International Journal of Fatigue最新文献

{"title":"Enhanced fatigue crack propagation resistance of Al-Cu-Li alloys via regulating grain structure and precipitation behavior","authors":"Guang-jun Zeng ,&nbsp;You-jie Guo ,&nbsp;Chen-chen Xiong ,&nbsp;Hao-ran Li ,&nbsp;Wei Zhou ,&nbsp;Hui Xiang ,&nbsp;Peng-cheng Ma ,&nbsp;Yong-lai Chen ,&nbsp;Jin-feng Li ,&nbsp;Dan-yang Liu","doi":"10.1016/j.ijfatigue.2025.108916","DOIUrl":"10.1016/j.ijfatigue.2025.108916","url":null,"abstract":"<div><div>The fatigue crack propagation (FCP) resistance of Al-Cu-Li alloys was improved via regulating grain structure and precipitation behavior, and their effect on the FCP rate was further elucidated. It was revealed that modifying the solution heating rate significantly affected the grain structure and FCP behavior. Specifically, the decreased solution heating rate resulted in an alternative distribution of recrystallized grains and sub-grain bands, with a larger recrystallized-grain size and increased sub-grain band density. This microstructural evolution altered the reversible plastic zone (<em>Rp</em>) scale at the crack tip, where the <em>R_p/D</em> ratio (D: recrystallized-grain size) in samples with 2 °C/min solution heating rate (2HR) ranged from 0.31 to 1.22, leading to transgranular crack propagation and decreased FCP rates. Furthermore, the sub-grain zones in 2HR sample exhibited low tilt and twist angle differences and featured shearable T₁ precipitates, promoting crack deviation and bifurcation. In contrast, the specimens subjected to direct solution treatment (DST) showed a by-passing mechanism during T₁ precipitates-dislocation interaction. The shearable T₁ precipitates contributed to strain energy release, while the by-passed T₁ precipitates facilitated intergranular crack propagation. Thus, the FCP resistance of 2HR sample was significantly enhanced compared to DST sample. These findings provided a novel approach to improving the FCP resistance of Al-Cu-Li alloy through controlled microstructural design.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108916"},"PeriodicalIF":5.7,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143583090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and theoretical investigations of macro fiber composite actuation degradation induced by the mechanical load","authors":"Jiaxuan Zhang ,&nbsp;Wen Cai ,&nbsp;Bin Li ,&nbsp;Liyuan Li ,&nbsp;Wenchao Niu","doi":"10.1016/j.ijfatigue.2025.108911","DOIUrl":"10.1016/j.ijfatigue.2025.108911","url":null,"abstract":"<div><div>Macro Fiber Composite (MFC) demonstrates promising application in morphing structure actuation and structural vibration active control. MFC patches are subject to mechanical loads in conjunction with the structure, which may result in actuation performance degradation. The actuation may not proceed as intended after the degradation. However, the actuation degradation of MFC under mechanical loading has been rarely addressed. In this study, the actuation degradation of MFC under mechanical loads respectively at room and higher temperatures is first investigated by experiments. The experimental results indicate that the mechanical-induced MFC actuation degradation exhibits a nonlinear trend, and compressive loads show a trivial impact on the actuation degradation. Mechanical-induced actuation degradation becomes more significant with the increase of the tensile load and temperature. Further, a finite element model based on a damage evolution model is proposed for the sake of time and economic cost. The predictions align well with the experimental data. The experimental evidence and theoretical predictions show that the mechanical-induced actuation degradation arises from the MFC stiffness degradation and irreversible degradation of piezoelectric properties. The finite element model further verifies that the microcracks accumulation before the creation of the visible cracks contributes to the great initial degradation.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108911"},"PeriodicalIF":5.7,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D damage evolution and microstructural-based machine learning model for stiffness prediction in woven composite under cyclic loads","authors":"Mritunjay M. Hiremath ,&nbsp;Nikhar Doshi ,&nbsp;Timo Bernthaler ,&nbsp;Pascal Anger ,&nbsp;Sushil K. Mishra ,&nbsp;Anirban Guha ,&nbsp;Asim Tewari","doi":"10.1016/j.ijfatigue.2025.108913","DOIUrl":"10.1016/j.ijfatigue.2025.108913","url":null,"abstract":"<div><div>Tension-compression cyclic loading poses significant challenges due to its severe impact on the stiffness degradation of composites, making accurate predictions of microstructural damage essential for structural reliability. In this study, microstructural damage in woven composites is analysed using X-ray microscopy under equal and critical stress ratio conditions of tension–compression cyclic loading. Quantified damage data are used to train machine learning models, including support vector regression (SVR), random forest (RF) and neural network (NN). Experimental results revealed that under both stress ratios, perpendicular cracks initiated first, followed by cracks at the weft/warp interface. The degradation in the stiffness was approximately 22.46 % under the equal stress ratio condition and 17.62 % under critical stress ratio condition after 100,000 cycles<em>.</em> Machine learning models demonstrated robust performance, with SVR (average error rate = 0.15 %) and RF (average error rate = 0.13 %) closely aligning with experimental data when trained and tested on their respective stress ratios. Notably, flipped dataset analysis revealed that RF (average error rate = 1.02 %) and NN (average error rate = 1.05 %) models trained on equal stress ratio data effectively predicted critical stress ratio behaviour, showcasing their adaptability. These findings highlight the potential of machine learning-driven approaches for predictive modelling, enabling more efficient material design and optimization under cyclic loading conditions.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108913"},"PeriodicalIF":5.7,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure and bending fatigue behavior of martensite steel with 0.4%C subjected to different heat treatments","authors":"Jiaqiang Dang,&nbsp;Ryuji Yabutani,&nbsp;Sien Liu,&nbsp;Shoichi Nambu","doi":"10.1016/j.ijfatigue.2025.108910","DOIUrl":"10.1016/j.ijfatigue.2025.108910","url":null,"abstract":"<div><div>The purpose of the present work was to analyze the microstructure evolution of martensite steel with 0.4C (in mass%) under different heat treatments which were marked as OQ900 and OQ1000, and its effect on fatigue fracture behavior. A crystal plasticity finite element method (CPFEM) was developed to analyze the role of multi-scale structures of lath martensite on fatigue crack initiation, and the fatigue lives of the materials with varying substructures are quantitatively compared. The numerical simulation was verified by fatigue tests where special attention was paid on the peculiarity of crack initiation exposed to the microstructural effect. The fracture surfaces of the steels subjected to both high-cycle fatigue (HCF) and low-cycle fatigue (LCF) regimes were also analyzed. The results indicated that OQ900 sample hold a smaller size in equivalent prior austenite grain, packet and block length than OQ1000 sample, which finally led to a slightly higher bending strength for OQ900 sample. Both inclusions and slipping fractures were found as the origins of fatigue crack initiation in the martensite steels with 0.4C, and especially the latter played a dominant role in HCF regime. In this regard, the difference in fatigue life tended clear as a clue to the effect of microstructure on fatigue behavior in HCF regime. The block morphology and its orientation affected the strain localization in an obvious way, where lower fracture indicator parameters (FIPs) value and longer crack initiation life were obtained in OQ900 sample. The EBSD analysis of fatigue-tested samples showed that the block boundaries were the most preferred sites for crack initiation, which were characterized as persistent slip bands. The crack propagation path was distributed in a deflected manner owing to the inhibition effect of boundaries. Overall, OQ900 sample presents a higher fatigue resistance than OQ1000 in HCF regime when the initiation and early propagation life of fatigue cracks were considered.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108910"},"PeriodicalIF":5.7,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new low-cycle and high-cycle fatigue life prediction criterion based on crystal plasticity finite element method","authors":"Jinshan He ,&nbsp;Chunfeng Hu ,&nbsp;Runze Zhang ,&nbsp;Pinpin Hu ,&nbsp;Chengbo Xiao ,&nbsp;Xitao Wang","doi":"10.1016/j.ijfatigue.2025.108903","DOIUrl":"10.1016/j.ijfatigue.2025.108903","url":null,"abstract":"<div><div>The present study proposes a novel physically-based criterion for simultaneously predicting both high-cycle and low-cycle fatigue life by incorporating slip irreversibility. Considering the damage induced by irreversible plastic deformation on the foundation of cumulative dissipation energy, this criterion serves as an effective tool for assessing fatigue life. Based on the construction of multiple RVE models combined with crystal plastic finite element method, we successfully predicted the high- and low-cycle fatigue life of micro-grain K4169 alloy within a scatter band of ± 1.5 by this new fatigue parameter indicator. Notably, the prediction error of high-cycle fatigue life is within 10 %, a 70 % reduction compared to the cumulative dissipated energy criterion. On such basis, the slip irreversible coefficients (<em>p</em>) at different loading conditions were predicated precisely and validated by experimental data obtained from atom force microscope. Then a double logarithmic linear relationship between <em>p</em> and fatigue life of the alloy was established with the equation <span><math><mrow><mi>p</mi><mo>=</mo><mn>1.2</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>-</mo><mn>3</mn></mrow></msup><mo>∙</mo><msubsup><mi>N</mi><mrow><mi>f</mi></mrow><mrow><mo>-</mo><mn>0.4079</mn></mrow></msubsup></mrow></math></span>. In addition, the high-cycle fatigue life of fine-grain K4169 alloy was also precisely predicted within a scatter band of ± 2.5 by adjusting grain size in RVE models.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108903"},"PeriodicalIF":5.7,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface fatigue in lubricated contacts: Mapping the failure modes of micropitting versus macropitting","authors":"B. Wainwright,&nbsp;A. Kadiric","doi":"10.1016/j.ijfatigue.2025.108908","DOIUrl":"10.1016/j.ijfatigue.2025.108908","url":null,"abstract":"<div><div>This paper presents a surface-fatigue failure mode map to identify contact conditions which preferentially lead to (i) micropitting, (ii) initial micropitting transitioning to surface-initiated macropitting, and (iii) surface-initiated macropitting failure modes in lubricated rolling-sliding contacts representative of rolling bearings and gears. The study used a triple disc fatigue rig to systematically investigate the effect of contact pressure, surface roughness and Λ-ratio on the type of surface fatigue damage mode. Specimens made of case-carburised 16MnCr5 steel and a custom-blended PAO + ZDDP oil were used. Results show that higher Hertz contact pressures strongly favour the occurrence of macropitting over micropitting; In present tests no macropitting was detected in any tests at Hertz pressures less than 1.5 GPa. Conversely, lower pressures favour micropitting. This is likely due to higher macro-pressure being able to drive the surface-initiated cracks deeper into the subsurface material, which was shown to be a pre-requisite for formation of macropits. Higher roughness favours micropitting due to higher asperity stresses, while the influence of Λ-ratio on the type of failure mode is relatively weak as long as contact is within mixed/boundary lubrication regime. Higher roughness and lower Λ increased the severity of micropitting. Micropitting incubation time was between 100,000 and 1 million cycles depending on contact conditions, it is shorter for higher R_q  and/or lower Λ. Transition of initial micropitting to a more damaging macropitting mode is promoted by higher Hertz pressures but impeded by more severe rates of micropitting wear which occur at higher roughnesses and lower Λ-ratios. Given the different implications of micropitting versus macropitting, the presented failure mode map can be used during the design process to help improve the reliability of machines.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108908"},"PeriodicalIF":5.7,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potentials and limitations of direct current potential drop for measuring elliptical cracks in round bars","authors":"Luca Vecchiato ,&nbsp;Alberto Campagnolo ,&nbsp;Matteo Cova ,&nbsp;Giovanni Meneghetti","doi":"10.1016/j.ijfatigue.2025.108904","DOIUrl":"10.1016/j.ijfatigue.2025.108904","url":null,"abstract":"<div><div>This study investigates potentials and limitations of the Direct Current Potential Drop (DCPD) method for monitoring fatigue crack size in single-edge-crack round bars made of 42CrMo4 steel. Specimens with a semi-elliptical crack-starter notch were tested under axial fatigue loading, with DCPD applied in various configurations to evaluate the impact of current and potential probe positions on measurement overall accuracy. Therefore, experimental DCPD calibration data were developed by correlating the measured signals with the corresponding crack fronts identified through beach marking. Eventually, experimental data were compared with calibration curves obtained from electrical FE analyses, where semi-elliptical cracks were modelled using crack fronts best fitted to the beach-marked experimental fronts. The results confirmed the reliability and accuracy of DCPD for monitoring fatigue crack growth in single-edge-crack round bars, provided that the propagating crack shape is known a priori. Moreover, the effect of probe positioning was highlighted: current injection near the crack plane with potential probes at the crack symmetry plane improved measurability, while the highest sensitivity was achieved with probes near the crack tip. Both local and remote current injections, with current and potential probes at the crack symmetry plane, provided comparable accuracy, making these setups promising for experimental fracture mechanics testing.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108904"},"PeriodicalIF":5.7,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy-based multi-axial fatigue prediction for tubular structures under non-proportional loading","authors":"Jiashan Gao ,&nbsp;Shaoping Wang ,&nbsp;Chao Zhang ,&nbsp;Rentong Chen ,&nbsp;Yunhao Zhang ,&nbsp;Yuwei Zhang ,&nbsp;Rui Mu","doi":"10.1016/j.ijfatigue.2025.108897","DOIUrl":"10.1016/j.ijfatigue.2025.108897","url":null,"abstract":"<div><div>The tubular structure suffers from structural complexity, and it is also subjected to multi-axial loading, which makes the prediction of its fatigue life difficult. This study proposes a multi-axial fatigue life prediction model for tubular structures based on the energy method for non-proportional loading (MFLPM-ENPL). An energy-based method, considering the impact of residual stresses in welded joints, is first proposed. This model accurately captures the complexities of fatigue behavior by calculating the elastic strain energy of the tubular structure and the plastic strain energy at the welded part. To solve the problem of equivalent loading in the context of non-proportional load paths, a novel equivalent non-proportional factor is then designed. Tailored to the stress characteristics of tubular structures, it facilitates accurate load-equivalence conversion. Finally, by combining the designed non-proportional factor with the energy-based multi-axial fatigue life prediction method for tubular structures, a multi-axial fatigue life prediction model for tubular structures based on the energy method for non-proportional loading is developed. Through validation with diverse multi-axial test datasets—including various node types, material grades (e.g., C45 steel, Al6082-T6), and loading conditions—the proposed model achieves 93.6% accuracy within a 1.5<span><math><mo>×</mo></math></span> scatter band, surpassing existing methods in both predictive precision and robustness. Furthermore, its extensible design accommodates the incorporation of variable-amplitude loading scenarios and advanced damage-accumulation models, underscoring its potential to improve structural reliability across a broad spectrum of engineering domains.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108897"},"PeriodicalIF":5.7,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue life prediction and optimization of two-stage stiffness leaf spring with ANN","authors":"Weihuan Chen ,&nbsp;Junhui Zhao","doi":"10.1016/j.ijfatigue.2025.108899","DOIUrl":"10.1016/j.ijfatigue.2025.108899","url":null,"abstract":"<div><div>Fatigue life prediction of leaf springs is critical during the vehicle design stage. Fatigue life calculation based on linear superposition cannot guarantee accuracy, while fatigue life calculation based on direct transient analysis is extremely time-consuming. This paper aims to assess the fatigue life of two-stage stiffness leaf springs under random road loads with high accuracy and efficiency. The key to predicting the fatigue life of two-stage stiffness leaf springs is to calculate the full-field stress-time history based on artificial neural networks (ANN) and finite element analysis (FEA). Road loads were measured using a road test, and multi-body simulation (MBS) was performed to calculate the leaf spring force-time history. Statistical analysis was conducted on the force-time history to generate input for FEA to acquire ANN training data. The ANN was built and trained to calculate the leaf spring stress-time history using the leaf spring force-time history as input. Fatigue life calculations were performed using the stress-time history. The results show that the calculation efficiency of the stress-time history based on ANN is improved by orders of magnitude compared to transient dynamics analysis. Meanwhile, the calculated fatigue life correlates well with the test results, and different loads have different contributions to fatigue damage.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108899"},"PeriodicalIF":5.7,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel notch classification model for stress gradient-based fatigue life prediction under low and high cycle fatigue loading","authors":"Jiayuan Gu ,&nbsp;Rui Zhang ,&nbsp;Xiaowei Wang ,&nbsp;Heng Li ,&nbsp;He Zhu ,&nbsp;Xiancheng Zhang ,&nbsp;Jianming Gong ,&nbsp;Shantung Tu","doi":"10.1016/j.ijfatigue.2025.108907","DOIUrl":"10.1016/j.ijfatigue.2025.108907","url":null,"abstract":"<div><div>In this work, a novel notch classification approach that considers the notch effects is developed. The classification of notches is implemented based on the stress gradient along the most critical path, defining the stress field diameter that quantifies the localized fatigue damage of the component. Then, a modified field intensity fatigue life prediction model using the developed notch classification is proposed. To evaluate the prediction capability of the proposed method, life predictions for various notch types of Inconel 718, Stainless steel 304 and 316H are carried out. For high temperature low cycle fatigue tests, the proposed model keeps the prediction accuracy of notched components falling within the scatter band of 2 times. Furthermore, the model also demonstrates satisfactory life prediction capabilities for high cycle fatigue. Finally, a scheme for predicting S-N curves of notched specimen is presented and validated.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"197 ","pages":"Article 108907"},"PeriodicalIF":5.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}