Article
Materials Science, Multidisciplinary
C. Lavogiez, C. Dureau, Y. Nadot, P. Villechaise, S. Hemery
Summary: The fatigue behavior of Ti-6Al-4V with a bi-modal microstructure was investigated using different waveforms, load ratios, and frequencies. It was found that cracks were initiated along (0001) twist grain boundaries, which is consistent with prior studies. The results also showed that the critical microstructural configurations were not sensitive to environmental factors, free surfaces, loading conditions, and microstructure and composition.
Article
Materials Science, Multidisciplinary
Zhihong Wu, Hongchao Kou, Nana Chen, Zhixin Zhang, Fengming Qiang, Jiangkun Fan, Bin Tang, Jinshan Li
Summary: The study investigated the effect of microstructure features on the high-cycle fatigue behavior of Ti-7Mo-3Nb-3Cr-3Al (Ti-7333) alloy. It was found that fatigue strength is closely related to microstructure features, especially the alpha(p) percentage. The alloy with lower alpha(p) percentage exhibited higher scatter in fatigue data and bimodal fatigue behavior.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Yanli Song, Zhongqi Wang, Yongqing Yu, Wenlin Wu, Zhongmei Wang, Jue Lu, Qian Sun, Lechun Xie, Lin Hua
Summary: A novel electroshock treatment method is proposed to improve the service life of titanium alloys. Experimental results show that the fatigue life of the alloys can be increased by the appropriate electroshock treatment. The microstructural evolution and nanoscale phase transformation induced by the treatment contribute to the improved fatigue life.
MATERIALS & DESIGN
(2022)
Article
Engineering, Mechanical
S. Hemery, J. C. Stinville
Summary: This study monitored the microstructurally small crack growth in Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo with equiaxed and bimodal microstructures. The influence of microstructure on the lifetime variability observed in Ti alloys was evaluated, and primary alpha grains, basal plane cracking, and misalignment across boundaries were identified as key features for high crack growth rates. Dwell periods were found to induce significant small crack acceleration.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Nanoscience & Nanotechnology
Zilu Xu, Chaowen Huang, Changsheng Tan, Mingpan Wan, Yongqing Zhao, Junqing Ye, Weidong Zeng
Summary: The cyclic deformation behavior of Ti-5Al-5Mo-5V-3Cr-1Zr alloy was significantly influenced by the strain amplitude and microstructure, showing different cyclic softening rates between bimodal microstructure (BM) and lamellar microstructure (LM). At low strain levels, BM exhibited lasting hardening due to multiple slip systems, while LM showed slight softening attributed to the activation of twins. However, at high strain levels, both BM and LM experienced dislocation annihilation and twinning, leading to a larger cyclic softening rate in BM.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Luopeng Xu, Rulun Zhang, Mengquan Hao, Lei Xiong, Qin Jiang, Zhixin Li, Qingyuan Wang, Xiaopeng Wang
Summary: A data-driven machine learning method is proposed to predict the low-cycle fatigue (LCF) life of Nickel-based superalloys, which overcomes the limitations of empirical formulas. The method integrates three characteristics of the superalloys: chemical composition, heat treatment process, and experimental parameters, to construct a unified fatigue life prediction dataset. Various machine-learning models, including Random Forest, Artificial Neural Network, Support Vector Machine, and a Genetic Algorithm-based Random Forest, accurately predict the LCF life, with GA-RF performing the best. The proposed method efficiently maps feature-life relationships for Nickel-based superalloys' LCF life, reducing experimental time and cost and promising applications in alloy design and manufacture.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Mechanics
Siyao Zhu, Yue Zhang, Xin Chen, Yuhuai He, Wei Xu
Summary: The study introduces a multi-algorithm integration machine learning approach named Auto_Gluon (AG) to predict the high cycle fatigue life of a titanium alloy TC17 based on numerous experimental fatigue data. The prediction accuracy of AG is shown to be better than other commonly-used machine learning models. The specimen properties are identified as the most significant category of factors influencing the fatigue life of TC17.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Jugan Zhang, Huihan Chen, Hanwei Fu, Yinan Cui, Chenchong Wang, Hao Chen, Zhigang Yang, Wenquan Cao, Jianxiong Liang, Chi Zhang
Summary: High-strength steels with large numbers of spherical carbides greatly affect fatigue performance. Previous studies suggested that refining carbides could improve fatigue performance, but this may not be true for submicron sized carbides. This study found that an optimum submicron carbide size exists and investigated the mechanism behind its effect on fatigue performance. Based on these findings, a new quantitative evaluation model was proposed, providing theoretical guidance for the microstructure design of submicron carbides.
Article
Nanoscience & Nanotechnology
Xiaolu Gui, Guhui Gao, Baifeng An, R. D. K. Misra, Bingzhe Bai
Summary: The study investigated the effects of inclusion size and microstructural features on HCF/VHCF in a B/M steel. It was found that fatigue crack initiation was mainly influenced by inclusions, with the majority of fatigue life consumed by the crack initiation process regardless of the source of the crack. The ratio of fatigue crack initiation life to total fatigue life exhibited a wide scatter due to variations in the B/M hierarchical structure within individual prior austenite grains when cracks initiated from sub-surface microstructure.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Crystallography
Baohua Nie, Yu Song, Xianyi Huang, Haiying Qi, Zihua Zhao, Dongchu Chen
Summary: In this paper, the low cycle fatigue (LCF) behaviors of TC21 alloy with a bi-lamellar basketweave microstructure were investigated. The cyclic stress-strain as well as the strain-life equations were obtained. The fatigue life decreased significantly with an increasing total strain, and the cyclic softening behavior was interpreted by cyclic back stress and friction stress.
Article
Crystallography
Songlin Shen, Mei Zhan, Pengfei Gao, Wenshuo Hao, Fionn P. E. Dunne, Zebang Zheng
Summary: This study conducted dwell fatigue tests on IMI834 titanium alloy to evaluate the microstructural effects on thermal-mechanical alleviation of cold dwell fatigue at low temperatures. The findings contribute to a better understanding of the mechanisms behind thermal-mechanical alleviation.
Article
Engineering, Mechanical
Gen Li, Lei Ke, Xuechong Ren, Chengqi Sun
Summary: The fracture surface of TC17 alloy varies in morphology depending on the stress ratio, with facet characteristic at high stress ratio and rough area morphology at low stress ratio. Walker's equation is found to be more accurate than Goodman's equation and Smith-Watson-Topper's equation for predicting the effect of stress ratio on high cycle and very high cycle fatigue strength.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Ruyue You, Mengmeng Zhang, Jianke Qiu, Chao Fang, Chunling Zhao, Bo Lu, Haibin Ji, Yingjie Ma, Jiafeng Lei, Rui Yang
Summary: This study investigates the effects of dwell period and microstructural conditions on dwell sensitivity in titanium components of gas turbine engines. The results show that dwell time and crystal orientation distribution have significant influences on dwell sensitivity, with a saturation point reached at 120 seconds. Extending the dwell time further increases dwell sensitivity in locations with low sensitivity.
Article
Chemistry, Physical
Bohan Wang, Li Cheng, Dongchun Li
Summary: Ultrasonic fatigue tests were conducted on TC4 titanium alloy specimens obtained by different forging processes, showing that they had different S-N curve shapes and no traditional fatigue limit. Among them, bimodal I exhibited the best comprehensive fatigue performance. SEM analysis revealed that fatigue cracks originated from surface or subsurface facets, indicating a transgranular quasi-cleavage fracture mechanism. EDS analysis showed that these facets were formed by the cleavage of primary alpha grains, and fatigue cracks originated from the preferred textures of primary alpha grains, rather than their clusters. The reasons for better equiaxed high-cycle-fatigue properties and better bimodal ultra-high-cycle-fatigue properties were analyzed from a microstructure perspective. Additionally, a fatigue life prediction for bimodal I based on energy was completed, showing good agreement with experimental data.
Article
Engineering, Mechanical
Anastasios G. Gavras, Anthony G. Spangenberger, Diana A. Lados
Summary: A study was conducted on the long and small fatigue crack growth mechanisms of various light structural aluminum and titanium alloys, leading to the development of a predictive model for microstructurally controlled small fatigue crack growth behavior, which agrees well with experimental data.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Multidisciplinary
Sourav Saha, Zhengtao Gan, Lin Cheng, Jiaying Gao, Orion L. Kafka, Xiaoyu Xie, Hengyang Li, Mahsa Tajdari, H. Alicia Kim, Wing Kam Liu
Summary: The unified AI-framework HiDeNN is proposed for solving challenging computational science and engineering problems, with demonstrated accuracy, efficiency, and versatility in three example problems. The framework shows potential for advanced engineering problems that require state-of-the-art AI approaches.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Computer Science, Interdisciplinary Applications
Modesar Shakoor
Summary: FEMS is a Finite Element Modeling Software that integrates mesh generation and adaption features to alleviate the difficulty of designing an FE mesh. It is targeted at engineers and scientists addressing localization problems in mechanics, with capabilities for handling internal interfaces in solid and fluid mechanics. FEMS automatically adapts the FE mesh during simulation to achieve the best accuracy for a prescribed number of nodes.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Mathematics, Interdisciplinary Applications
Xiao Ma, Modesar Shakoor, Dmytro Vasiukov, Stepan V. Lomov, Chung Hae Park
Summary: Numerical artifacts in FFT methods for multiphase elastic problems, caused by irregular discretization of the interface, are addressed in this study. An enhanced composite voxel method using the level-set technique is proposed to alleviate implementation difficulties and is particularly useful for non-parametrized interface representations.
COMPUTATIONAL MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
Dillon S. Watring, Jake T. Benzing, Orion L. Kafka, Li-Anne Liew, Newell H. Moser, John Erickson, Nikolas Hrabe, Ashley D. Spear
Summary: The modified void descriptor function (VDF) shows improved accuracy in predicting fracture locations in additive manufacturing components compared to the original method. Experimental results indicate that the new VDF can more accurately predict fracture locations and related performance parameters in AM components.
Article
Engineering, Multidisciplinary
Zeliang Liu
Summary: This study addresses the challenge of capturing material behaviors consistently across different length scales, proposing a deep material network model and a new cell-division scheme for scale transition. The research applies the multiscale model to simulations of various composite materials and provides experimental validation.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Computer Science, Interdisciplinary Applications
Modesar Shakoor, Chung Hae Park
Summary: A novel finite element framework is proposed for numerical simulation of two phase flows with surface tension, utilizing Level-Set method and P2 interpolation to enhance convergence rates, along with balanced-force surface force model to solve static problems and stabilized using variational multiscale framework. An anisotropic mesh adaption method is proposed for accuracy and optimal convergence rates, maintaining complexity fixed during simulation.
COMPUTERS & FLUIDS
(2021)
Article
Engineering, Mechanical
Nicholas Derimow, Keenan Hanson, Newell Moser, Orion L. Kafka, Jake T. Benzing, Nikolas Hrabe
Summary: The thickness of the surface layer can be controlled by varying the powder recovery blasting working distance and duration, resulting in a globular alpha/beta microstructure that improves fatigue strength. However, this trend is not observed for specimens with as-built surface roughness because globularization does not occur at the root of deep surface crevices.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Computer Science, Interdisciplinary Applications
Modesar Shakoor, Chung Hae Park
Summary: In this article, a multiscale approach is proposed for the computational homogenization of unsteady incompressible flows in domains containing small obstacles. The method, implemented using finite element analysis, shows robustness and efficiency in terms of computational cost and accuracy.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2023)
Article
Engineering, Multidisciplinary
Krushna Shinde, Vincent Itier, Jose Mennesson, Dmytro Vasiukov, Modesar Shakoor
Summary: This paper proposes an original approach based on an autoencoder neural network to construct a nonlinear Reduced-Order Model for a highly nonlinear brittle fracture problem. The effectiveness of the autoencoder in dimensionality reduction or compression of highly nonlinear data is demonstrated through a set of simulations. A complete deep learning framework is introduced to predict crack propagation patterns directly from the loading conditions. The proposed approach is validated using data sets generated for two problems with proportional and non-proportional loading conditions, evaluating its capabilities.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Mechanics
Xiao Ma, Yang Chen, Modesar Shakoor, Dmytro Vasiukov, Stepan V. Lomov, Chung Hae Park
Summary: This paper focuses on the numerical implementation of phase-field models of fracture using the Fast Fourier Transform based numerical method. The influence of a simplification in the phase-field evolution equation on heterogeneous materials is assessed and a complete formulation is proposed. The assessment shows that the simplified formulation leads to artificial diffusion of damage between different components, while the complete formulation suppresses this diffusion.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Mechanics
Orion L. Kafka, Cheng Yu, Puikei Cheng, Sarah J. Wolff, Jennifer L. Bennett, Edward J. Garboczi, Jian Cao, Xianghui Xiao, Wing Kam Liu
Summary: This study investigates the tensile properties of nickel-based alloy IN718, focusing on the spatial and orientation-based differences. The researchers used in-situ x-ray computed tomography to observe the internal pore populations and measured the evolution of pore shape during deformation. The results were compared to simulations using a computational crystal plasticity scheme, providing insights into the grain orientation in which the pore resides. The measurements show that pores tend to grow and elongate in the direction of loading, consistent with ductile deformation, and do not cause premature failure.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Manufacturing
E. Syerko, T. Schmidt, D. May, C. Binetruy, S. G. Advani, S. Lomov, L. Silva, S. Abaimov, N. Aissa, I. Akhatov, M. Ali, N. Asiaban, G. Broggi, J. Bruchon, B. Caglar, H. Digonnet, J. Dittmann, S. Drapier, A. Endruweit, A. Guilloux, R. Kandinskii, A. Leygue, B. Mahato, P. Martinez-Lera, M. Matveev, V. Michaud, P. Middendorf, N. Moulin, L. Orgeas, C. H. Park, S. Rief, M. Rouhi, I. Sergeichev, M. Shakoor, O. Shishkina, Y. Swolfs, M. Tahani, R. Umer, K. Vanclooster, R. Vorobyev
Summary: This paper presents the results of an international virtual permeability benchmark, which is a first contribution to permeability predictions for fibrous reinforcements based on real images. In this first stage, the focus was on the microscale computation of fiber bundle permeability. The scatter of the predicted axial permeability after the elimination of inconsistent results was found to be smaller (14%) than that of the transverse permeability (similar to 24%).
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Materials Science, Characterization & Testing
Ward L. Johnson, Jake T. Benzing, Orion L. Kafka, Newell H. Moser, Derek Harris, Jeremy J. Iten, Nik W. Hrabe
Summary: Acoustic nonlinearity and loss are positively correlated with porosity in laser powder bed fusion (L-PBF) produced aluminum parts. Nonlinear reverberation spectroscopy (NRS) with electromagnetic-acoustic transduction is used for acoustic measurements, allowing adaptability to complex geometries and quick inspection times. Porosity and microstructure are characterized using various techniques. The behavior of nonlinearity and loss under acoustic excitation indicates changes in defects without thermal excitation involvement and does not impede nondestructive qualification of additively manufactured parts.
NDT & E INTERNATIONAL
(2023)
Article
Chemistry, Physical
Romain Agogue, Modesar Shakoor, Pierre Beauchene, Chung Hae Park
Summary: This study presents a numerical analysis of the effects of race tracking on the formation of dry spots and the accuracy of permeability measurement during the resin-transfer-molding process. Randomly generated defects are assessed using a Monte Carlo simulation method in the numerical simulation of the mold-filling process. The influence of race tracking on unsaturated permeability measurement and dry spot formation is investigated on flat plates. The results show that race-tracking defects near the injection gate can increase the measured unsaturated permeability by up to 40%.
Article
Mechanics
Xiao Ma, Dmytro Vasiukov, Modesar Shakoor, Stepan V. Lomov, Chung Hae Park
Summary: This paper focuses on the numerical implementation of phase-field models of fracture using the Fast Fourier Transform (FFT) based numerical method. The choice of regularization length in phase-field models is important for both macroscopic mechanical behavior and local crack propagation patterns. Wu's phase-field model has been successful in reducing length sensitivity for homogeneous materials, and it has also been found to be more suitable than Miehe's model for brittle failure with the introduction of an elastic stage. The sensitivity of Wu's model for heterogeneous materials has also been investigated in this study.
ENGINEERING FRACTURE MECHANICS
(2023)
