{"title":"Influence of composite damage on CFRP/steel bonded joint behaviour under cyclic loadings","authors":"Tommaso Papa, Angelo Savio Calabrese, Pierluigi Colombi, Massimiliano Bocciarelli","doi":"10.1016/j.ijfatigue.2025.109113","DOIUrl":"10.1016/j.ijfatigue.2025.109113","url":null,"abstract":"<div><div>High performance adhesives, with augmented fracture toughness, allow to enhance the stress-transfer mechanism in CFRP/steel joints, thus increasing the rate of exploitation of the reinforcement. While existing approaches assume that the mechanical properties of the composite are not affected by the cyclic loading, at large stress levels, close to their static strength, CFRP materials could instead exhibit fatigue damage. In this paper, the influence of CFRP cyclic damage on the fatigue behaviour of CFRP/steel bonded joints is investigated both experimentally and numerically. A residual stiffness method is adopted to model the cyclic nonlinear behaviour of the CFRP lamina. This model is coupled with a cyclic cohesive law accounting for the behaviour of the CFRP/steel interface. The models’ parameters are calibrated using cyclic tensile tests on CFRP coupons and single lap direct shear fatigue tests of the CFRP/steel joints. Parametric analyses are performed by varying the main design parameters. The results show that fatigue damage in the CFRP reinforcement plays a significant role in the joint response. Failure occurred by thin-layer cohesive debonding within the adhesive, localized near the CFRP side. Composite fatigue degradation was found to significantly reduce the number of cycles to failure, especially at low fatigue load ranges.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109113"},"PeriodicalIF":5.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144304879","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":"Crack nucleation and propagation in Ni-based and Ti-based alloys with different ratios σ–1/σ0.2","authors":"Andrey A. Shanyavskiy , Alexey P. Soldatenkov","doi":"10.1016/j.ijfatigue.2025.109109","DOIUrl":"10.1016/j.ijfatigue.2025.109109","url":null,"abstract":"<div><div>The behavior of metals in both low-cycle (LCF) and high-cycle fatigue (HCF) regimes is considered using Ni-based (grade EI698) and Ti-based (grade VT22) alloys. It is shown that the mechanism characterizing the crack initiation in the LCF regime by persistent slip band formation does not correspond to the crack initiation mechanism in the HCF one. Data on the relationship between the yield stress and the fatigue limit of structural materials are generalized and it is revealed that in more than 95 % of metals, the fatigue limit is lower than the yield stress. The regularities of the evolution of hysteresis loops in the EI986 alloy with an increase in the number of loading cycles when fracture occurs under LCF regime are shown, and the absence of hysteresis loops in the VT22 alloy, fractured under HCF regime, is shown at the approximately similar number of cycles. The regularities of fracture relief formation in both alloys are studied, and kinetic curves are plotted by using the measured fatigue striation spacings. A generalized fatigue failure diagram is demonstrated, which, at a ratio of σ<sub>–1</sub>/σ<sub>0.2</sub> ≥ 1, coincides with the previously proposed by Mughrabi, which explains the nature of the subsurface fracture origin formation.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109109"},"PeriodicalIF":5.7,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271085","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}
Anna Mariya Shajan , Raghu Piska , Sundararajan Natarajan
{"title":"Phase-field modeling of fatigue fracture in porous functionally graded materials","authors":"Anna Mariya Shajan , Raghu Piska , Sundararajan Natarajan","doi":"10.1016/j.ijfatigue.2025.109085","DOIUrl":"10.1016/j.ijfatigue.2025.109085","url":null,"abstract":"<div><div>Porous Functionally Graded Materials (PFGM) exhibit complex damage behavior due to the presence of pores. This study presents a hybrid phase-field model to investigate fatigue crack growth in PFGM. The continuous variation of material properties is captured using the Voigt rule of mixtures with uniform porosity, while fatigue effects are incorporated through a fatigue degradation function in the energy functional. Using temperature as an analogous phase field parameter and adapting a staggered solution scheme to solve the coupled governing differential equations, the framework is implemented through a UMAT subroutine feature in ABAQUS. The methodology is validated with results available in the literature, demonstrating its accuracy and robustness. Numerical simulations explore the influence of porosity ratio, power law index, and material gradation on the fatigue fracture behavior under various loading conditions. From a systematic numerical study it is opined that higher porosity levels significantly influence crack propagation paths and load-bearing capacity. Understanding fatigue fracture in PFGM provides valuable insights for optimizing material selection, enhancing structural durability, and improving design strategies for fatigue-critical applications in aerospace and mechanical engineering.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109085"},"PeriodicalIF":5.7,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144304880","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}
Honggen Zhou , Rong Zhou , Guanze Sun , Zihua Zhao
{"title":"The effect of crystallographic orientation and grain boundary misorientation on dwell fatigue crack initiation in a near-α titanium alloy","authors":"Honggen Zhou , Rong Zhou , Guanze Sun , Zihua Zhao","doi":"10.1016/j.ijfatigue.2025.109108","DOIUrl":"10.1016/j.ijfatigue.2025.109108","url":null,"abstract":"<div><div>Understanding the mechanisms of internal crack initiation in dwell fatigue and predicting the crack initiation sites are critical to addressing dwell fatigue failure. This study investigated the dwell fatigue behavior of a near-α titanium alloy TA29, revealing that the average grain boundary misorientation progressively increases with accumulated dwell cycles. Notably, the grain with grain boundary misorientation exceeding 80° was identified as a preferential site for dwell fatigue crack initiation. Grains with transgranular microcrack exhibited characteristic crystallographic orientations, combining a high Schmid factor for basal slip and a c-axis orientation of less than 60° relative to the loading axis. These orientation features were consistently validated in grains containing an internal transgranular microcrack. Beyond considering the intrinsic grain orientation characteristics, a quantitative predictive parameter (Z parameter) was proposed, incorporating the maximum grain boundary misorientation as a representative indicator of severe local stress concentration induced by intergranular interactions. The extremum values of Z parameter effectively predicted grains susceptible to internal dwell fatigue crack initiation. Building upon these findings, the classical Stroh dislocation pile-up model for dwell fatigue was refined by integrating grain boundary misorientation characteristics, providing mechanistic insights into the internal transgranular microcrack initiation under the dwell fatigue.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109108"},"PeriodicalIF":5.7,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263900","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 performance of kiloton CFRP cable after hygrothermal and freeze–thaw cycles","authors":"Jiajun Shi , Rui Guo , Guijun Xian","doi":"10.1016/j.ijfatigue.2025.109103","DOIUrl":"10.1016/j.ijfatigue.2025.109103","url":null,"abstract":"<div><div>The application of carbon fiber reinforced polymer (CFRP) cable with light weight and high strength can improve the service performance of bridge structures in plateau harsh service environments. But the performance evolution behavior of CFRP cable under complicated service environments of fatigue load, hygrothermal and freeze–thaw cycles is unknown. In this paper, the tensile fatigue performance of CFRP rods used for cable before and after hygrothermal and freeze–thaw cycles is investigated experimentally. The tensile fatigue and residual tensile performances of kiloton CFRP cable are verified after hygrothermal and freeze–thaw cycles. Optical frequency domain reflectometry technology is employed to monitor the stiffness degradation of CFRP cables during fatigue loading. The results indicate that the hygrothermal and freeze–thaw cycles release the residual stress within CFRP rod, which improves the fatigue resistance. By contrast, the hygrothermal and freeze–thaw cycles have no significant effect on stiffness degradation of CFRP rod. The kiloton CFRP cable can withstand 2,000 k cycles of tensile fatigue after hygrothermal and freeze–thaw cycles, and the stiffness degradation of CFRP cable is negligible. The residual tensile bearing capacity of CFRP cable after fatigue is 10,731 kN, corresponding to a residual strength retention rate of 105 %. These findings provide essential validation data for the application of kiloton CFRP cables in bridge construction.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109103"},"PeriodicalIF":5.7,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263902","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}
Yilong Cao , Changfeng Yao , Liang Tan , Mincao Cui , Zhaoqing Zhang , Xinyue Li , Biao Xie
{"title":"Vibration fatigue strength prediction of Precision-Milled ATI718 plus alloy Blades: Surface integrity and fatigue performance","authors":"Yilong Cao , Changfeng Yao , Liang Tan , Mincao Cui , Zhaoqing Zhang , Xinyue Li , Biao Xie","doi":"10.1016/j.ijfatigue.2025.109104","DOIUrl":"10.1016/j.ijfatigue.2025.109104","url":null,"abstract":"<div><div>The fatigue performance of blades plays a crucial role in determining the reliability of aeroengines. This study focused on precision-milled ATI718 Plus alloy compressor blades and established a vibration fatigue strength prediction method (VFSP-RR) based on the step-by-step approach. Surface integrity measurements and step-by-step vibration fatigue tests of the blades were conducted to explore the influence mechanism of surface integrity on fatigue performance. Experimental results indicated that the VFSP-RR method achieved a prediction accuracy exceeding 88.9% for blade vibration fatigue strength. The surface integrity of precision-milled blades exhibited significant anisotropy, with the maximum residual compressive stress and roughness in the blade height direction being 183.3% and 171.7% greater than those in the chord direction, respectively. Further computational analysis elaborated on the anisotropic effects of residual stress and roughness on fatigue performance: increasing the residual compressive stress in the blade height direction significantly improved the blade’s fatigue life, whereas an increase in roughness in the blade height direction drastically reduced fatigue life. This study enhances the understanding of the relationship between surface integrity and fatigue performance in precision-milled blades, providing theoretical support and methodological references for fatigue-resistant blade manufacturing.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109104"},"PeriodicalIF":5.7,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144279591","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":"Volumetric measurement of fatigue crack cavity in homogeneous materials based on reversed digital volume correlation","authors":"Haodi Tang , Derui Li , Bin Cheng , Zhixu Dong","doi":"10.1016/j.ijfatigue.2025.109106","DOIUrl":"10.1016/j.ijfatigue.2025.109106","url":null,"abstract":"<div><div>For homogeneous materials, the internal uniform composition with unrecognizable textures hinders effective deformation tracking when using the Digital Volume Correlation (DVC) technique to detect internal imperfections. This study proposes a novel method for measuring fatigue crack cavity propagation by which such limitations can be overcome. A reversed correlation strategy of DVC, which capitalizes on fracture-induced textures to enhance speckle contrast, is introduced to enable precise evaluation of point cloud correlation variations for crack identification. A coarse-to-fine point cloud arrangement scheme is proposed to balance measurement accuracy and computational efficiency. A crack cavity identification approach is introduced to capitalize on the decorrelation effect induced by texture evolution so that critical crack surface points can be extracted. The presented method, combined with point cloud analysis, enables geometric reconstruction of crack cavity and quantitative measurement of key parameters including propagation dimensions, surface area, and cavity volume. The approach reduces noise-induced errors, a primary limitation affecting accuracy of conventional deformation field-based DVC methods, and provides accurate results even under large deformation conditions. The feasibility and precision of the method are validated by numerical simulations, demonstrating it could be a robust and reliable alternative for using DVC to measure fatigue crack cavity in homogeneous materials.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109106"},"PeriodicalIF":5.7,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144263901","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}
M. Kreins , H. Kannan , S. Scherbring , A. Bührig-Polaczek , J. Tenkamp , F. Walther , W. Michels , U. Krupp
{"title":"The significance of microstructure heterogeneities on the VHCF life of cast aluminum alloys","authors":"M. Kreins , H. Kannan , S. Scherbring , A. Bührig-Polaczek , J. Tenkamp , F. Walther , W. Michels , U. Krupp","doi":"10.1016/j.ijfatigue.2025.109105","DOIUrl":"10.1016/j.ijfatigue.2025.109105","url":null,"abstract":"<div><div>The very high cycle fatigue (VHCF) of cast aluminum is strongly associated with casting defects and microstructure features, e.g. porosity, (secondary) dendrite arm spacing (SDAS) and intermetallics. Complex components have an inhomogeneous microstructure due to locally varying solidification conditions. Due to complex geometries, directional solidification and sufficient feeding are often not possible, giving rise to solidification defects and shrinkage pores. These microstructural aspects influence the service life, as demonstrated by fatigue tests on automotive engine blocks and cylinder heads. However, understanding the damage process and correlating it with the microstructure is difficult due to the large number of influencing factors and their interdependencies. To this end, laboratory melts with controlled microstructure evolution were used, allowing a variation of SDAS, eutectic Si and pores under otherwise identical boundary conditions. Mechanical resonance and ultrasonic fatigue testing in combination with high-resolution microstructure analysis show a reduction in fatigue life with increasing SDAS. Main reasons are large α-aluminum cells, which provide low resistance to crack propagation. The impact of pores is depending on their size, shape and location. Large fissured pores in near-surface regions act as crack initiators, whereas small spherical pores can retard crack propagation due to crack deflection and crack tip blunting.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109105"},"PeriodicalIF":5.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290548","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}
Florent Alexis , Sylvie Castagnet , Carole Nadot-Martin , Gilles Robert , Peggy Havet
{"title":"Influence of acid environment on the fatigue behavior of short glass fiber polyamide 6/6.6 (35% wt.) composites","authors":"Florent Alexis , Sylvie Castagnet , Carole Nadot-Martin , Gilles Robert , Peggy Havet","doi":"10.1016/j.ijfatigue.2025.109084","DOIUrl":"10.1016/j.ijfatigue.2025.109084","url":null,"abstract":"<div><div>This study investigates the impact of a low-pH acidic aqueous solution on the fatigue behavior of short glass fiber-reinforced polyamide composites (PA6 and PA6.6, 35 % wt.). Mechanical tests were conducted under aging conditions (RH90, 60 °C) with fixed parameters (f = 1–3 Hz, R = 0.1), considering anisotropy with three orientations (0°, 45°, and 90°). A specialized chamber was developed for in-situ fatigue testing in an acid-heated solution. The study tracked mass and dimensions during aging and compared them with data from demineralized water. Results indicate that acid exposure significantly degrades the fiber–matrix interface, leading to increased fiber pullout and reduced mechanical integrity. PA6 composites exhibit better hydrolytic stability compared to PA6.6. This research provides critical insights into the durability of SFRP composites in acidic environments, relevant for automotive applications such as EGR (Exhaust Gas Recirculation) systems.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109084"},"PeriodicalIF":5.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241608","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}
Meng He , Lei Yang , Chao Zhao , Ronghong Zhang , Danna Tang , Liang Hao
{"title":"Revealing anisotropic fatigue behavior and multiscale failure mechanisms of bio-inspired heterogeneous glass sponge lattice structures fabricated by laser powder bed fusion under high-cycle compression fatigue","authors":"Meng He , Lei Yang , Chao Zhao , Ronghong Zhang , Danna Tang , Liang Hao","doi":"10.1016/j.ijfatigue.2025.109093","DOIUrl":"10.1016/j.ijfatigue.2025.109093","url":null,"abstract":"<div><div>Lattice structures (LSs) fabricated via additive manufacturing (AM) are widely used for their lightweight, high strength-to-weight ratio, and energy absorption properties. However, the long-term fatigue performance of metallic lattice structures (MLSs) remains challenging, primarily due to structural failure and manufacturing defects. This study investigates the dynamic compressive fatigue behavior of bio-inspired glass sponge lattice structures (GSLSs) and their variants. Combining micro-CT characterization reveals a structure–property relationship where nodal geometry optimization improves fabrication quality and fatigue performance. Results show that GSLS achieves the highest fatigue strength (0.7 <span><math><mrow><msub><mi>F</mi><mrow><mi>max</mi></mrow></msub></mrow></math></span> = 17.897 kN) at 10<sup>4</sup> cycles, while GSLS-I exhibits the highest fatigue strength (<span><math><mrow><msub><mi>N</mi><mi>f</mi></msub></mrow></math></span>) at 10⁶ cycles (0.7 <span><math><mrow><msub><mi>F</mi><mrow><mi>max</mi></mrow></msub></mrow></math></span> = 11.827 kN). Meanwhile, failure mode analysis shows that stress concentrations at nodes and horizontal overhangs accelerate crack initiation, explaining the more excellent fatigue stability of GSLS, GSLS-II, and GSLS-S (R<sup>2</sup> = 0.99, 0.95, and 0.96) compared to GSLS-I and GSLS-III (R<sup>2</sup> = 0.69 and 0.76). Finite element analysis (FEA) further elucidates fatigue failure mechanisms, confirming cyclic ratcheting and strut-level stress distribution as key factors influencing fracture. This study provides a predictive framework for fatigue failure in MLSs and offers insights into optimizing high-performance LSs for aerospace, automotive, biomedical implants, and other engineering applications.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"200 ","pages":"Article 109093"},"PeriodicalIF":5.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213312","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}