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, Manufacturing
Arash P. Jirandehi, Behnam Hajshirmohammadi, Patricio Carrion, M. M. Khonsari, Nima Shamsaei, Shuai Shao
Summary: By testing additively manufactured Inconel 718 parts fabricated in different build orientations in a fatigue mode, it is found that vertically built specimens endure the most fatigue damage before failure, while diagonally built ones sustain the least. Additionally, a microstructure-sensitive algorithm is used to estimate the fatigue life under arbitrary load amplitudes with acceptable accuracy compared to experiments.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Mechanical
Arash P. Jirandehi, M. M. Khonsari, S. Guo, Paul Gradl
Summary: The efficacy of a newly developed microstructure-sensitive fatigue framework for additively manufactured materials is evaluated at different environmental temperatures. C-18150 copper alloy samples fabricated by Laser Powder Bed Fusion (L-PBF) are subjected to fatigue testing at room temperature, 204 degrees C, and 426 degrees C. The damage representative, plastic strain energy, is studied using cyclic stress-strain hysteresis loop area measurements and analyzed with a microstructure-sensitive algorithm. A thermodynamics-based framework is employed to calculate Fracture Fatigue Entropy (FFE) for assessing the materials' fatigue performance. The results from the hysteresis loop and microstructure-sensitive method show consistent trends and magnitudes.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Mohammad Rouhi Moghanlou, M. M. Khonsari
Summary: The study uses the kinetic concept to determine the fatigue life of materials and evaluate the fracture fatigue entropy. The results indicate a good agreement between the predicted model and experimental data, providing further evidence for the constancy of fracture fatigue entropy.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Zhichao Zhang, Linhang Li, Zhenglong Xu
Summary: This paper presents a hyperelastic-plastic coupled constitutive model for bonded and unbonded soils based on thermodynamics. The model can naturally predict state boundaries and failure surfaces of different soils, and reproduce various elasto-plastic coupling features.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Mechanics
Shu Zhang, Rui Ma, Yu Hu, Qingbin Li
Summary: The fatigue failure problem can be explained by fatigue stress-strain envelope, and using fatigue stress-strain for evaluation can eliminate the uncertainty in selecting fatigue criteria in engineering applications. However, the use of experimental fatigue envelope criterion based on stress-strain curve is limited to concrete and rocks, and it cannot predict the fatigue failure time. To improve the availability of fatigue stress-strain envelope criterion, a fatigue failure criterion is proposed based on the static constitutive curve as the limit value, which describes high-cycle and low-cycle fatigue failure through theoretical deduction and analysis of experimental results. The proposed criterion reveals the mechanism that fatigue life is dominated by fatigue failure stress-strain in the fatigue envelope surface. The comparison between calculated and experimental fatigue life shows that the proposed criterion effectively describes fatigue failure and has comprehensive application prospects.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Chunguo Zhang, Shuai Luan
Summary: This study proposes a method to measure equivalent residual stress in real time during fatigue cycling, which can monitor the residual stress in welded joints.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Xu Long, Ying Guo, Yutai Su, Kim S. Siow, Chuantong Chen
Summary: In this study, the damage evolution and accumulation of SAC305 solder under low-cycle fatigue loading were investigated. A fatigue damage model based on entropy generation was proposed and the physical damage mechanism of SAC305 solder was elucidated using optical microscopy.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Construction & Building Technology
Yu-Lei Bai, Shi-Jie Mei, Pengda Li, Junjie Xu
Summary: LRS FRP-confined concrete enhances the ultimate strength, ductility, and energy absorption capacity of concrete structures. The confining pressure at large deformation significantly affects the damage process of concrete. By analyzing the cyclic response, plastic strain and stress degradation were identified as key parameters influencing the behavior of LRS FRP-confined concrete.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Mechanical
Jagtar Singh, Greg Wheatley, Ricardo Branco, Fernando Ventura Antunes, Reza Masoudi Nejad, Filippo Berto
Summary: The present study investigates the influence of tensile pre-strain histories and strain ratio on the cyclic deformation behavior of 6061 aluminum alloy and 2024 aluminum alloy. The results indicate that the material exhibits cyclic strain-softening behavior, with the degree of softening increasing with higher strain ratios and lower strain amplitudes.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Materials Science, Multidisciplinary
Hsiao Wei Lee, Cemal Basaran
Summary: The study focuses on fatigue life prediction of metals using Unified Mechanics Theory (UMT), which incorporates Thermodynamic State Index (TSI) and fundamental equations of thermodynamics into the governing differential equations. This physics-based approach eliminates the need for empirical evolution functions obtained by curve fitting to fatigue test data.
MECHANICS OF MATERIALS
(2022)
Review
Materials Science, Multidisciplinary
Hsiao Wei Lee, Cemal Basaran
Summary: This review focuses on degradation, damage evolution, and fatigue models for various engineering materials, mostly metals and composites, with discussions on both empirical models and physics-based models, such as unified mechanics theory.
Article
Engineering, Electrical & Electronic
Xavier Zamora, Angel Cuadras
Summary: A new contactless entropy measurement system based on infrared sensors is proposed in this paper to monitor degradation processes and energy efficiency. The thermodynamics of entropy is experimentally inferred, and the entropy flow rate and generation rate are evaluated.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Nuclear Science & Technology
Lang Jiang, Xiyang Su, Liuyang Shen, Jun Zhou, Xingyi Zhang
Summary: This study investigated the damage evolution of Nb3Sn/Cu superconducting strand under asymmetric strain cycling. Results showed that higher strain ranges and peaks can accelerate damage evolution, especially at the early fatigue stage. A proposed model derived independent plastic damage evolution equations for Nb3Sn sub-elements and Cu matrix, which were validated to predict stiffness degeneration and fatigue life under asymmetric strain cycling.
FUSION ENGINEERING AND DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Matthias Droste, Sebastian Henkel, Horst Biermann, Anja Weidner
Summary: This study investigates metastable austenitic stainless steel during fatigue tests under strain control and focuses on the influence of different microstructures on fatigue life. Additionally, a proposed approach for calculating parameters based on strain-controlled tests is introduced to estimate fatigue life for materials undergoing secondary hardening due to martensitic phase transformation.
Article
Engineering, Mechanical
Jude A. Osara, Michael D. Bryant
TRIBOLOGY INTERNATIONAL
(2019)
Article
Thermodynamics
Jude A. Osara, Michael D. Bryant
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2020)
Article
Electrochemistry
Jude A. Osara, Michael D. Bryant
Summary: This study demonstrates a thermodynamics-based characterization of electrochemical power sources and introduces new performance/degradation factors. Results from various power source types are consistent, validating anticipated system behaviors and introducing a normalized DEG domain for comparative analysis.
ELECTROCHIMICA ACTA
(2021)
Article
Energy & Fuels
Jude A. Osara, Ofodike A. Ezekoye, Kevin C. Marr, Michael D. Bryant
Summary: The Degradation-Entropy Generation (DEG) methodology is used to cycle and characterize lithium-ion batteries, with comparisons made to Coulomb-counted capacity fade. DEG elements and coefficients were evaluated for battery performance and degradation analysis. The effect of cycling rate on these DEG elements was discussed using measured data from three same-model lithium-ion batteries. The results confirm that the DEG methodology aligns with established battery behaviors and thermodynamics laws, making it easily adaptable for battery analysis.
JOURNAL OF ENERGY STORAGE
(2021)
Article
Engineering, Mechanical
Jude A. Osara, Piet M. Lugt, Michael D. Bryant, Michael M. Khonsari
Summary: This study investigates the oxidation-thermal stability of lubricating greases using the ASTM 5483 standard and thermodynamic laws. A new model based on degradation-entropy generation (DEG) theorem is developed to predict the oxidation induction time. The results show that the high-pressure entropy transfer by oxygen mass flow is the primary contributor to oxidation induction time, and the DEG model accurately predicts induction times at different temperatures.
TRIBOLOGY TRANSACTIONS
(2022)
Article
Engineering, Mechanical
Pramod Shetty, Robert Jan Meijer, Jude A. Osara, Piet M. Lugt
Summary: This article presents a new method for measuring the film thickness in a rolling bearing and investigates the impact of speed on the film thickness.
TRIBOLOGY TRANSACTIONS
(2022)
Article
Engineering, Mechanical
Femke Hogenberk, Jude A. Osara, Dirk van den Ende, Piet M. Lugt
Summary: In this study, the bleed properties of five types of lubricating greases are quantified to investigate the changes in bleed rate over time. The results show that controlled shear ageing in a grease worker does not significantly affect the bleed rate at room temperature, unlike rheological and microstructural changes. A comparison with rolling bearing results suggests that ageing grease in a grease worker has minimal impact on the permeability of lubricating greases.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Electrochemistry
Jude A. Osara, Michael D. Bryant
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2019)
Article
Engineering, Multidisciplinary
Jude A. Osara, Michael D. Bryant
Article
Engineering, Multidisciplinary
Jude A. Osara