Pub Date : 2026-01-12DOI: 10.1016/j.ijfatigue.2026.109487
Hao Zhang , Daoxin Liu , Jing Yang , Mengyao Li , Junnan Wu , Yueyang Li , Yanjie Liu , Yu Zhang , Xiaohua Zhang , Chang Ye
Laser assisted ultrasonic surface rolling process (LA-USRP) was applied to GH4169 superalloy to improve its high temperature fretting fatigue resistance. Conventional USRP increased the fretting fatigue life under axial tension–tension cyclic loading (stress ratio R = 0.1, frequency of 131 ± 2 Hz, maximum stress of 800 MPa, and contact pressure of 85 MPa) at 600 °C by a factor of 3.3, whereas LA-USRP achieved a 14.7-fold enhancement compared to the base material. This superior performance is primarily attributed to advantageous microstructural evolution, including a thicker gradient nanostructured surface layer (average surface grain size around 25 nm), higher compressive residual stresses (surface −2079 MPa, maximum −2443 MPa at around 35 μm depth), and the formation of refined nanotwins and stabilized 9R phase. These features significantly improve cyclic stability of compressive residual stresses (relaxation reduced from 89.6 % in USRP to 35.9 % in LA-USRP after fatigue) and impede dislocation motion at elevated temperatures. These findings offer a promising approach for enhancing the high temperature fretting fatigue performance of critical aero-engine components.
{"title":"Microstructural evolution for enhanced high temperature fretting fatigue resistance in GH4169 via laser assisted ultrasonic surface rolling process","authors":"Hao Zhang , Daoxin Liu , Jing Yang , Mengyao Li , Junnan Wu , Yueyang Li , Yanjie Liu , Yu Zhang , Xiaohua Zhang , Chang Ye","doi":"10.1016/j.ijfatigue.2026.109487","DOIUrl":"10.1016/j.ijfatigue.2026.109487","url":null,"abstract":"<div><div>Laser assisted ultrasonic surface rolling process (LA-USRP) was applied to GH4169 superalloy to improve its high temperature fretting fatigue resistance. Conventional USRP increased the fretting fatigue life under axial tension–tension cyclic loading (stress ratio R = 0.1, frequency of 131 ± 2 Hz, maximum stress of 800 MPa, and contact pressure of 85 MPa) at 600 °C by a factor of 3.3, whereas LA-USRP achieved a 14.7-fold enhancement compared to the base material. This superior performance is primarily attributed to advantageous microstructural evolution, including a thicker gradient nanostructured surface layer (average surface grain size around 25 nm), higher compressive residual stresses (surface −2079 MPa, maximum −2443 MPa at around 35 μm depth), and the formation of refined nanotwins and stabilized 9R phase. These features significantly improve cyclic stability of compressive residual stresses (relaxation reduced from 89.6 % in USRP to 35.9 % in LA-USRP after fatigue) and impede dislocation motion at elevated temperatures. These findings offer a promising approach for enhancing the high temperature fretting fatigue performance of critical aero-engine components.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109487"},"PeriodicalIF":6.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956823","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}
Pub Date : 2026-01-12DOI: 10.1016/j.ijfatigue.2026.109498
Tao Huang , Chunfeng Wan , Tingbin Liu , Yucheng Zhang , Xiangtao Lu , Youliang Ding , Hanwei Zhao , Changqing Miao , Songtao Xue
The study of the fatigue performance of corroded steel wires in bridge cables holds significant scientific value for advancing structural theory and informing engineering practice. To address key challenges in fatigue life prediction such as the scarcity of the complexity of nonlinear relationships and the lack of model interpretability, this study proposes a progressive solution framework consisting of integrated optimization, transfer validation, model interpretation, platform development. A dual-source heterogeneous database (A/B) was first constructed by integrating 422 sets of specimens data from the literature with 30 sets of experimental data obtained through independently conducted corrosion tests. An integration strategy based on stacked-transfer models is used to couple the strengths of six different machine learning (ML) models. The improved sparrow optimisation (ISSA) algorithm was employed for hyperparameter optimization. The results demonstrate that the proposed Stacking model surpasses both individual base learners and existing mathematical models from literature and specifications in prediction accuracy. When transferred to new independent datasets, the model maintains excellent predictive performance, validating its strong generalization capability. Furthermore, by incorporating the SHAP framework, the study systematically deciphers the model’s decision-making mechanism and quantifies the contribution distribution of individual parameters to fatigue life. Finally, to enhance model applicability, a web-based human–computer interaction platform for intelligent fatigue life prediction was developed based on the stacking-SHAP model. This study provides a data-algorithm-platform trinity solution for the whole life cycle management of bridge cables.
{"title":"Data-driven fatigue life prediction of corroded steel wires: A transfer learning on stacking interpretable model and feature sensitivity analysis","authors":"Tao Huang , Chunfeng Wan , Tingbin Liu , Yucheng Zhang , Xiangtao Lu , Youliang Ding , Hanwei Zhao , Changqing Miao , Songtao Xue","doi":"10.1016/j.ijfatigue.2026.109498","DOIUrl":"10.1016/j.ijfatigue.2026.109498","url":null,"abstract":"<div><div>The study of the fatigue performance of corroded steel wires in bridge cables holds significant scientific value for advancing structural theory and informing engineering practice. To address key challenges in fatigue life prediction such as the scarcity of the complexity of nonlinear relationships and the lack of model interpretability, this study proposes a progressive solution framework consisting of integrated optimization, transfer validation, model interpretation, platform development. A dual-source heterogeneous database (A/B) was first constructed by integrating 422 sets of specimens data from the literature with 30 sets of experimental data obtained through independently conducted corrosion tests. An integration strategy based on stacked-transfer models is used to couple the strengths of six different machine learning (ML) models. The improved sparrow optimisation (ISSA) algorithm was employed for hyperparameter optimization. The results demonstrate that the proposed Stacking model surpasses both individual base learners and existing mathematical models from literature and specifications in prediction accuracy. When transferred to new independent datasets, the model maintains excellent predictive performance, validating its strong generalization capability. Furthermore, by incorporating the SHAP framework, the study systematically deciphers the model’s decision-making mechanism and quantifies the contribution distribution of individual parameters to fatigue life. Finally, to enhance model applicability, a web-based human–computer interaction platform for intelligent fatigue life prediction was developed based on the stacking-SHAP model. This study provides a data-algorithm-platform trinity solution for the whole life cycle management of bridge cables.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109498"},"PeriodicalIF":6.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956822","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}
Pub Date : 2026-01-10DOI: 10.1016/j.ijfatigue.2026.109486
Indrajit Nandi , Sajith Soman , Reza Molaei , Will Tilson , Nima Shamsaei , Shuai Shao
This study investigates the competing role of volumetric defects and microstructure on the fatigue behavior of additively manufactured Inconel 718 (IN718), with emphasis on the crack initiation mechanism. IN718 rods were fabricated using laser powder bed fusion with tuned process parameters and heat treatments to obtain diverse defect contents and microstructures. Both uniaxial tensile and fully-reversed, force-controlled fatigue tests were performed, and fractography was conducted to analyze various features observed at fatigue crack initiation sites. The influence of defects and microstructure was more pronounced on fatigue behavior than on tensile behavior. Both microstructure- and defect-mediated fatigue crack initiations were observed. For the former, facets were observed at the crack initiation sites which were due to the formation and operation of persistent slip bands. Interestingly, results revealed a similar dependence of fatigue life on the feature size at the crack initiation sites, regardless of the crack initiation mechanism.
{"title":"Competing role of volumetric defects and microstructure on the fatigue behavior of additively manufactured Inconel 718: An experimental study","authors":"Indrajit Nandi , Sajith Soman , Reza Molaei , Will Tilson , Nima Shamsaei , Shuai Shao","doi":"10.1016/j.ijfatigue.2026.109486","DOIUrl":"10.1016/j.ijfatigue.2026.109486","url":null,"abstract":"<div><div>This study investigates the competing role of volumetric defects and microstructure on the fatigue behavior of additively manufactured Inconel 718 (IN718), with emphasis on the crack initiation mechanism. IN718 rods were fabricated using laser powder bed fusion with tuned process parameters and heat treatments to obtain diverse defect contents and microstructures. Both uniaxial tensile and fully-reversed, force-controlled fatigue tests were performed, and fractography was conducted to analyze various features observed at fatigue crack initiation sites. The influence of defects and microstructure was more pronounced on fatigue behavior than on tensile behavior. Both microstructure- and defect-mediated fatigue crack initiations were observed. For the former, facets were observed at the crack initiation sites which were due to the formation and operation of persistent slip bands. Interestingly, results revealed a similar dependence of fatigue life on the feature size at the crack initiation sites, regardless of the crack initiation mechanism.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109486"},"PeriodicalIF":6.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956827","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}
Pub Date : 2026-01-10DOI: 10.1016/j.ijfatigue.2026.109484
Lu Ke , Youlin Li , Chuanxi Li , Xu Jiang , Jun Ye , Ailong Chen , Guojin Li
Fatigue cracks in steel elements repaired with traditional crack-stop holes are susceptible to perforation, enabling propagation and resulting in inadequate fatigue life improvement. The fatigue performance of cracked steel elements repaired by cold-expanded crack-stop holes was experimentally investigated, and the effects of cold expansion ratios and hole-to-crack tip distances on the fatigue life were examined. Finite element (FE) simulation tests were conducted to reveal the residual stress distributions around the crack-stop holes after cold expansion. The results show that higher cold expansion ratios significantly enhance fatigue life under an identical hole-to-crack tip distance. When the hole-to-crack tip distance was 0 mm, a cold expansion ratio of 2% yielded the greatest fatigue life improvement, with a 50.82% increase compared to specimens without cold expansion. Moreover, the residual stress was distributed nonlinearly along the thickness direction of the steel elements, with the peak residual stress occurring near the exit side of the cold expansion mandrel. Finally, based on the critical distance theory and residual stress weight allocation coefficient, a fatigue life prediction model for the crack initiation at the hole edges was developed. Simultaneously, based on linear elastic fracture mechanics, a fatigue life prediction model for the crack growth was proposed. The results indicated that the experimental and predicted values of the total fatigue life are in good agreement. This study offers a cold expansion technique for crack-stop holes, providing a novel technique for extending the fatigue life of cracked steel structures.
{"title":"Fatigue mechanisms and life prediction of cracked steel elements repaired with cold-expanded crack-stop holes","authors":"Lu Ke , Youlin Li , Chuanxi Li , Xu Jiang , Jun Ye , Ailong Chen , Guojin Li","doi":"10.1016/j.ijfatigue.2026.109484","DOIUrl":"10.1016/j.ijfatigue.2026.109484","url":null,"abstract":"<div><div>Fatigue cracks in steel elements repaired with traditional crack-stop holes are susceptible to perforation, enabling propagation and resulting in inadequate fatigue life improvement. The fatigue performance of cracked steel elements repaired by cold-expanded crack-stop holes was experimentally investigated, and the effects of cold expansion ratios and hole-to-crack tip distances on the fatigue life were examined. Finite element (FE) simulation tests were conducted to reveal the residual stress distributions around the crack-stop holes after cold expansion. The results show that higher cold expansion ratios significantly enhance fatigue life under an identical hole-to-crack tip distance. When the hole-to-crack tip distance was 0 mm, a cold expansion ratio of 2% yielded the greatest fatigue life improvement, with a 50.82% increase compared to specimens without cold expansion. Moreover, the residual stress was distributed nonlinearly along the thickness direction of the steel elements, with the peak residual stress occurring near the exit side of the cold expansion mandrel. Finally, based on the critical distance theory and residual stress weight allocation coefficient, a fatigue life prediction model for the crack initiation at the hole edges was developed. Simultaneously, based on linear elastic fracture mechanics, a fatigue life prediction model for the crack growth was proposed. The results indicated that the experimental and predicted values of the total fatigue life are in good agreement. This study offers a cold expansion technique for crack-stop holes, providing a novel technique for extending the fatigue life of cracked steel structures.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109484"},"PeriodicalIF":6.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956818","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}
Pub Date : 2026-01-09DOI: 10.1016/j.ijfatigue.2026.109488
Danqi Zhang , Chen Shen , Lin Wang , Wenlu Zhou , Ting Zhang , Ying Li , Yuelong Zhang , Fang Li , Jianwen Xin , Kanglong Wu , Gang Ruan , Xueming Hua
As a critical milestone of twin-wire directed energy deposition-arc (TW-DED-arc) technology, we present the first report on the excellent fatigue crack growth (FCG) performance of a Ti–48Al–2Cr–2Nb (TiAl-4822) alloy with a refined fully-lamellar microstructure. FCG tests conducted on standard compact tension specimens from two orthogonal directions under cyclic loading at 650 °C (R = 0.1) demonstrated a high fatigue threshold (∼8.0 MPa·m1/2) and low crack propagation rates compared to conventionally manufactured counterparts. The isotropic microstructure rendered crack resistance insensitive to deposition direction. In-situ tensile analysis under electron back scattered diffraction revealed that the enhanced performance originates from refined lamellar spacing, which promoted super-dislocation (SD) activity. Tortuous crack paths formed by mortise–tenon interlocks in inter-lamellar crack and zigzag trans-lamellar cracking, which effectively deflected cracks and dissipate energy. Furthermore, high volume fraction of γ-phase (89.4%) with low stacking fault energy facilitated dislocation dissociation and deformation twinning (DT). These mechanisms collectively enhanced stress relaxation through twin interactions and SD immobilization, significantly improving crack resistance. This study not only reports a previously undocumented property profile but also underscores the technological potential of TW-DED-arc for manufacturing high-performance titanium aluminide components.
{"title":"Fully-lamellar equiaxed structure mediated excellent high-temperature fatigue crack growth resistance of Ti-48Al-2Cr-2Nb alloy fabricated via twin-wire directed energy deposition-arc process","authors":"Danqi Zhang , Chen Shen , Lin Wang , Wenlu Zhou , Ting Zhang , Ying Li , Yuelong Zhang , Fang Li , Jianwen Xin , Kanglong Wu , Gang Ruan , Xueming Hua","doi":"10.1016/j.ijfatigue.2026.109488","DOIUrl":"10.1016/j.ijfatigue.2026.109488","url":null,"abstract":"<div><div>As a critical milestone of twin-wire directed energy deposition-arc (TW-DED-arc) technology, we present the first report on the excellent fatigue crack growth (FCG) performance of a Ti–48Al–2Cr–2Nb (TiAl-4822) alloy with a refined fully-lamellar microstructure. FCG tests conducted on standard compact tension specimens from two orthogonal directions under cyclic loading at 650 °C (R = 0.1) demonstrated a high fatigue threshold (∼8.0 MPa·m<sup>1/2</sup>) and low crack propagation rates compared to conventionally manufactured counterparts. The isotropic microstructure rendered crack resistance insensitive to deposition direction. In-situ tensile analysis under electron back scattered diffraction revealed that the enhanced performance originates from refined lamellar spacing, which promoted super-dislocation (SD) activity. Tortuous crack paths formed by mortise–tenon interlocks in inter-lamellar crack and zigzag <em>trans</em>-lamellar cracking, which effectively deflected cracks and dissipate energy. Furthermore, high volume fraction of γ-phase (89.4%) with low stacking fault energy facilitated dislocation dissociation and deformation twinning (DT). These mechanisms collectively enhanced stress relaxation through twin interactions and SD immobilization, significantly improving crack resistance. This study not only reports a previously undocumented property profile but also underscores the technological potential of TW-DED-arc for manufacturing high-performance titanium aluminide components.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109488"},"PeriodicalIF":6.8,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956830","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}
Interlaminar defects such as voids and incomplete fibre–matrix consolidation limit the fatigue performance of additively manufactured (AM) continuous-fibre composites. This study examines how thermal post-processing influences Mode I (DCB) and Mode II (ENF) fatigue crack-growth behaviour in 3D-printed CF/PA laminates. Across all load levels, post-processed specimens showed substantially improved fatigue resistance, requiring approximately 40–50% higher energy-release rates to reach the same crack-growth rates as the as-printed material. Crack-length–versus-cycle curves further demonstrated that post-processed specimens endured significantly more cycles to reach equivalent crack lengths. Microscopy revealed distinct mechanisms underlying these improvements: void elimination and smoother crack planes in Mode I, and increased crack-face contact and frictional dissipation along shear-sliding surfaces in Mode II. Finite-element simulations using the CF20 fatigue cohesive model reproduced the experimental trends with minimal calibration. Overall, thermal post-processing provides a simple and effective pathway to enhance the fatigue durability of additively manufactured composite laminates.
{"title":"Investigating the influence of thermal Post-Processing on the Mode I and Mode II fatigue fracture resistance of additively manufactured carbon Fiber composites","authors":"Zane Forbes , Xiaobo Yu , Garth Pearce , Mathew W Joosten","doi":"10.1016/j.ijfatigue.2026.109485","DOIUrl":"10.1016/j.ijfatigue.2026.109485","url":null,"abstract":"<div><div>Interlaminar defects such as voids and incomplete fibre–matrix consolidation limit the fatigue performance of additively manufactured (AM) continuous-fibre composites. This study examines how thermal post-processing influences Mode I (DCB) and Mode II (ENF) fatigue crack-growth behaviour in 3D-printed CF/PA laminates. Across all load levels, post-processed specimens showed substantially improved fatigue resistance, requiring approximately 40–50% higher energy-release rates to reach the same crack-growth rates as the as-printed material. Crack-length–versus-cycle curves further demonstrated that post-processed specimens endured significantly more cycles to reach equivalent crack lengths. Microscopy revealed distinct mechanisms underlying these improvements: void elimination and smoother crack planes in Mode I, and increased crack-face contact and frictional dissipation along shear-sliding surfaces in Mode II. Finite-element simulations using the CF20 fatigue cohesive model reproduced the experimental trends with minimal calibration. Overall, thermal post-processing provides a simple and effective pathway to enhance the fatigue durability of additively manufactured composite laminates.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109485"},"PeriodicalIF":6.8,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956832","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}
Pub Date : 2026-01-07DOI: 10.1016/j.ijfatigue.2026.109481
Alessio Centola , Alberto Ciampaglia , Carlo Boursier Niutta , Filippo Berto , Davide Salvatore Paolino , Andrea Tridello
The present paper presents two novel data-driven topology optimization (TO) procedures to design lighter additively manufactured (AM) fatigue resistant components. The first TO method is driven by a probabilistic machine learning (ML) algorithm based on a Bayesian Neural Network (BNN), trained on fatigue data from the literature to assess probabilistic stress-life (PSN) curves. These curves are used to predict the allowable design stress for TO and are predicted directly from AM process parameters, the risk volume, and thermal and surface treatments. The second TO design procedure is instead driven by another BNN, trained to predict the maximum critical defect size from the process parameters. The TO limit stress is computed from the predicted critical defect and the threshold stress intensity factor Kth. After the TO, the critical stress intensity factor KI in the component is computed and compared against Kth, to assess the effectiveness of this design procedure. These two frameworks are applied to the design of an SS316L automotive suspension lower control arm and a Ti6Al4V aerospace bracket, respectively. With the following framework, the limit stress calculation does not require specifically designed experimental campaigns and prototyping, as previously sparse experimental knowledge can be embedded in a powerful design tool, which allows for preventing fatigue failures, while accounting directly for the influence of the AM process parameters.
{"title":"Data driven topology optimization of AM parts accounting for process-affected fatigue performance: Application to automotive and aerospace components","authors":"Alessio Centola , Alberto Ciampaglia , Carlo Boursier Niutta , Filippo Berto , Davide Salvatore Paolino , Andrea Tridello","doi":"10.1016/j.ijfatigue.2026.109481","DOIUrl":"10.1016/j.ijfatigue.2026.109481","url":null,"abstract":"<div><div>The present paper presents two novel data-driven topology optimization (TO) procedures to design lighter additively manufactured (AM) fatigue resistant components. The first TO method is driven by a probabilistic machine learning (ML) algorithm based on a Bayesian Neural Network (BNN), trained on fatigue data from the literature to assess probabilistic stress-life (PSN) curves. These curves are used to predict the allowable design stress for TO and are predicted directly from AM process parameters, the risk volume, and thermal and surface treatments. The second TO design procedure is instead driven by another BNN, trained to predict the maximum critical defect size from the process parameters. The TO limit stress is computed from the predicted critical defect and the threshold stress intensity factor <em>K<sub>th</sub></em>. After the TO, the critical stress intensity factor <em>K<sub>I</sub></em> in the component is computed and compared against <em>K<sub>th</sub></em>, to assess the effectiveness of this design procedure. These two frameworks are applied to the design of an SS316L automotive suspension lower control arm and a Ti6Al4V aerospace bracket, respectively. With the following framework, the limit stress calculation does not require specifically designed experimental campaigns and prototyping, as previously sparse experimental knowledge can be embedded in a powerful design tool, which allows for preventing fatigue failures, while accounting directly for the influence of the AM process parameters.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109481"},"PeriodicalIF":6.8,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956833","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}
Pub Date : 2026-01-06DOI: 10.1016/j.ijfatigue.2026.109483
Matheus Garcia do Vale , Thiago Roberto Felisardo Cavalcante , Gualter Silva Pereira , Julián Arnaldo Ávila Díaz , José Luiz Boldrini , Marco Lúcio Bittencourt
Fatigue crack growth critically influences the lifespan of structural components in high-demanding engineering applications. Despite advances in phase-field fracture models, cycle-by-cycle simulations remain computationally prohibitive and often rely on extrapolation techniques. This work introduces a novel energy-based fatigue degradation evolution equation within a phase-field framework, enabling direct recovery of the Paris-law behavior without the need for explicit cycle-jumping algorithms. We implement a staggered solution scheme and employ a constant- loading procedure to compute crack growth rates in selected stress intensity ranges. The proposed strategy is effective in calibrating simulation parameters, resulting in a reduction of up to 97% in simulated cycles. Additionally, we utilize an automatic crack length measurement algorithm based on the A* pathfinder heuristic, which minimizes user intervention and mesh dependence. Validation with experimental data for the WE43 and AA7050 alloys shows excellent agreement in the Paris plots, while reducing computational costs. The proposed methodology offers a robust and efficient tool for material characterization and fatigue analysis in brittle-to-ductile materials.
{"title":"Fitting of an FCG test of the WE43C and AA7050 alloys using two phase-fields and a Constant-ΔK approach","authors":"Matheus Garcia do Vale , Thiago Roberto Felisardo Cavalcante , Gualter Silva Pereira , Julián Arnaldo Ávila Díaz , José Luiz Boldrini , Marco Lúcio Bittencourt","doi":"10.1016/j.ijfatigue.2026.109483","DOIUrl":"10.1016/j.ijfatigue.2026.109483","url":null,"abstract":"<div><div>Fatigue crack growth critically influences the lifespan of structural components in high-demanding engineering applications. Despite advances in phase-field fracture models, cycle-by-cycle simulations remain computationally prohibitive and often rely on extrapolation techniques. This work introduces a novel energy-based fatigue degradation evolution equation within a phase-field framework, enabling direct recovery of the Paris-law behavior without the need for explicit cycle-jumping algorithms. We implement a staggered solution scheme and employ a constant-<span><math><mrow><mi>Δ</mi><mi>K</mi></mrow></math></span> loading procedure to compute crack growth rates in selected stress intensity ranges. The proposed strategy is effective in calibrating simulation parameters, resulting in a reduction of up to 97% in simulated cycles. Additionally, we utilize an automatic crack length measurement algorithm based on the A* pathfinder heuristic, which minimizes user intervention and mesh dependence. Validation with experimental data for the WE43 and AA7050 alloys shows excellent agreement in the Paris plots, while reducing computational costs. The proposed methodology offers a robust and efficient tool for material characterization and fatigue analysis in brittle-to-ductile materials.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109483"},"PeriodicalIF":6.8,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922150","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}
Pub Date : 2026-01-04DOI: 10.1016/j.ijfatigue.2026.109482
Mehdi Aghabagloo , Laura Carreras , José Sena-Cruz , Marta Baena
Although the bond behavior and failure modes of externally bonded reinforcement (EBR) fiber-reinforced polymer (FRP) and hybrid-bonded (HB) systems on concrete have been widely investigated under quasi-static loading, their performance under fatigue loading remains insufficiently understood. Existing research on RC structures strengthened with carbon FRP (CFRP) under cyclic loading has predominantly focused on demonstrating improvements in fatigue life. However, far less attention has been given to examining the bond behavior and the rate of debonding growth, factors that are critical to ensuring the long-term effectiveness and durability of externally bonded CFRP systems. This study experimentally examines the performance of EBR and HB CFRP-to-concrete bonded joints subjected to cyclic fatigue loading. The investigation focuses on the progression of fatigue-induced damage in bonded joints tested under direct pull-out conditions, using CFRP laminates exposed to different maximum cyclic load levels (relative to the static failure load) while keeping a constant load ratio. Under fatigue loading, interfacial debonding between the CFRP laminate and the adhesive was observed, whereas quasi-static tests typically resulted in cohesive failure within the concrete. Results also revealed that increasing the maximum cyclic load markedly accelerated the rate of debonding propagation.
{"title":"Fatigue behavior of externally bonded and hybrid-bonded carbon fiber reinforced polymer–to–concrete joints","authors":"Mehdi Aghabagloo , Laura Carreras , José Sena-Cruz , Marta Baena","doi":"10.1016/j.ijfatigue.2026.109482","DOIUrl":"10.1016/j.ijfatigue.2026.109482","url":null,"abstract":"<div><div>Although the bond behavior and failure modes of externally bonded reinforcement (EBR) fiber-reinforced polymer (FRP) and hybrid-bonded (HB) systems on concrete have been widely investigated under quasi-static loading, their performance under fatigue loading remains insufficiently understood. Existing research on RC structures strengthened with carbon FRP (CFRP) under cyclic loading has predominantly focused on demonstrating improvements in fatigue life. However, far less attention has been given to examining the bond behavior and the rate of debonding growth, factors that are critical to ensuring the long-term effectiveness and durability of externally bonded CFRP systems. This study experimentally examines the performance of EBR and HB CFRP-to-concrete bonded joints subjected to cyclic fatigue loading. The investigation focuses on the progression of fatigue-induced damage in bonded joints tested under direct pull-out conditions, using CFRP laminates exposed to different maximum cyclic load levels (relative to the static failure load) while keeping a constant load ratio. Under fatigue loading, interfacial debonding between the CFRP laminate and the adhesive was observed, whereas quasi-static tests typically resulted in cohesive failure within the concrete. Results also revealed that increasing the maximum cyclic load markedly accelerated the rate of debonding propagation.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109482"},"PeriodicalIF":6.8,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897490","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}
Pub Date : 2026-01-03DOI: 10.1016/j.ijfatigue.2025.109480
Kangkai Song , Conghui Zhang , Tongguang Zhai , Wenguang Zhu , Shuaiyang Liu , Ruixuan Tian , Guoliang Liu , Jinping Wang
Understanding fatigue crack propagation (FCP) in Zr-2.5Nb alloy is crucial for safely shutting down the reactor before crack propagation to instability. This study quantitatively investigated the FCP behavior in a α/β Zr-2.5Nb alloy in combination with four crystallographic parameters (geometric compatibility factor (m’), Schmidt factor (SF), effective driving force (D), and twist angle ()). The results indicated that the strength and initial crack propagation resistance were improved with the increase of the β-phase. However, the initial FCP rate increased when the α-martensitic transformation occurred in the β-phase. Quantitative analysis indicated that transgranular cracks propagate primarily along prismatic and pyramidal planes in α phase, while along the (1 1 0) and (1 1 1) planes in the β phase. Cracks propagated along the slip plane if SF >0.3 and D <0.7, but along the plane of maximum driving planes if D >0.7 and SF <0.3. FCP across the phase boundary was related to and m’; crack deflection was significantly observed at the phase boundary when > 40° and m’ < 0.4. Finally, the effects of residual β phase and martensitic transformation on the crack growth rate were discussed. This work contributes to understanding the critical role of the β phase in FCP within Zr alloys and provides new ideas for enhancing FCP resistance.
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