International Journal of Fatigue最新文献

{"title":"Fatigue and fracture characterisation of copper-brazed 316L stainless steel","authors":"Tonica Bončina,&nbsp;Franc Zupanič,&nbsp;Branko Nečemer,&nbsp;Roman Satošek,&nbsp;Erik Rihter,&nbsp;Srečko Glodež","doi":"10.1016/j.ijfatigue.2025.109333","DOIUrl":"10.1016/j.ijfatigue.2025.109333","url":null,"abstract":"<div><div>This study focuses on the mechanical, fatigue and metallographic characterisation of copper-brazed 316L stainless steel for the potential use in different plate heat exchangers (PHE) applications. The quasi-static and fatigue tests have been performed on the specially designed copper-brazed tensile specimens to obtain the engineering stress–strain diagram and the fatigue life curve of the analysed brazed joint. Furthermore, a comprehensive metallographic investigation has been done, focusing on (i) material characterisation of as-received stainless steel 316L, (ii) characterisation of the brazed joint and (iii) fractographic analyses of fractured surfaces by quasi-static and fatigue loading. The obtained experimental results may be beneficial for designing copper-brazed plate heat exchangers in the future.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109333"},"PeriodicalIF":6.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321242","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":"Probabilistic fatigue life prediction for welded joints with undercuts considering crack initiation variability and multi-crack interaction","authors":"Yan Ma ,&nbsp;Chuang Cui ,&nbsp;Yong Xia ,&nbsp;Qinghua Zhang ,&nbsp;Kun Tang","doi":"10.1016/j.ijfatigue.2025.109332","DOIUrl":"10.1016/j.ijfatigue.2025.109332","url":null,"abstract":"<div><div>Weld-toe undercuts, as common welding imperfections, generate severe localized stress concentrations along the weld toe. The resulting stochastic crack initiation and subsequent multi-crack interactions markedly degrade the fatigue resistance of welded joints. Conventional deterministic methods fail to adequately address these uncertainties, limiting their applicability in safety–critical assessments. This study proposes a probabilistic prediction framework integrating a fracture mechanics-based crack growth model, fatigue testing, and Monte Carlo simulation to predict the fatigue life of welded joints with undercuts. The model explicitly accounts for weld-toe amplification, notch effects, multi-crack interaction, and crack closure to quantify the crack driving force at weld-toe undercut tips, and to accurately simulates these multiple cracks interaction, coalescence, and propagation. Fatigue tests on cruciform-welded (CW) and butt-welded (BW) Q420qFNH steel joints validate this model and provide statistical inputs for simulations. Monte-Carlo simulations then yield reliability-based fatigue life by accounting for the variability of crack initiation at weld-toe notches. Results demonstrate that fatigue strength is predominantly controlled by undercut depth (secondary by curvature radius), with maximum allowable depths of 0.7 mm and 0.5 mm for CW and BW joints to comply with IIW requirements at 95 % reliability. The framework advances defect-tolerance design through reliability-based acceptance criteria, offering a practical tool for welding quality control.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109332"},"PeriodicalIF":6.8,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321241","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":"Study on electrothermal driving performance and cyclic stability of Ti45Ni55 shape memory alloy springs","authors":"Liwei Chen ,&nbsp;Pei Yu ,&nbsp;Xiangbo Zu ,&nbsp;Mingjiang Jin ,&nbsp;Wei Li ,&nbsp;Ke Zhang","doi":"10.1016/j.ijfatigue.2025.109334","DOIUrl":"10.1016/j.ijfatigue.2025.109334","url":null,"abstract":"<div><div>As a significant branch of NiTi shape memory alloys (SMAs), Ni-rich NiTi alloys have garnered considerable research attention. This study employs Ti₄₅Ni₅₅ (at.%) alloy wires to prepare dual-way SMA springs under various annealing temperatures via deformation-aging constraint methods, focusing on optimizing their phase transformation behavior, cyclic stability, and electrothermal driving performance under thermo-mechanical coupling. The results indicate that the phase transformation sequence of the alloy wire evolves with annealing temperature (400–550 °C), progressing from B2 → R to B2 ↔ R ↔ B19′ and ultimately to B2 ↔ B19′ transition, accompanied by generally decreasing phase transformation temperatures. Optimal superelasticity (residual strain &lt; 0.2 %) with distinct stress plateaus is achieved at 400–450 °C, while higher annealing temperatures reduce platform stresses but increase residual strain. The SMA spring annealed at 500 °C demonstrates superior actuation performance under thermomechanical coupling (3 N-1.5A), achieving maximum actuation displacement (73.9 ± 5.1 mm), fastest response (1.12 ± 0.2 s), and excellent fatigue resistance. Thermal hysteresis expansion correlates with increased A_f* and decreased R_f*. The minimal lattice distortion of R phase enables low-energy, high-speed actuation with enhanced cyclic stability. Functional degradation arises from residual stress, dislocation accumulation and concurrent nanocrystalline coarsening, which collectively destabilize the shape memory effect and martensitic transformation. These findings provide critical insights for designing high-performance SMA actuators through microstructure optimization.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109334"},"PeriodicalIF":6.8,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321243","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":"Analyzing the J-integral of bonded joints under fatigue loading conditions by determining beam rotations with edge detection","authors":"Gabriel Riedl ,&nbsp;Gernot M. Wallner","doi":"10.1016/j.ijfatigue.2025.109330","DOIUrl":"10.1016/j.ijfatigue.2025.109330","url":null,"abstract":"<div><div>This study presents an edge detection method for analyzing load point rotations and evaluating the J-integral in fatigue-loaded double cantilever beam (DCB) specimens. Images of backlit DCB specimens were captured at maximum load point displacement during fatigue tests. Load point rotation was assessed using an image processing algorithm. The analysis involved binarization, alignment, and edge detection. To validate the approach, J-integral values from image-based analysis were compared with linear elastic fracture mechanics (LEFM) methods, including compliance calibration and elastic foundation models. Three laminate systems, incorporating soft (ethylene vinyl acetate copolymer, EVA), structural (acrylic, DP8810), and brittle (acrylic, Kisling 2206) adhesives were tested under constant amplitude or constant strain energy release rate (SERR) fatigue loading at temperatures ranging from 23 to 80°C.</div><div>Glass/EVA laminates with a soft adhesive showed no significant difference between J-integral and LEFM methods under displacement control. However, under SERR control, J-integral values were up to 20 % lower at a constant SERR of 75 J/m² and 80 °C. Fractographic analysis revealed predominantly interfacial failure under displacement control and cohesive failure under SERR control. Aluminum/DP8810 laminates bonded with a structural acrylic adhesive exhibited no significant deviations between J-integral and LEFM results under both, displacement- and SERR-control. Failure was cohesive under both loading conditions. Similar behavior was observed for brittle electrical steel/acrylic laminates. No deviations were discernible under displacement control.</div><div>The edge detection-based approach enabled accurate, efficient J-integral determination without compliance calibration or material parameters, reducing error sources and broadening applicability to cases involving large damage zones and elastic–plastic adhesive behavior.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109330"},"PeriodicalIF":6.8,"publicationDate":"2025-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321274","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":"Multiscale characterization of white etching cracks and its adjacent white etching areas in M50 bearing steel","authors":"Yahui Deng ,&nbsp;Huan Teng ,&nbsp;Xinyu Jin ,&nbsp;Yangxin Wang ,&nbsp;Chundong Hu ,&nbsp;Han Dong","doi":"10.1016/j.ijfatigue.2025.109329","DOIUrl":"10.1016/j.ijfatigue.2025.109329","url":null,"abstract":"<div><div>Premature failure of bearings under rolling contact fatigue (RCF) is often associated with the formation of white etching cracks (WECs) and its adjacent white etching areas (WEAs). The formation mechanisms of WEC/WEAs in M50 bearing steel remain highly debated. To investigate the initiation and propagation of WEC/WEAs, two types of cracks and the branching were observed. A multiscale characterization of microstructural alterations was performed, focusing on carbide dissolution, elemental redistribution, and the role of hydrogen (H) in the formation of WEC/WEAs. The results show that WEC/WEAs exhibit a markedly lower carbon content and significantly enhanced hardness as compared to the matrix. Meanwhile, atom probe tomography (APT) and high-resolution transmission electron microscopy (HRTEM) reveal the presence of dissolved carbides or newly formed clusters within WEC/WEAs, accompanied by hydrogen segregation. These findings indicate that under prolonged RCF, severe plastic deformation induces the proliferation of dislocations and hydrogen segregation around carbides. This may accelerate carbide dissolution, along with microscopic elemental depletion and diffusion. Subsequently, carbide dissolution leads to localized hardness elevation and microstructural refinement, resulting in the formation of nanocrystalline and amorphous phases. This microstructural evolution promotes crack initiation and propagation, thereby accelerating the formation of WEC/WEAs.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109329"},"PeriodicalIF":6.8,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320839","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":"Crystallographic nature of cell boundaries developed during cyclic deformation of a near-1¯11-oriented copper single crystal","authors":"Tianchang Ma ,&nbsp;Leon Shimmi ,&nbsp;Yuyang Bai ,&nbsp;Tomotaka Miyazawa ,&nbsp;Sukyoung Hwang ,&nbsp;Shigeo Arai ,&nbsp;Toshiyuki Fujii","doi":"10.1016/j.ijfatigue.2025.109328","DOIUrl":"10.1016/j.ijfatigue.2025.109328","url":null,"abstract":"<div><div>Given the strong correlation between fatigue crack initiation and dislocation cell structures, elucidating the crystallographic nature of cell boundaries is fundamental to understanding fatigue mechanisms. In this study, three-dimensional electron backscatter diffraction combined with focused ion beam slicing was employed to characterize the formation planes of cell boundaries in a fatigued copper single crystal oriented near the <span><math><mrow><mfenced><mrow><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mtext>11</mtext></mrow></mfenced></mrow></math></span> direction. Beyond the (111) boundaries representative of mature cell structures, (110), (011), and (121) boundaries were identified as geometrically necessary segments initiated by cross-slip, which forms at the early stage of cell structures. The (110) and (011) boundaries include dislocation networks formed by Shockley partials dissociated from the perfect dislocations on different potentially activated slip planes. Subsequently, the (121) boundaries emerge after the cross-slip of screw dislocations and pile-up on the cross-slip plane. Cell bands preferentially form along the (121) plane because of the symmetrically arranged alternating {110} boundaries. The rotation axis between adjacent cells exhibits a strong dependence on misorientation angle, and the rotation axes are scattered around the [111] and [121] directions when the misorientation is small (&lt;1.0°). The [121] axis originates from the vector sum of [110] and [011], which corresponds to twist boundaries on the (110) and (011) planes. The (111) twist boundaries form and gradually replace the other geometrically necessary boundaries with an increase in the misorientation to accommodate increasing plastic incompatibility. This study uncovers the crystallographic nature of fatigue-induced cell structures and offers insights into enhancing metal performance through dislocation control.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109328"},"PeriodicalIF":6.8,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321244","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":"Study on the competitive mechanisms of pre-tension strengthening and fatigue damage in AZ31B magnesium alloy","authors":"Yulu Wang ,&nbsp;Shubang Wang ,&nbsp;Xiuli He ,&nbsp;Tingting Zhang ,&nbsp;Zhifeng Yan","doi":"10.1016/j.ijfatigue.2025.109326","DOIUrl":"10.1016/j.ijfatigue.2025.109326","url":null,"abstract":"<div><div>The fatigue strengthening effect of AZ31B magnesium alloy under different degrees of pre-tension deformation was studied. A detailed discussion is presented on the influence of strain on the relationship between fatigue strengthening and damage, from the macroscopic deformation to the microstructural level. The results show that the cross-sectional fatigue strength of the specimen at room temperature first increases and then decreases with the increase of pre-stretch deformation, which is inconsistent with the continuous downward trend of fatigue temperature increase. The 5% pre-tension deformation results in superior fatigue strength for the specimens, with a significant enhancement of 27.77%. The SEM morphology after tensile deformation and fatigue fracture reflects an increase in micro-defects and fatigue damage with the greater pre-tension deformation. Combining in-situ tensile EBSD results on strain hardening and grain orientation differences, the study ultimately analyzed the dialectical relationship between the microstructure and residual stress changes caused by pre-stretching deformation, and the fatigue strengthening and weakening of the specimens, from multiple perspectives. It aims to provide a scientific basis for optimizing the performance of this alloy in practical applications and lay a foundation for further understanding the complexity of its fatigue damage and fracture behavior.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109326"},"PeriodicalIF":6.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321273","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":"Shakedown limit of 316L stainless steel manufactured by laser powder bed fusion based on crystal plasticity enhanced direct cyclic analysis","authors":"Xuemei Lyu ,&nbsp;Felix Weber ,&nbsp;Geng Chen ,&nbsp;Jiali Zhang ,&nbsp;Tobias Sedlatschek ,&nbsp;Christoph Broeckmann","doi":"10.1016/j.ijfatigue.2025.109325","DOIUrl":"10.1016/j.ijfatigue.2025.109325","url":null,"abstract":"<div><div>Fatigue modelling of metals is essential for accurate prediction of fatigue strength and fatigue life which ensures structural integrity and reliability. The fatigue performance of additively manufactured metals, such as laser powder bed fusion (PBF-LB/M) 316L stainless steel (SS), is highly dependent on the microstructure, making microstructural sensitive models crucial for the modelling. To overcome the expensive computation by traditional incremental analysis, crystal plasticity enhanced direct cyclic analysis was performed to efficiently predict the shakedown limit, i.e. fatigue limit, of PBF-LB/M 316L SS in this work. Statistically equivalent representative volume elements (SERVEs) of the two materials produced with different preheating platform temperatures were generated considering the features of grains and lack of fusion defects. The model parameters were determined and calibrated at microscopic and macroscopic levels. The effect of different dislocation cells on the critical resolved shear stress (CRSS) was incorporated in the model. The statistics of the shakedown limit of the SERVEs show that the defects and the surrounding complex grain interaction resulting from the differences in orientations, shapes, and CRSS comprehensively determine the shakedown limit. The shakedown limit of the two materials is compared with respect to the hierarchical microstructure. A preliminary correlation between the modelled fatigue limit, the CRSS, and the material porosity is proposed. This work advances microstructural sensitive fatigue modelling to improve the fatigue limit prediction for PBF-LB/M 316L SS in aerospace, transportation and medical applications.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109325"},"PeriodicalIF":6.8,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320840","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":"Mechanical responses and microscopic irreversible deformation evolution of thermoplastic fiber-reinforced composites under cyclic loading","authors":"Chen Zhang ,&nbsp;Min Lou ,&nbsp;Yangyang Wang ,&nbsp;Yuxuan Shao ,&nbsp;Dexing Yang ,&nbsp;Titi Sui","doi":"10.1016/j.ijfatigue.2025.109327","DOIUrl":"10.1016/j.ijfatigue.2025.109327","url":null,"abstract":"<div><div>This research investigates the mechanical behavior and irreversible deformation mechanisms of thermoplastic fiber-reinforced composites. First, a nonlinear viscoelastic-elastoplastic constitutive model for the thermoplastic matrix was developed within a parallel rheological framework and calibrated using material tests. Subsequently, a three-dimensional representative volume element model, incorporating randomly distributed fibers and periodic boundary conditions, was established to accurately represent the composite microstructure. Composite specimens were fabricated and subjected to cyclic loading tests. By integrating experimental data with numerical simulations, the study analyzed the composite’s mechanical response under various cyclic loading conditions. Results indicate that stress level, stress ratio, and strain rate significantly influence the macroscopic mechanical response. Concurrently, material geometric features and multi-axial stress states substantially affect microscopic stress distributions and the evolution of irreversible deformation.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109327"},"PeriodicalIF":6.8,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320838","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":"Coupled corrosion and fatigue in reinforced concrete beams: Experimental interpretation of mechanical and electrochemical synergy","authors":"Vivek Vishwakarma ,&nbsp;Sonalisa Ray","doi":"10.1016/j.ijfatigue.2025.109318","DOIUrl":"10.1016/j.ijfatigue.2025.109318","url":null,"abstract":"<div><div>This study investigates the synergistic effects of coupled corrosion–fatigue loading of reinforced concrete beams subjected to simultaneous cyclic loading and electrochemical degradation. A novel two-beam experimental setup was developed to enable direct comparison between coupled and sequential loading conditions. Reinforcement corrosion was accelerated using an impressed current density of 700 <span><math><mi>μ</mi></math></span>A/cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>, and real-time corrosion kinetics were monitored using the Linear Polarization Resistance technique. Lightly reinforced beams were employed to minimize electrochemical complexity and isolate the interaction between localized corrosion and flexural fatigue. Results show that coupled loading reduced fatigue life by 22%–31%, compared to 3%–9% in sequentially loaded beams, relative to plain fatigue specimens. Mid-span deflections at failure in coupled beams were twice as large as in sequential or plain fatigue specimens. Flexural stiffness in coupled specimens exhibited a continuous monotonic decline, whereas sequential beams showed partial recovery. The corrosion current density in coupled specimens increased progressively, in contrast to stabilization after 100,000 cycles in sequential specimen. Microscopy confirmed that fatigue cracks consistently initiated from corrosion pits localized within 1–2 cm of the flexural crack tip in coupled specimens, compared to a broader 7–8 cm distribution in sequential beams. These findings underscore the critical role of pit localization in structural degradation. While mass-loss based assessments have been widely used, this study demonstrates that such global measures do not capture localized damage mechanisms. The insights gained highlight the importance of real-time electrochemical monitoring for service-life prediction of reinforced concrete structures in aggressive environments.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"203 ","pages":"Article 109318"},"PeriodicalIF":6.8,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268442","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}