roughness profiles. A new analytical method aims to calculate stress concentration factor K-t for 3D surfaces, reducing computing time significantly compared to FE models.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Mechanical
Paolo Ferro, Keke Tang, Filippo Berto
Summary: This study investigates the influence of process parameters on the distribution of residual asymptotic stress using a 3D numerical modeling of the welding process. The computational welding mechanics and the peak stress method were combined to calculate the residual Notch Stress Intensity Factors (R-NSIF) as a function of power input. The results are summarized in terms of heat input and discussed in relation to future guidelines proposed for designers seeking to optimize the welding process for improved fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Thermodynamics
Yuan Cai, Jiyang Fu, Nan Wu, Chao Xiong, Airong Liu, Yuncheng He
Summary: In this study, a novel piezoelectric energy harvester with a curved panel is proposed, which can efficiently convert vibration energy into electricity through bistable behavior and alleviate fatigue damage caused by stress concentration. The design considers key parameters such as panel thicknesses, mass block, excitation frequency, and load resistance. Experimental results show that the harvester achieves high voltages and power output.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Engineering, Mechanical
Kai Suzuki, Shigeru Hamada, Motomichi Koyama, Kaneaki Tsuzaki, Hiroshi Noguchi
Summary: Fatigue tests and analysis on a high-entropy alloy revealed a transition in fatigue crack extension mode based on the severity of strain concentration.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
C. Danekas, S. Heikebruegge, J. Schubnell, P. Schaumann, B. Breidenstein, B. Bergmann
Summary: This study demonstrates that deep rolling, a mechanical surface treatment method, can significantly improve the fatigue life of welded joints, especially when a larger tool diameter is used.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Jiazhi Liu, Xintian Liu
Summary: By using infrared thermography to record the surface temperatures of specimens under different loading amplitudes and frequencies, the rates of entropy generation and cumulative entropy are calculated, and a relationship between fatigue life and entropy is established. The results show that under the same loading frequency, the entropy generation rate is proportional to the loading amplitude, the fatigue cycle is relatively low, and the cumulative entropy is inversely proportional to the loading amplitude. The cumulative entropy is only related to the loading amplitude, but not the loading frequency. A fatigue life prediction model based on the thermodynamic entropy of metals is established for the real-time assessment of fatigue damage of metal components.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Behnam Hajshirmohammadi, Michael M. Khonsari
Summary: An online approach using thermoelectricity was proposed to predict the fatigue life of metallic specimens under cyclic loading. The methodology was validated with experimental results, showing a practical methodology for early prediction of fatigue. The correlation between thermoelastic potential and fatigue life was demonstrated in low-carbon steel 1018 specimens measured via an infrared camera.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Arash P. Jirandehi, M. M. Khonsari
Summary: A statistical method is presented for estimating the plastic strain energy per cycle in metals under fatigue. The distribution of plastic strain under cyclic loading follows a two-parameter Weibull probability function and a second probability function is incorporated to account for different crystallographic directions. Results from a thermodynamically based model and a finite element model support the predictions made using the statistical method.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
A. Nourian-Avval, M. M. Khonsari
Summary: This paper proposes a model for predicting fatigue life under multiaxial loading based on dissipated heat during fatigue tests, evaluating fatigue damage by considering different rates of dissipated energy under various multiaxial loadings. The predictive capability of the models is confirmed through comparison with experimental fatigue results.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
M. Mehdizadeh, M. M. Khonsari
Summary: The study presented an experimental and theoretical analysis of low carbon steel 1018 subjected to multiaxial loading, showing that different loading conditions affect fatigue life. The use of thermography for fatigue life prediction was more accurate than hysteresis loops in capturing specimens' fatigue life under multiaxial fatigue loading.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Joonyoung Jang, Michael M. Khonsari
Summary: A new nonlinear fatigue damage accumulation model is developed in this paper, which considers the loading sequence effect and predicts the rate of damage by introducing a loading sequence parameter. The applicability of the proposed model is validated using nine sets of independent experimental measurements of fatigue life under multiple loading sequences, showing that the predictions are in agreement with the measured results and providing a reliable estimation of fatigue life.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Review
Engineering, Mechanical
Arash P. Jirandehi, Michael M. Khonsari
Summary: Recent progress in microstructure-sensitive research has led to insights on estimating fatigue damage and predicting useful life. A computational crystal plasticity approach incorporating statistical representations of material microstructure and a new thermodynamically based framework has been suggested.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Review
Physics, Multidisciplinary
Lijesh Koottaparambil, M. M. Khonsari
Summary: The study demonstrates that through a thermodynamic framework, various complex scenarios of frictional wear can be properly characterized, including unidirectional, bidirectional motions, transient operating conditions, and variable loading/speed sequencing.
Article
Materials Science, Composites
Ali Mahmoudi, Michael M. Khonsari
Summary: A new approach utilizing the concepts of kinetic strength and fracture fatigue entropy can reliably predict the fatigue life of laminated composites by considering the temperature and time dependence through Zhurkov's model.
JOURNAL OF COMPOSITE MATERIALS
(2022)
Article
Engineering, Mechanical
Ali Mahmoudi, M. M. Khonsari
Summary: A new method based on the fracture fatigue entropy (FFE) criterion is proposed to predict the fatigue life of metals. This method utilizes the concept of kinetic strength of solid materials to rapidly predict the cyclic plastic strain energy and temperature evolution. Experimental results for Al 7075-T6, LCS 1018, API 5L X52, and MCS 1045 are compared with theoretical predictions, demonstrating that this model can reliably predict the temperature evolution, plastic strain energy dissipation, and fatigue life of metals.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Arash P. Jirandehi, Ali Haghshenas, M. M. Khonsari
Summary: In this study, fully-reversed bending fatigue and impulse excitation tests were conducted to investigate the behavior of High Carbon Steel (HCS) at different environmental temperatures. It was found that with increasing environmental temperature, the specimens tended to become more brittle, leading to a decrease in fatigue life.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Chemical
Soroosh Salehi, Sahar Ghatrehsamani, Saleh Akbarzadeh, M. M. Khonsari
Summary: This paper presents an experimental procedure and a thermodynamic methodology for evaluating adhesive wear in systems with variable and sequential speeds. The continuum damage mechanics (CDM) is used to estimate the probability of asperities forming wear particles and derive the wear coefficient. The results show that the wear coefficient in descending cases is higher than in ascending velocity experiments. Additionally, Archard's law is not suitable for predicting wear volume in situations with variable speeds.
Article
Physics, Multidisciplinary
Mohammad A. Amooie, K. P. Lijesh, Ali Mahmoudi, Elaheh Azizian-Farsani, Michael M. Khonsari
Summary: The effect of sudden variations in working modes and fatigue behavior of CS 1018 is studied using a general model based on the concept of fracture fatigue entropy (FFE). Fully reversed bending tests are conducted on dog bone specimens with variable frequency tests to simulate fluctuating working conditions. The results show that regardless of frequency changes, FFE remains constant and within a narrow band range, similar to a constant frequency.
Article
Engineering, Mechanical
Mohammad A. Amooie, M. M. Khonsari
Summary: This study investigates the fracture behavior of carbon steel 1018 in low-temperature environments. Fully-reversed bending experimental tests were performed to examine the efficacy of using Fracture Fatigue Entropy (FFE) concept for predicting fatigue life at different environmental temperatures. The results show that lower operating temperatures can improve fatigue life of carbon steel. Additionally, FFE remains nearly constant and can be used for reliable prediction of fatigue life at different environmental temperatures. Illustrative examples are provided to demonstrate the utility of this approach for prediction purposes.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Mechanics
A. Mahmoudi, M. R. Khosravani, M. M. Khonsari, Tamara Reinicke
Summary: This study investigates the accumulated entropy at the crack tip of a semi-circular bending (SCB) specimen to determine the threshold for material fracture and interatomic debonding. The plastic flow at the crack tip is measured using the Digital Image Correlation (DIC) technique and strain maps superposed to SCB specimens. The generated entropy at the crack tip reaches a critical limit, beyond which bond breakage occurs, leading to crack surface propagation.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Ali Mahmoudi, Mohammad A. Amooie, Lijesh Koottaparambil, Michael M. Khonsari
Summary: This study introduces a reliable technique for predicting the remaining useful life of components by measuring the temperature signature when the operating frequency is rapidly changed. The approach is validated through fatigue tests on stainless steel specimens. The method allows for predicting the remaining useful life at different operating frequencies.
Article
Engineering, Mechanical
Miloslav Kepka, Miloslav Kepka Jr, Radovan Minich
Summary: This paper focuses on the fatigue life evaluation of the bodywork of a new articulated electric (battery) bus. The findings resulted in recommendations to improve the operational reliability of a particular vehicle and provided challenges for future research.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
T. Dusautoir, B. Berthel, S. Fouvry, P. Matzen, K-D. Meck
Summary: This study investigates the impact of post-processing treatments on the fatigue limit of additive manufactured Ti-6Al-4V under stress gradients, with a focus on surface integrity.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Zhuofan Xia, Di Wu, Xiaochen Zhang, Jianqiu Wang, En -Hou Han
Summary: The study reveals the surface-initiated rolling contact fatigue (RCF) failure mechanism under heavy load and initial high roughness surface. The results indicate that precursor of collapsed morphology and nanocrystalline layer are the main factors causing lower RCF life with high roughness compared to low roughness surfaces. The spalling failure initiating from low roughness surface under heavy load is strongly dependent on surface plastic deformation.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Daniel Gren, Knut Andreas Meyer
Summary: Rolling contact loading can cause plastic deformation and fatigue cracks. Current rail standards do not consider the effect of plasticity on mechanical behavior. This study proposes a new method for evaluating the fatigue life of deformed material and finds that superimposed compressive axial loads can increase fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
R. Kumar, S. Sanyal, J. Bhagyaraj, E. Hari Krishna, S. Mukherjee, K. Prasad, S. Mandal
Summary: This study investigates the thermomechanical fatigue (TMF) behavior of Timetal 834 alloy under different loading conditions. The results show that the alloy exhibits different cyclic hardening and softening responses at different strain amplitudes. The strain amplitude and phase angle have significant effects on the TMF life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Kai Donnerbauer, Tobias Bill, Peter Starke, Ruth Acosta, Bharath Yerrapa, Christian Boller, Klaus Heckmann, Frank Walther
Summary: Given the aging of nuclear power plants, it is important to develop methods for evaluating the integrity of components and structures in nuclear engineering. Suitable nondestructive testing methods can detect material degradation and determine its fatigue life. This study utilized various NDT parameters and scanning electron microscopic methods to explore the relationship between microstructure evolution and NDT data.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Liuyong He, Jiang Zheng, Tianjiao Li, Houkun Zhou, Lihong Xia, Bin Jiang
Summary: This study quantitatively analyzed the effects of precipitates on the deformation mode, cracking mode, and mechanical behavior of WE54 magnesium alloy during low-cycle fatigue. It was found that precipitates promoted the activation of dislocation slip and suppressed the activation of twinning, affecting the cracking mode and mechanical behavior.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Xiangkang Zeng, Conghui Zhang, Wenguang Zhu, Mingliang Zhu, Tongguang Zhai, Xiaomei He, Kangkai Song, Zhuohang Xie
Summary: The cyclic deformation behaviors and damage mechanisms of pure Zr were investigated. The cyclic stress response was mainly influenced by substructure evolutions. Prismatic < a > dislocation slip was identified as the dominant deformation mechanism. Fatigue damage was not only influenced by the initial texture, but also other factors.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Jingyu Yang, Bingbing Li, Yiming Zheng, Gang Chen, Xu Chen
Summary: Heat treatment is used to improve the low-cycle fatigue performance of additive manufactured 316LN stainless steel. The heat-treated material demonstrates initially cyclic hardening followed by softening behavior, and shows a stronger resistance to crack propagation compared to the as-built material, resulting in a longer fatigue life.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Lang Zou, Dongfang Zeng, Xiong Chen, Jun Li, Hai Zhao, Liantao Lu
Summary: This study investigates the competitive relationship between fretting fatigue and plain fatigue in press-fitted railway axles. By changing the depth of the stress relief groove, the plain fatigue limit and fretting fatigue strength were tested. Detailed information was gathered, and an evaluation methodology integrating finite element simulation and the Modified Wohler Curve Method was established. The study concludes that the optimal groove depth, which balances the anti-fatigue capabilities, depends on the number of test cycles.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Davide Leonetti, Koji Kinoshita, Yukina Takai, Alain Nussbaumer
Summary: This paper investigates the fatigue behavior of non-load-carrying transverse welded steel attachments, including fatigue crack monitoring and fracture surface analysis under constant and variable amplitude loading. A procedure is proposed to obtain a Markov transition matrix based on the measured strain signal and to randomly resample the stress history for variable amplitude fatigue tests.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Zhe Zhang, Bing Yang, Yuedong Wang, Shoune Xiao
Summary: This paper presents a method for designing fatigue life prediction models with small sample sizes by handling limited sample data. The method integrates the equivalent structural stress method with the maximum likelihood estimation method and adds reliability verification, resulting in enhanced goodness of fit, stability, and optimized sample quantity.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Cooper K. Hansen, Gary F. Whelan, Jacob D. Hochhalter
Summary: This paper presents a method to address the computational demand issue of computing FIPs using CPFEM by developing an interpretable machine learning model. Genetic programming is used to evolve interpretable expressions of FIPs from microstructure features, and these models can serve as efficient substitutes for CPFEM and be easily integrated into engineering workflows.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Luca Susmel
Summary: This paper discusses the problem of estimating notch fatigue limits using machine learning. The results show that machine learning is a promising approach for designing notched components against fatigue. The accuracy in estimating the fatigue limit can be increased by increasing the size and quality of the calibration dataset, as well as including additional input features.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)
Article
Engineering, Mechanical
Kefeng Gao, Guoqi Tan, Yanyan Liu, Qiang Wang, Qian Tang, Xuegang Wang, Qiqiang Duan, Zengqian Liu, Zhe Yi, Zhefeng Zhang
Summary: Bioinspired architectures have significant effects on material enhancement. This study investigates the fatigue properties of bioinspired ceramic-polymer composites and natural nacre, revealing the close relationship between architectural types, orientations, fatigue performance, and damage mechanisms.
INTERNATIONAL JOURNAL OF FATIGUE
(2024)