Article
Materials Science, Multidisciplinary
Duncan W. MacLachlan, Vasilis Karamitros, Fionn P. E. Dunne
Summary: This paper proposes an engineering approach to the problem of fatigue crack initiation at the microstructural scale. The initiation of fatigue cracks is broken down into separate processes, and a fundamental approach to modelling these processes has been developed. The method successfully correlates with fatigue data for a specific material.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Engineering, Mechanical
Mengzhen Cao, Yang Liu, Fionn P. E. Dunne
Summary: A comparative study using crystal plasticity finite element modeling reveals that fatigue crack nucleation is highly sensitive to both lack of fusion and gas/keyhole pores in AlSi10Mg material. Lack of fusion pores, in particular, significantly reduces fatigue life at high stress levels.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Aerospace
Jian Wang, Caizhi Zhou
Summary: This paper utilizes the Crystal Plasticity Finite Element (CPFE) method and sub-modeling technology to investigate the effects of external excitations on the Crack Initiation Location (CIL) of fretting fatigue in Aluminum Alloy (AA) specimens. The relationship between Most Likely Cracked (MLC) site and CIL, as well as their migration and transformation, are described. The identification method of CIL is also discussed, providing theoretical and technical supports for anti-fretting fatigue design of AA components in service.
CHINESE JOURNAL OF AERONAUTICS
(2022)
Article
Engineering, Mechanical
Bowen Chen, Shigeru Hamada, Wanjia Li, Hiroshi Noguchi
Summary: A study on the influence of material and mechanical effects on the damage accumulation mode of fatigue crack propagation was conducted in a polycrystalline copper specimen using a crystal plasticity finite element method. The plastic normal strain localization ahead of the notch root, which is correlated with damage accumulation-fatigue crack propagation, was analyzed. Consequently, an equation for the critical grain size was formulated using the Schmid factor, misorientation angle, and plastic zone size to characterize the critical occurrence condition for damage accumulation-fatigue crack propagation. Additionally, a method for predicting the size of the damage accumulation-fatigue crack propagation region was proposed.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Zebang Zheng, Pandi Zhao, Mei Zhan, Hongwei Li, Yudong Lei, M. W. Fu
Summary: This study determines the threshold for fatigue crack nucleation in metallic sealing rings through an integrated experimental and numerical modeling approach. The fatigue lives under different service conditions were evaluated based on the evolution of local stored energy density. The conclusions provide theoretical guidance for the manufacturing of high-performance metallic sealing rings.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Jian Wang, Tianju Chen, Caizhi Zhou
Summary: A crystal plasticity finite element (CPFE) model was developed to simulate the fretting fatigue behavior of aluminum alloy 7075, with refined contact region using submodel technology and energy-based criterion for crack initiation prediction. Hotspots for fretting fatigue crack nucleation were identified based on maximum plastic strain energy density. The CPFE model demonstrated high accuracy in predicting fretting fatigue crack initiation, validated by experimental results.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Manufacturing
Somnath Ghosh, Jinlei Shen, Shravan Kotha, Pritam Chakraborty
Summary: This paper introduces a method called WATMUS, which can be used to model the fatigue crack nucleation mechanism of metallic materials at microstructural and structural scales. The method can significantly accelerate the solution of fatigue problems and has achieved good simulation results at multiple spatial scales.
INTEGRATING MATERIALS AND MANUFACTURING INNOVATION
(2021)
Article
Chemistry, Physical
Xin Jin, Run-Zi Wang, Yang Shu, Jia-Wen Fei, Jian-Feng Wen, Shan-Tung Tu
Summary: The paper proposes a multiscale numerical framework combining the crystal plastic frame with the meso-damage mechanisms to study the failure mechanisms of high-temperature components in power plants due to creep and fatigue. It can quantitatively describe the crack initiation life affected by factors such as average grain size, initial notch size, stress range, and holding time.
Article
Materials Science, Multidisciplinary
Zhen Wang, Chong Zhao, Jie Wang, Wenwang Wu, Xide Li
Summary: The creep-fatigue fracture behavior of SLM AlSi10Mg alloy at 500 degrees C was studied, and it was found that the lifetime decreased with increasing dwell time. The in-situ scanning electron microscopy images and fracture morphology were used to analyze the fracture evolution and reveal the creep-fatigue fracture mechanism. Additionally, crystal plasticity finite element simulation was utilized to explain the crack nucleation of the alloy under fatigue and dwell-fatigue conditions.
INTERNATIONAL JOURNAL OF FRACTURE
(2022)
Article
Engineering, Mechanical
Shengkun Wang, Zuoliang Ning, Peng Li, Mengqi Li, Qiang Lin, Hao Wu, Gang Chen
Summary: The fatigue crack nucleation mechanism of Ti-2Al-2.5Zr alloy was investigated using quasi in-situ tests coupled with crystal plasticity simulation. Digital image correlation based on scanning electron microscope (SEM-DIC) was used to validate the constitutive parameters in the crystal plasticity model. It was observed that transgranular and intergranular cracks nucleated inside grains and at grain boundaries respectively, and quasi transgranular cracks were induced by the adjacent microstructure or cracks. The slip direction of slip planes where transgranular cracks nucleated had an angle range of 20-55 degrees with the sample surface. Three factors for predicting intergranular cracks were identified and a slip shearing mechanism of grain boundaries was proposed. The results of crystal plasticity indicated a significant plastic strain difference at grain boundaries where intergranular cracks nucleated. The band averaging method showed better prediction ability than the grain averaging method, and a unified fatigue indicator parameter (FIP) combining accumulated plastic strain, strain incompatibility parameter (SIP), and the aforementioned crack prediction factors was proposed, improving the unified prediction ability for both transgranular and intergranular cracks.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Mechanical
Hamidreza Abdolvand
Summary: This paper describes in detail the incorporation of four different microstructure-sensitive damage mechanisms into a crystal plasticity finite element model. The performance of each model in predicting crack nucleation and propagation is studied by comparing the numerical results with experimental data. The results show that for different specimen textures, the principal stress and maximum slip methods can correctly predict the location and propagation direction of major cracks, while the energy method or principal plastic strain method mainly coincide with minor cracks or those that propagate at higher applied strains.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Mechanical
Yan Bin Pan, Fionn P. E. Dunne, Duncan W. MacLachlan
Summary: The crystal plasticity finite element (CPFE) method, in conjunction with a critical local stored energy criterion, successfully predicted crack nucleation life for a nickel superalloy RR1000. Fatigue behavior under different conditions was studied, and the results showed accurate predictions at high temperatures.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Marine
Kasumi Morita, Masashi Mouri, Riccardo Fincato, Seiichiro Tsutsumi
Summary: This study investigates the fatigue cyclic deformation behavior of mid-carbon steel using experimental and numerical methods. The material exhibits different uniaxial ratcheting behavior depending on loading history, with the FSS model successfully reproducing the nonlinear material behavior. The good agreement between experimental and numerical results demonstrates the reliability of the model in capturing a realistic material response in fatigue problems.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Yang Liu, Xiang Zhang, Caglar Oskay
Summary: This manuscript conducts a comparative study on different fatigue indicator parameters to evaluate their ability to predict the location of fatigue crack nucleation in near-alpha titanium alloy microstructures. The results show that some of the selected parameters can accurately predict the critical initiation locations, which are consistent with the fractography measurements.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Engineering, Mechanical
F. Zhu, M. L. Zhang, C. J. Zhang, P. F. He, Y. Dai
Summary: Combined low and high cycle loading has a significant impact on the fatigue performance of AISI 4140 steel compared to pure low or high cycle loading. This study investigated the combined low and high cycle fatigue responses of AISI 4140 steel at different frequency ratios (20%-30%) and stress amplitude ratios (100-1000). The results showed that higher stress amplitude and frequency ratios led to shorter fatigue life. A fatigue life prediction model was developed based on crystal plasticity theory and microstructure evolution parameters, which accurately predicted the fatigue life within thrice the scatter band.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Aniket Chakrabarty, Vivek Kumar Sahu, Anindya Das, Shreya Mukherjee, Nilesh Prakash Gurao, Pritam Chakraborty, Himadri Nandan Bar, Niloy Khutia
Summary: The scanning strategy in powder bed fusion has a measurable impact on the grain size and growth direction of produced parts. Tilted scan lines can lead to greater elongation in AlSi10Mg parts, while non-tilted lines result in higher tensile strength. Advanced characterization methods like EBSD and X-ray CT were used to analyze the microstructures of the alloys, providing insights into the deformation and hardening behavior of the specimens.
METALS AND MATERIALS INTERNATIONAL
(2022)
Article
Engineering, Multidisciplinary
Xiaofan Zhang, Yanrong Xiao, Christopher S. Meyer, Daniel J. O'Brien, Somnath Ghosh
Summary: This paper develops two-level parametrically-upscaled continuum damage mechanics models for woven composites. The models are thermodynamically consistent and integrate micro-/mesostructure to bridge length scales. The coefficients are determined using machine learning algorithms operating on a response database. The models are validated using ballistic impact experiments with good agreement.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Saikat Dan, Preetam Tarafder, Somnath Ghosh
Summary: In this paper, a novel finite deformation finite element (FE) model is developed to study the coupled electro-mechanical response and crack evolution in heterogeneous piezoelectric composite microstructures. The model incorporates a unified phase-field model with cohesive traction-separation laws to simulate crack propagation and interfacial decohesion in the presence of electro-mechanical fields. Degradation functions are employed to account for different electrical crack face conditions. An adaptive wavelet-enhanced hierarchical framework is implemented to improve the computational efficiency of the coupled electromechanical-phase-field FE solver. Numerical examples demonstrate the effectiveness of the model in capturing different failure mechanisms in piezoelectric materials and piezo-composite microstructures.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Jinlei Shen, Shravan Kotha, Ryan Noraas, Vasisht Venkatesh, Somnath Ghosh
Summary: This paper develops Parametrically Upscaled Constitutive Model (PUCM) and Parametrically Upscaled Crack Nucleation Model (PUCNM) for a commercially used a/6-phase Ti64 alloy to study the influence of microstructure on fatigue crack nucleation.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Mechanical
M. Pinz, J. T. Benzing, A. Pilchak, S. Ghosh
Summary: This paper develops an effective crystal plasticity model with porosity evolution for additively manufactured Ti-6Al-4V alloys. The model is calibrated and validated with experimental results, and can provide important insights into the underlying physics of this relatively new class of materials.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Engineering, Multidisciplinary
George Weber, Maxwell Pinz, Somnath Ghosh
Summary: This paper presents a concurrent multiscale modeling framework for developing parametrically-upscaled crystal plasticity models for crystalline metals with multiple phases in their intragranular microstructure. By combining physics-based modeling and machine learning methods, it enables analysis of deformation and failure in materials at multiple scales and provides location-specific design.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Mechanics
Yanrong Xiao, Xiaofan Zhang, Somnath Ghosh
Summary: This paper develops a validated 2-level parametrically-upscaled continuum damage mechanics (PUCDM) model for multiscale modeling of damage evolution in plain weave woven composites. The model accurately predicts the stress-strain and damage evolution with high computational efficiency. Machine learning methods are used to generate constitutive coefficients based on response variables from lower scale analysis.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Yanrong Xiao, Xiaofan Zhang, Somnath Ghosh
Summary: In this paper, the two-level parametrically-upscaled continuum damage mechanics models are applied for multiscale analysis of plain weave composite structures. The models are validated through experiments and parametric studies, and the effect of lower-scale morphology and material properties on the structural damage response of the woven composite beams is investigated.
COMPOSITE STRUCTURES
(2022)
Article
Polymer Science
Arunjyoti Sinha Roy, Nilanjan Mitra, Somnath Ghosh
Summary: This paper discusses the mechanisms of atomic-scale deformation in polyurea under applied loads, and explores the effects of strain rates, simulation constraints, and nanofillers on the overall response and properties of polyurea.
Article
Materials Science, Composites
Preetam Tarafder, Saikat Dan, Somnath Ghosh
Summary: This paper introduces a coupled electromechanical finite deformation phase field model for crack propagation and interfacial decohesion in multiphase piezoelectric composites with interfaces. The model incorporates cohesive traction-separation laws at the material interfaces and an anisotropic elastic stiffness function for the piezoelectric material. Numerical simulations demonstrate the efficacy of the model in capturing different failure mechanisms and investigating the effects of external electric fields and crack face conditions on crack evolution. Limited verification tests are also conducted, and the model is used to simulate fracture in nonuniform piezocomposite microstructures.
JOURNAL OF COMPOSITE MATERIALS
(2023)
Article
Materials Science, Composites
Chandra Prakash, Somnath Ghosh
Summary: This paper develops a Parametrically Upscaled Continuum Damage Mechanics (PUCDM) model for carbon fiber/epoxy matrix composites subjected to high strain-rate loading. The model takes into account the microstructural morphology and micro-inertia in its constitutive coefficients. By using a concurrent multiscale model, the effect of micro-inertia and stress wave interaction with the microstructure is considered. Simulations using the concurrent model analyze stress wave propagation and damage evolution in composite microstructures with different fiber volume fractions at multiple strain rates. Results show the importance of considering micro-inertia, strain rates, and microstructure morphology in the PUCDM-based stiffness and damage model parameters for high strain-rates above 10⁴ s⁻¹.
JOURNAL OF COMPOSITE MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jinlei Shen, Vasisht Venkatesh, Ryan Noraas, Somnath Ghosh
Summary: This paper develops a parametrically upscaled constitutive and crack nucleation modeling platform for predicting structural-scale fatigue crack nucleation in Ti-6Al-4V alloys with micro-texture regions (MTRs). The platform bridges micro and macro scales by incorporating representative aggregated microstructural parameters (RAMPs) in macroscopic constitutive relations. A novel RAMP k(MTR)(theta c) is proposed to quantitatively represent MTR intensity in the microstructure. The impact of MTR characteristics on fatigue crack nucleation is evaluated through SVR-aided Sobol analysis. Results show a reduction in nucleation life with a higher level of MTR intensity.
Article
Mechanics
Kishore Appunhi Nair, Somnath Ghosh
Summary: This paper develops a method for considering the influence of dislocations nucleating from a crack-tip on the plasticity evolution and crack propagation process. A model is created to transfer and propagate dislocations from the atomistic to continuum domain and generate a dataset of crack tip dislocation density evolution. The critical state variables affecting the evolution of crack tip dislocation density are inferred through Bayesian inference, and the evolution of dislocation density is derived using genetic programming based symbolic regression. The contribution of nucleated dislocations to effective plastic strain evolution at the crack tip is validated, showing the importance of this augmentation on crack evolution.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Syed Mustafa Kazim, Kartik Prasad, Pritam Chakraborty
Summary: This paper develops a crystal plasticity model to capture the dynamic strain aging (DSA) behavior of Timetal-834 alloy at high temperatures. The model successfully predicts the flow stress and DSA behavior, showing good agreement with experimental data. The model incorporates nested models and microstructural analysis to capture the microstructure-dependent DSA.
MECHANICS OF MATERIALS
(2023)
Article
Engineering, Multidisciplinary
S. Mustafa Kazim, Kartik Prasad, Pritam Chakraborty
Summary: The microstructure of near alpha and alpha + beta Ti alloys has a significant impact on mechanical properties, and is widely studied using crystal plasticity finite element method (CPFEM) analysis of polycrystalline representative volume elements (RVEs). Homogenized models may lead to inaccurate estimates of deformation behavior, and asymptotic expansion-based homogenization can be used to evaluate this inaccuracy.
MULTISCALE AND MULTIDISCIPLINARY MODELING EXPERIMENTS AND DESIGN
(2022)
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)
