Article
Engineering, Mechanical
Bimal Das, Akhilendra Singh, Puja Ghosal, Ashish Priya, R. Rohith Kumar Reddy
Summary: The study investigates the impact of hydrogen charging on the transformation induced plasticity steel during strain-controlled low cycle fatigue (LCF). Hydrogen charging negatively affects the strain-controlled LCF lives. The uncharged specimen experiences cyclic hardening due to strain-induced martensitic transformation (SIMT), while the hydrogen charged specimen exhibits cyclic softening and suppresses cyclic hardening due to the large fraction of low angle grain boundaries. Additionally, the cyclic plasticity modeling using the Ohno-Wang kinematic hardening model accurately simulates the cyclic stress-strain hysteresis loop and cyclic softening curve of both uncharged and hydrogen charged specimens.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Siqi Li, Zhong Zhang, Rong Liu, Xijia Wu
Summary: In this research, microstructure-based modeling is used to predict the fatigue crack nucleation life of a nickel-based alloy, Haynes 282, under different strain amplitudes. A three-dimensional polycrystalline aggregate is constructed as the material representative volume element (RVE) using Voronoi tessellation with grain orientations assigned by random functions. The model successfully predicts the fatigue crack nucleation life of Haynes 282 alloy and estimates the scattering of the fatigue life. The effect of grain orientation on fatigue crack nucleation is also discussed.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Multidisciplinary
Yanyun Zhao, Haibo Cao, Shaojun Liu
Summary: The fatigue behavior of RAFM steel is strongly influenced by shear stress conditions and varies under different loading paths. Fatigue softening is observed under proportional multi-axial loading, while additional hardening is observed under non-proportional multi-axial cyclic loading related to dislocation activities.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Jin-Qun Zhu, Yi-Xin Lu, Lin-Gen Sun, Shu Huang, Lin-Bo Mei, Ming-Liang Zhu, Fu-Zhen Xuan
Summary: The fatigue crack growth behavior of Inconel 740H and Haynes 282 nickel-based alloys was investigated at different temperatures. The results showed an increased fatigue crack growth rate for both alloys, with Inconel 740H exhibiting an increased fatigue threshold at high temperatures. The presence of MC carbides, serrated grain boundaries, and twins affected the crack growth path. The interaction between the strengthening ?' phase and dislocations was different in the two alloys, with Haynes 282 exhibiting shear mechanisms and Inconel 740H exhibiting Orowan bypass mechanisms at elevated temperatures. The resistance of dislocation movement was reduced by cross slip, dislocation climbing, and entanglement, leading to accelerated damage accumulation. The different Cr content in the two alloys promoted the formation of different carbides and oxide layers, which played a role in the fatigue threshold at elevated temperatures.
MATERIALS CHARACTERIZATION
(2023)
Article
Engineering, Mechanical
Mengqi Li, Shengkun Wang, Jingtai Yu, Gang Chen
Summary: In this study, in-phase and out-of-phase thermomechanical fatigue (TMF) tests as well as isothermal fatigue (IF) tests were conducted to investigate the cyclic deformation behavior and fatigue life of Ti-2Al-2.5Zr alloy. The competition mechanism of back stress and friction stress was found to have an effect on the cyclic hardening/softening behavior. The fatigue life of TMF and IF showed slight differences at higher strain amplitudes, while it depended on loading modes at lower strain amplitudes due to the deviation in plastic strain energy density and peak stress.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
S. Arun Shankar, N. Arunachalam, C. Joseph, S. Natarajan
Summary: Current numerical prediction methods for determining geometric distortion in manufacturing are limited. This study proposes an innovative method to identify the critical factors for distortion and develops a finite element based framework to validate the hypothesis. The framework is applied to an experimental non-prismatic industrial part and supports the hypothesis that quenching is the most significant contributor to distortion in thin-walled parts made from Haynes 282 alloy. The framework/model provides valuable insights into the contributions of thermal gradients and material state towards part distortion, and overcomes the limitations of current numerical prediction methods.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Chemistry, Physical
Marco Pelegatti, Alex Lanzutti, Enrico Salvati, Jelena Srnec Novak, Francesco De Bona, Denis Benasciutti
Summary: This study focuses on the cyclic response and low-cycle fatigue performance of AISI 316L stainless steels at room temperature, providing design strain-life curves through experimental testing and parameter calibration. The statistical methodology presented appears to be an efficient tool for engineers dealing with durability problems, allowing the selection of fatigue strength curves at various failure probabilities depending on the sought safety level.
Article
Engineering, Mechanical
Li Sun, Xiao-Guang Bao, Su-Juan Guo, Run-Zi Wang, Xian-Cheng Zhang, Shan-Tung Tu
Summary: The cyclic behavior of a nickel-based GH4169 superalloy under fully-reversed and asymmetric creep-fatigue tests at 650°C was investigated. Significant tension-compression asymmetry and continuous cyclic softening were observed for all loading waveforms. The material exhibited mean stress relaxation under both asymmetric loading and fully-reversed loading, with the stress relaxation behavior during the dwell period being almost independent of the number of cycles.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Nanoscience & Nanotechnology
Michael L. Santella, Peter F. Tortorelli, Mark Render, Bruce Pint, Hong Wang, Vito Cedro, Xiang (Frank) Chen
Summary: The study used multiple data sets from a single laboratory to analyze the creep lifetime prediction of aged Haynes 282 alloy, showing the need to consider two different modes under different temperature and stress conditions for more accurate predictions. Additionally, the difference in grain size has an impact on the predictive ability of creep lifetime.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Multidisciplinary
Jafar Albinmousa, Muhammed J. Adinoyi, Nesar Merah
Summary: Stainless steels are known for their high corrosion resistance and strength, with AISI 410 specifically lacking research in multiaxial fatigue. Experimental results showed additional stress hardening and cyclic stress softening in the alloy under non-proportional loading, challenging existing fatigue damage models.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Crystallography
Zheng Fang, Lu Wang, Zheng Wang, Ying He
Summary: High-temperature fatigue tests were conducted to study the fatigue crack initiation behavior of ferrite-pearlite steel. Two approaches were developed and compared for modeling fatigue crack initiation under high temperatures in this study. The results indicate that both approaches can predict the location and life of fatigue crack initiation, but they have different computational costs and applicability.
Article
Engineering, Mechanical
Xiao-Cheng Zhang, Jian-Guo Gong, Fu-Hai Gao, Fu-Zhen Xuan
Summary: Improved creep-fatigue life prediction models based on time fraction (TF) and ductility exhaustion (DE) rule is established for components at elevated temperatures. The models incorporate cyclic softening/hardening and stress relaxation models, and validations show that they present more realistic evolution behavior of materials. The predicted life by the improved model differs from that by the half-life model depending on the cyclic behaviors of materials.
JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Materials Science, Multidisciplinary
Timothy Ngeru, Dzhem Kurtulan, Ahmet Karkar, Stefanie Hanke
Summary: This study aims to enhance the understanding of material behavior under complex load conditions by investigating the material reaction and crack formation under multiaxial stress states through fatigue tests. The experimental results reveal strain hardening under compressive strain and cyclic softening under torsional shear stresses. The cracks exhibit unusual characteristics with multiple branching and cracks perpendicular to the surface cracks on the sample's cross section.
Article
Engineering, Mechanical
Xiaowei Liao, Hanlin Wei, Liuyang Feng, Huiyong Ban
Summary: This paper investigates the low-cycle fatigue properties of a stainless-clad 304 + Q235B bimetallic steel plate and provides a comprehensive understanding of its cyclic response, failure mode, and fatigue strength. The experimental results show that the steel possesses excellent low-cycle fatigue resistance.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Atri Nath, Sudhirkumar Barai, Kalyan Kumar Ray
Summary: This study examines a methodology that combines Chaboche's CIKH model and genetic algorithm optimization technique to simulate the cyclic-plastic response of materials exhibiting cyclic hardening or softening behavior. The results demonstrate the accuracy of this approach in predicting the experimental results for various materials and its comparability with existing predictions, validating its applicability.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Casey Jessop, Johan Ahlstrom, Christer Persson, Yubin Zhang
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2020)
Article
Materials Science, Multidisciplinary
Nitesh Raj Jaladurgam, Hongjia Li, Joe Kelleher, Christer Persson, Axel Steuwer, Magnus Hornqvist Colliander
Article
Engineering, Mechanical
Rostyslav Skrypnyk, Uwe Ossberger, Bjoern A. Palsson, Magnus Ekh, Jens C. O. Nielsen
Summary: Railway crossings suffer from severe load environment leading to degradation of rail profiles due to high contact pressure and traction. Measurements were taken at a test site in Austria with accumulated traffic load of 65 MGT to validate simulation methods. Predicted rail profile degradation may exceed measured levels, possibly due to uncertainties in traffic distribution and differences in material properties.
Article
Nanoscience & Nanotechnology
Hongjia Li, Fredrik Larsson, Magnus Hornqvist Colliander, Magnus Ekh
Summary: Anisotropic 1-site and 2-site self-consistent models have been developed to describe the elastic-viscoplastic behavior of polycrystalline materials deformed to finite strains. The choice of rate-dependent constitutive law at single crystal level is discussed and verified through fitting experimental data. Both models have been validated by thoroughly fitting experimental data in literatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Carolyn Oddy, Magnus Ekh, Tomas Ekermann, Stefan Hallstrom, Martin Fagerstrom
Summary: The use of 3D-woven composite materials has shown promising results, but efficient computational models are needed for widespread adoption in industry. This study proposes a flexible framework for modeling the mechanical response of 3D-woven composites, demonstrating non-linear behaviors under different loading conditions and providing a method to predict material response effectively.
MECHANICS OF MATERIALS
(2021)
Article
Transportation Science & Technology
Ali Esmaeili, Johan Ahlstrom, Magnus Ekh, Dimitrios Nikas, Tore Vernersson
Summary: This paper focuses on material modeling of pearlitic steel for a wide range of loading rates at elevated temperatures, considering the thermal and rolling contact loading on block braked railway wheels. The viscoplasticity model including nonlinear isotropic and kinematic hardening, Delobelle overstress function, and static recovery of hardening have been calibrated using various experiments, highlighting the importance of accounting for viscoplasticity in modeling the material behavior.
RAILWAY ENGINEERING SCIENCE
(2021)
Article
Engineering, Mechanical
Nicola Zani, Magnus Ekh, Anders Ekberg, Angelo Mazzu
Summary: A semi-analytical model is introduced to assess rolling contact fatigue problems in railway applications, based on the Chaboche-Lemaitre constitutive law and implementation of the Dang Van multiaxial fatigue criterion. It is found that for the same Hertzian pressure, small-scale contact causes a deeper plasticized layer compared to elliptical full-scale contact.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Ali Esmaeili, Johan Ahlstrom, Bjorn Andersson, Magnus Ekh
Summary: This study examines the potential phase transformations in pearlitic rail and wheel steels due to short-term local friction heating events in railway operations. A modelling framework combining phase transformations with cyclic plasticity for individual phases has been proposed and calibrated against test data. Simulations demonstrate phase transformations and development of cyclic residual stresses in different phases under double heating events followed by rolling contact loadings.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
S. M. Mirkhalaf, M. Ekh, F. Larsson, M. Fagerstroem, T. J. H. van Beurden
Summary: A new micro-mechanical model is proposed to predict the non-linear elasto-plastic behavior of short fiber reinforced composites. The model is based on a two-step Orientation Averaging method and can accommodate a wide range of micro-structural parameters. Comparisons to experiments and numerical simulations show that the model provides accurate predictions. Additionally, the model is computationally efficient and can be used in applications with different fiber orientations.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Thermodynamics
Bjorn Andersson, Johan Ahlstrom, Magnus Ekh, B. Lennart Josefson
Summary: In this study, macroscopic modeling of phase transformations and mechanical behavior of low alloy steels is developed and investigated. This modeling is important for simulating transient thermo-mechanical processes in industries such as railways. Different homogenization methods along with phase transformation kinetics and individual constitutive models are utilized in the modeling approach. The importance of including transformation induced plasticity in the modeling as well as the multi-phase stages of heating and cooling are highlighted.
JOURNAL OF THERMAL STRESSES
(2022)
Article
Mechanics
Carolyn Oddy, Magnus Ekh, Martin Fagerstrom
Summary: There is a growing demand for lightweight materials with improved performance and reduced manufacturing costs in various industries. This study proposes a macroscopic model to predict the material response of a 3D glass fiber reinforced epoxy material system, capturing experimentally observed inelastic strains and stiffness reductions. The model is general, thermodynamically consistent, and allows for modular addition and calibration of various non-linear phenomena depending on loading direction.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Kim Louisa Auth, Jim Brouzoulis, Magnus Ekh
Summary: A fully coupled thermodynamically consistent chemo-mechanical modeling framework is proposed to explain the accelerated crack propagation of nickel-based superalloys in high temperatures and oxygen-rich environments. The model incorporates the reduction of grain boundary strength due to the presence of oxygen and the enhancement of oxygen diffusion under tensile mechanical loading. Experimental and numerical simulation results validate the effectiveness of the model.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Engineering, Civil
Kourosh Nasrollahi, Jens C. O. Nielsen, Emil Aggestam, Jelke Dijkstra, Magnus Ekh
Summary: This study presents a methodology for simulating long-term differential track settlement, voided sleeper development, and evolving irregularities in track geometry at the transition between two different track forms. An iterative approach is used to predict accumulated settlement based on a time-domain model of dynamic vehicle-track interaction. Gravity loads and state-dependent track conditions, including a prescribed variation of supporting foundation stiffness, are taken into account. A two-dimensional nonlinear finite element model of layered soil is also used to determine the support stiffness of each sleeper in the track model. The methodology is applied to a transition zone between a ballasted track and a slab track under heavy haul traffic, and the effects of higher axle loads and under sleeper pads on sleeper settlement are analyzed.
ENGINEERING STRUCTURES
(2023)
Article
Transportation Science & Technology
Rostyslav Skrypnyk, Bjorn A. Palsson, Jens C. O. Nielsen, Magnus Ekh
Summary: This study compares the long-term degradation of three fixed railway crossings with different crossing angles using simulation methodology, showing that damage increases with higher crossing angles. The ratio of maximum damage between the crossings with the largest and smallest angles is about three for wear and about two for plastic deformation.
INTERNATIONAL JOURNAL OF RAIL TRANSPORTATION
(2021)
Article
Materials Science, Multidisciplinary
Ceena Joseph, Mattias Thuvander, Christer Persson, Magnus Hornqvist Colliander
Summary: Research has shown that in Ni-base superalloys, air cooling after solution treatment and carbide stabilization can lead to precipitation of nm-sized gamma' particles, whereas precipitation is suppressed during water quenching. The solution treatment and carbide stabilization have significant effects on the subsequent gamma' precipitation during air cooling.
PHILOSOPHICAL MAGAZINE LETTERS
(2021)
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)
