Article
Engineering, Mechanical
Z. M. Jian, G. A. Qian, D. S. Paolino, A. Tridello, F. Berto, Y. S. Hong
Summary: The study revealed that AlSi10Mg specimens printed with 50μm powder size exhibit higher fatigue properties compared to those printed with 20μm powder size, with unmelted powders being the main source of crack initiation. Additionally, specimens printed with 50μm powder size are more prone to subsurface crack initiation in the VHCF regime, with five different crack initiation modes identified and fatigue strength assessed by statistical model.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Materials Science, Multidisciplinary
Fulin Liu, Yao Chen, Lang Li, Chong Wang, Qingyuan Wang, Yongjie Liu
Summary: The interior defect-induced crack initiation mechanism and early growth behavior of Ti6Al4V alloy fabricated by laser powder bed fusion (LPBF) have been investigated in the very high cycle fatigue (VHCF) regime. The findings show that the formation of fine granular area (FGA) is composed of discontinuous nanograins, which are associated with dislocation movement and grain boundaries. Additionally, the fatigue loading process and the LPBF process contribute to the development of microvoids, accelerating the extension of microcracks.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Mechanical
Tobias Daniel, Marek Smaga, Tilmann Beck
Summary: This study investigated the cyclic deformation behavior of metastable austenitic stainless steels in the very high cycle fatigue regime using ultrasonic fatigue testing. The results showed cyclic softening in the high cycle fatigue regime and cyclic hardening in the very high cycle fatigue regime, leading to the determination of the true endurance limit for the material.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Jiebin Shen, Haidong Fan, Jian Wang, Guoqian Zhang, Rong Pan, Zhiyong Huang
Summary: The fatigue crack initiation at twin boundary (TB) and the life prediction of IN718 alloys in the high cycle fatigue (HCF) regime and very high cycle fatigue (VHCF) regime were investigated. A fatigue damage parameter, Gba, was proposed to precisely characterize the plastic strain distribution and localization, which was used to locate fatigue crack initiation site and predict the fatigue life. The results showed the coupling of slip activation parallel to the TB and the absence of primarily strengthening phase (gamma) on the both side near the TB were responsible for crack initiation.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Aman Arora, Aanchna Sharma, Mohit Singh, Dhiraj K. Mahajan, Vinod Kushvaha
Summary: This study presents an extensive experiment on the fatigue response of glass-filled epoxy composites under cyclic loading. Rod-shaped particulate glass fibers with volume fractions of 0%, 5%, 10%, and 15% are used to reinforce the epoxy matrix. The mechanical behavior of the resulting composite is examined under monotonic tensile loading and tension-tension cyclic fatigue loading. The study utilizes in-situ low cycle fatigue testing to investigate the damage mechanisms leading to crack initiation and propagation.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Nanoscience & Nanotechnology
Fulin Liu, Yao Chen, Chao He, Yongjie Liu, Chong Wang, Qingyuan Wang, Lang Li
Summary: This study investigates the failure mechanism of bimodal titanium alloy under very high cycle fatigue conditions. Circular creep-fatigue voids (CFVs) and sub-grain boundaries (GBs) were found to play a role in crack initiation and early propagation. A new mechanism was proposed based on these findings.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Carsten Wickmann, Christopher Benz, Horst Heyer, Kerstin Witte-Bodnar, Jan Schaefer, Manuela Sander
Summary: This study aimed to investigate the formation of the 'fine granular area' (FGA) in additively manufactured Ti6Al4V specimens with artificially generated internal defects in the early stage of fatigue crack growth in the 'very high cycle fatigue' (VHCF) regime. Fatigue tests were conducted using an ultrasonic fatigue testing setup, and failed specimens were analyzed using optical microscopy, scanning electron microscopy (SEM), and focused ion beam (FIB) techniques. Alternative proposals for identifying the FGA layer were introduced, and various fracture mechanical approaches were applied to evaluate the possibility of FGA formation, with results compared to experimental findings.
Article
Materials Science, Multidisciplinary
Xiangnan Pan, Leiming Du, Guian Qian, Youshi Hong
Summary: This study investigates the behavior of very-high-cycle fatigue (VHCF) in metallic materials such as aluminum alloys and high-strength steels. The research reveals that in additively manufactured AlSi10Mg alloy, crack initiation and growth mechanisms are distinct from those in high-strength steels, but demonstrate a similar characteristic region of crack initiation known as fine granular area (FGA).
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2024)
Article
Engineering, Mechanical
Tim Schopf, Stefan Weihe, Tobias Daniel, Marek Smaga, Tilmann Beck
Summary: The VHCF regime of austenitic steels used in nuclear power plants has not been well characterized. Fatigue tests were performed on the metastable austenitic steel AISI 347/1.4550 at high test frequencies. An elastically plastic assessment method produced good results, while a purely elastic assessment commonly used in literature was not conservative. In the VHCF regime, phase transformation and no specimen failure occurred, indicating the existence of an endurance limit for this material.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
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
R. Branco, P. A. Prates, J. D. Costa, J. A. Martins Ferreira, C. Capela, F. Berto
Summary: This study examines the notch fatigue behavior and crack initiation life estimation in maraging steel fabricated by laser beam powder bed fusion under multiaxial loading through experiments and numerical simulations. The results show that both simulation methods accurately predict the crack initiation sites, directions of crack growth, and fatigue life, with elastic-plastic predictions leading to smaller errors but slightly shifting to the non-conservative side.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Biochemistry & Molecular Biology
Jun-ichi Horinaka, Soma Ogawa
Summary: The effects of gelation concentration (c0) on the cyclic deformation behavior of agarose hydrogels were investigated. Agarose hydrogels prepared at c0 = 10 g L-1 (A10) exhibited smaller Young's modulus than those prepared at c0 = 30 g L-1 (A30), even when the agarose concentration was the same at 50 g L-1. Additionally, A10 showed a stronger tendency to exhibit residual strain in cyclic deformation curves compared to A30. These findings can be explained by the gelation mechanism specific to agarose, where agarose helices aggregate via hydrogen bonding to form crosslinks. It was observed that the helix content just after gelation increased with c0, while the helix content for A10 was higher than that for A30 at 50 g L-1. The cyclic deformation behavior and Young's modulus of agarose hydrogels primarily reflect the network structure determined by c0, as lower helix content at c0 for A10 resulted in less stable agarose helix aggregates.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Materials Science, Multidisciplinary
Lin Li, Jie Yang, Zhiyuan Yang, Qi Sun, Li Tan, Qinghui Zeng, Minhao Zhu
Summary: Deformation twins play a crucial role in plastic deformation and affect the microstructural evolution and fatigue behavior of magnesium alloys. The study investigated the fatigue behavior of a rolled magnesium alloy using SEM and EBSD, revealing that {1012} twinning dominates the fatigue deformation process and residual twins increase with fatigue cycles. Cracks tend to initiate and propagate along {1012} twinning boundaries and slip bands, with numerous extrusions found in twinned areas.
MATERIALS CHARACTERIZATION
(2021)
Article
Engineering, Geological
Hasan Ali Abbas, Zainab Mohamed, Sakhiah Abdul Kudus
Summary: This research studied the strength and progressive damage of weathered (sandstone-shale-sandstone) composite samples using acoustic emission (AE) and ultrasonic pulses. The presence of shale significantly impacted the behavior of the composite. The deformation behavior was derived from the responses of both ultrasonic and AE waves. The research helps evaluate the deformation behavior of interbedded rock masses using the ultrasonic approach.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Zhongwei Xu, An Liu, Xishu Wang
Summary: This study investigates the performance differences between rolled and selective laser melted (SLM) Ti6Al4V alloys commonly used for orthopedic implants. The results show that the fatigue performance of SLM Ti6Al4V alloy is influenced by the building direction, with certain directions exhibiting excellent crack propagation resistance. Based on these findings, it can be expected that SLM components in different building directions will have varying fatigue performances.
MATERIALS CHARACTERIZATION
(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)