International Journal of Fatigue最新文献_第4页

Defect-based multiaxial fatigue life assessment of 3D-printed bulk metallic glasses 基于缺陷的3d打印大块金属玻璃多轴疲劳寿命评估

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-27 DOI: 10.1016/j.ijfatigue.2026.109528

Songyun Ma , Hongshi Ruan , Jianye Shi , Cécile Chaxel , Shuai Wei , Moritz Stolpe , Peilei Zhang , Yangjian Xu , Bernd Markert

Additive manufacturing unlocks near-net-shape production of bulk metallic glass (BMG) components with complex geometries. Nevertheless, their durability under multiaxial cyclic loadings remains largely unexplored and poorly understood. In this work, the multiaxial fatigue behaviour of selective laser melting (SLM) fabricated Zr-based BMG with composition

{Zr}_{59.3} {Cu}_{28.8} {Nb}_{1.5} {Al}_{10.4}

is investigated. In multiaxial fatigue experiments, 17 specimens with approximately 0.46% porosity were subjected to stress-controlled cyclic loadings, including both proportional and non-proportional loading paths. The fracture morphology and multiaxial fatigue mechanisms were systematically analysed using SEM micrographs. To evaluate the fatigue life of 3D-printed BMGs while accounting for manufacturing-induced defects, we conducted defect-based computational simulations using representative volume element (RVE) models incorporating a single pore defect. Parametric studies were carried out to examine the influence of pore location on multiaxial fatigue life performance. Based on the FEM simulation results, a modified non-local Dang Van criterion is proposed for predicting the multiaxial fatigue life. In the critical plane model, a non-proportional correction coefficient is introduced based on the principal stress at the critical location in the vicinity of the defect to enhance the prediction accuracy. The results demonstrate that the proposed model can predict the multiaxial fatigue life of 3D-printed BMG with satisfactory accuracy.

增材制造解锁了具有复杂几何形状的大块金属玻璃（BMG）组件的近净形状生产。然而，它们在多轴循环载荷下的耐久性在很大程度上仍未被探索和了解。研究了选择性激光熔化zr59 .3 cu28 .8 nb1.5 . al10.4 zr基BMG的多轴疲劳行为。在多轴疲劳试验中，选取17个孔隙率约为0.46%的试件进行应力控制循环加载，包括比例加载路径和非比例加载路径。利用扫描电镜对断口形貌和多轴疲劳机理进行了系统分析。为了评估3d打印bmg的疲劳寿命，同时考虑到制造引起的缺陷，我们使用包含单孔缺陷的代表性体积元（RVE）模型进行了基于缺陷的计算模拟。通过参数化研究考察了孔隙位置对多轴疲劳寿命性能的影响。在有限元模拟结果的基础上，提出了一种改进的非局部Dang Van准则来预测多轴疲劳寿命。在临界平面模型中，根据缺陷附近临界位置的主应力引入非比例修正系数，提高了预测精度。结果表明，该模型能较好地预测3d打印BMG的多轴疲劳寿命。

{"title":"Defect-based multiaxial fatigue life assessment of 3D-printed bulk metallic glasses","authors":"Songyun Ma , Hongshi Ruan , Jianye Shi , Cécile Chaxel , Shuai Wei , Moritz Stolpe , Peilei Zhang , Yangjian Xu , Bernd Markert","doi":"10.1016/j.ijfatigue.2026.109528","DOIUrl":"10.1016/j.ijfatigue.2026.109528","url":null,"abstract":"<div><div>Additive manufacturing unlocks near-net-shape production of bulk metallic glass (BMG) components with complex geometries. Nevertheless, their durability under multiaxial cyclic loadings remains largely unexplored and poorly understood. In this work, the multiaxial fatigue behaviour of selective laser melting (SLM) fabricated Zr-based BMG with composition <span><math><mrow><msub><mrow><mi>Zr</mi></mrow><mrow><mn>59</mn><mo>.</mo><mn>3</mn></mrow></msub><msub><mrow><mi>Cu</mi></mrow><mrow><mn>28</mn><mo>.</mo><mn>8</mn></mrow></msub><msub><mrow><mi>Nb</mi></mrow><mrow><mn>1</mn><mo>.</mo><mn>5</mn></mrow></msub><msub><mrow><mi>Al</mi></mrow><mrow><mn>10</mn><mo>.</mo><mn>4</mn></mrow></msub></mrow></math></span> is investigated. In multiaxial fatigue experiments, 17 specimens with approximately 0.46% porosity were subjected to stress-controlled cyclic loadings, including both proportional and non-proportional loading paths. The fracture morphology and multiaxial fatigue mechanisms were systematically analysed using SEM micrographs. To evaluate the fatigue life of 3D-printed BMGs while accounting for manufacturing-induced defects, we conducted defect-based computational simulations using representative volume element (RVE) models incorporating a single pore defect. Parametric studies were carried out to examine the influence of pore location on multiaxial fatigue life performance. Based on the FEM simulation results, a modified non-local Dang Van criterion is proposed for predicting the multiaxial fatigue life. In the critical plane model, a non-proportional correction coefficient is introduced based on the principal stress at the critical location in the vicinity of the defect to enhance the prediction accuracy. The results demonstrate that the proposed model can predict the multiaxial fatigue life of 3D-printed BMG with satisfactory accuracy.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109528"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072459","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}

引用次数: 0

Effect of fatigue-initiating defect area measurement on defect size distributions and fatigue assessment of ductile cast iron 疲劳启动缺陷面积测量对球墨铸铁缺陷尺寸分布及疲劳评定的影响

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-19 DOI: 10.1016/j.ijfatigue.2026.109499

Max Ahlqvist , Viktor Norman , Daniel Leidermark

Numerous methods have been suggested to quantify fatigue-initiating defect size on fracture surfaces, the most prevalent are based on the Murakami–Endo

\sqrt{a r e a}

-parameter. However, there is an ambiguity in how to systemically determine defect areas. For instance, in literature on high-cycle fatigue of ductile cast irons the several different methods have been suggested: (i) the traced contour, (ii) the convex hull, (iii) the minimum circumscribed circle, and (iv) the minimum bounding rectangle. This work focuses on comparing and evaluating these methods by assessing the fatigue-initiating defect area distributions, and the influence on fatigue assessment using the

\sqrt{a r e a}

-parameter. To this end, very high cycle fatigue data on ductile cast irons with different microstructures is used, where complex shaped defects are the root-cause for fatigue failures. It is shown that there is a significant difference in the area distributions, originating from the applied area measurement method. In addition, to enable and include fatigue assessment of high strength ausferritic ductile irons, two improved Murakami–Endo type models are proposed, which show satisfactory prediction capabilities over a wide range of ductile cast iron microstructures. To further evaluate the different area measurement methods, the suggested models are validated against ductile cast iron high-cycle fatigue data from literature having artificial defects and notches. Finally, it is concluded that the traced contour defect measurement method yields the best agreement between artificial and natural defects, and overall, the least prediction errors.

人们提出了许多方法来量化断口表面的疲劳缺陷尺寸，最常用的是基于Murakami-Endo区域参数。然而，在如何系统地确定缺陷区域方面存在歧义。例如，在关于球墨铸铁高周疲劳的文献中，提出了几种不同的方法：(i)追踪轮廓，（ii）凸壳，（iii）最小外缘圆，（iv）最小边界矩形。本文通过评估疲劳启动缺陷的面积分布，以及使用面积参数对疲劳评估的影响，对这些方法进行了比较和评价。为此，使用了具有不同显微组织的球墨铸铁的高周疲劳数据，其中复杂形状的缺陷是疲劳失效的根本原因。结果表明，由于采用的面积测量方法不同，区域分布存在显著差异。此外，为了对高强度奥氏体球墨铸铁进行疲劳评估，提出了两种改进的Murakami-Endo模型，这两种模型在广泛的球墨铸铁显微组织范围内显示出令人满意的预测能力。为了进一步评估不同的面积测量方法，建议的模型与文献中含有人工缺陷和缺口的球墨铸铁高周疲劳数据进行了验证。最后，得出了跟踪轮廓缺陷测量方法在人工缺陷和自然缺陷之间的一致性最好，总体上预测误差最小的结论。

{"title":"Effect of fatigue-initiating defect area measurement on defect size distributions and fatigue assessment of ductile cast iron","authors":"Max Ahlqvist , Viktor Norman , Daniel Leidermark","doi":"10.1016/j.ijfatigue.2026.109499","DOIUrl":"10.1016/j.ijfatigue.2026.109499","url":null,"abstract":"<div><div>Numerous methods have been suggested to quantify fatigue-initiating defect size on fracture surfaces, the most prevalent are based on the Murakami–Endo <span><math><msqrt><mrow><mi>a</mi><mi>r</mi><mi>e</mi><mi>a</mi></mrow></msqrt></math></span>-parameter. However, there is an ambiguity in how to systemically determine defect areas. For instance, in literature on high-cycle fatigue of ductile cast irons the several different methods have been suggested: (i) the traced contour, (ii) the convex hull, (iii) the minimum circumscribed circle, and (iv) the minimum bounding rectangle. This work focuses on comparing and evaluating these methods by assessing the fatigue-initiating defect area distributions, and the influence on fatigue assessment using the <span><math><msqrt><mrow><mi>a</mi><mi>r</mi><mi>e</mi><mi>a</mi></mrow></msqrt></math></span>-parameter. To this end, very high cycle fatigue data on ductile cast irons with different microstructures is used, where complex shaped defects are the root-cause for fatigue failures. It is shown that there is a significant difference in the area distributions, originating from the applied area measurement method. In addition, to enable and include fatigue assessment of high strength ausferritic ductile irons, two improved Murakami–Endo type models are proposed, which show satisfactory prediction capabilities over a wide range of ductile cast iron microstructures. To further evaluate the different area measurement methods, the suggested models are validated against ductile cast iron high-cycle fatigue data from literature having artificial defects and notches. Finally, it is concluded that the traced contour defect measurement method yields the best agreement between artificial and natural defects, and overall, the least prediction errors.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109499"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000570","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}

引用次数: 0

Fatigue resistance of stainless steel bolts under tension 不锈钢螺栓在拉力作用下的抗疲劳性能

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-23 DOI: 10.1016/j.ijfatigue.2026.109515

Lukas Ehrhardt, Natalie Stranghöner

Bolted connections made of stainless steel are increasingly used in cyclic loading applications. The design rules according to the current version of the first generation of EN 1993-1-9 were historically developed for carbon steel bolts and apply equally to stainless steel bolts, although the material properties of carbon and stainless steel bolts differ significantly. Furthermore, the fatigue resistance of stainless steel bolts is almost unknown. In the draft of the second generation of EN 1993-1-9, FprEN 1993-1-9, design rules for stainless steel bolts are not specified anymore.

For this reason, fatigue tests under constant amplitude loading under tension were conducted with bolts M16, M20, M24 and M36 according to EN ISO 4014/4017 made of austenitic stainless steel (A2 and A4) and austenitic-ferritic (duplex) stainless steel (D4, D6 and D8) with property classes 70, 80 and 100. In total, 175 fatigue tests under constant amplitude loading under tension were performed in accordance with DIN 969.

The fatigue tests showed that the investigated stainless steel bolts achieve higher fatigue resistances than specified by the detail category according to EN 1993-1-9, so that the specified fatigue resistance is conservative. Based on the results, modifications of the detail categories for stainless steel bolts and rods are proposed, which allow a more economical design. The results of this investigation have already been proposed for an early amendment to FprEN 1993-1-9. This paper provides background information of the proposed modifications.

不锈钢螺栓连接越来越多地用于循环加载应用。根据第一代EN 1993-1-9当前版本的设计规则，历史上是为碳钢螺栓开发的，同样适用于不锈钢螺栓，尽管碳螺栓和不锈钢螺栓的材料性能有很大不同。此外，不锈钢螺栓的抗疲劳性能几乎是未知的。在第二代en1993 -1-9、FprEN 1993-1-9的草案中，不再规定不锈钢螺栓的设计规则。为此，根据EN ISO 4014/4017标准，用性能等级为70、80和100的奥氏体不锈钢（A2和A4）和奥氏体-铁素体（双相）不锈钢（D4、D6和D8）制作的螺栓M16、M20、M24和M36进行了恒幅载荷下的拉伸疲劳试验。根据DIN 969，总共进行了175次恒幅载荷下的拉伸疲劳试验。疲劳试验表明，所研究的不锈钢螺栓的抗疲劳性能高于en1993 -1-9细部分类规定的抗疲劳性能，因此规定的抗疲劳性能是保守的。在此基础上，提出了对不锈钢螺栓和杆的细部分类进行修改的建议，使设计更加经济。这项调查的结果已被提议尽早修订FprEN 1993-1-9。本文提供了拟议修改的背景资料。

{"title":"Fatigue resistance of stainless steel bolts under tension","authors":"Lukas Ehrhardt, Natalie Stranghöner","doi":"10.1016/j.ijfatigue.2026.109515","DOIUrl":"10.1016/j.ijfatigue.2026.109515","url":null,"abstract":"<div><div>Bolted connections made of stainless steel are increasingly used in cyclic loading applications. The design rules according to the current version of the first generation of EN 1993-1-9 were historically developed for carbon steel bolts and apply equally to stainless steel bolts, although the material properties of carbon and stainless steel bolts differ significantly. Furthermore, the fatigue resistance of stainless steel bolts is almost unknown. In the draft of the second generation of EN 1993-1-9, FprEN 1993-1-9, design rules for stainless steel bolts are not specified anymore.</div><div>For this reason, fatigue tests under constant amplitude loading under tension were conducted with bolts M16, M20, M24 and M36 according to EN ISO 4014/4017 made of austenitic stainless steel (A2 and A4) and austenitic-ferritic (duplex) stainless steel (D4, D6 and D8) with property classes 70, 80 and 100. In total, 175 fatigue tests under constant amplitude loading under tension were performed in accordance with DIN 969.</div><div>The fatigue tests showed that the investigated stainless steel bolts achieve higher fatigue resistances than specified by the detail category according to EN 1993-1-9, so that the specified fatigue resistance is conservative. Based on the results, modifications of the detail categories for stainless steel bolts and rods are proposed, which allow a more economical design. The results of this investigation have already been proposed for an early amendment to FprEN 1993-1-9. This paper provides background information of the proposed modifications.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109515"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033258","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}

引用次数: 0

Vision-driven and Bayesian-enhanced YOLO-PINN hybrid framework for crack propagation and fatigue life prediction 视觉驱动和贝叶斯增强的ylo - pinn混合框架用于裂纹扩展和疲劳寿命预测

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-22 DOI: 10.1016/j.ijfatigue.2026.109511

Zhizhuo Zhang , Mengchuang Zhang , Yan Li , Enrico Zappino , Zhiping Yin

Accurate detection and prediction of crack propagation are critical for maintaining the integrity and extending the service life of aerospace structures. We present a novel hybrid framework that integrates deep learning-based computer vision with physics-informed modeling to improve crack-growth forecasting. First, an enhanced You Only Look Once (YOLO) object-detection and segmentation network precisely extracts crack morphology from inspection images. These measurements feed into physics-informed neural network (PINN) that embeds the governing fracture mechanics equations to predict temporal growth trajectories. To maximize predictive accuracy, a Bayesian correlation scheme iteratively selects and refines the training set, ensuring inclusion of the most informative imaging samples. This feedback loop continuously enhances the model’s adaptability and reliability. Validation on benchmark datasets demonstrates that our hybrid approach significantly outperforms purely data-driven or purely physics-based methods, offering robust, real-time structural health monitoring. The proposed methodology provides a novel approach for predictive maintenance and lifecycle management of critical aerospace components.

裂纹扩展的准确检测和预测对于保持航天结构的完整性和延长其使用寿命至关重要。我们提出了一种新的混合框架，将基于深度学习的计算机视觉与物理信息建模相结合，以改进裂缝增长预测。首先，一个增强的You Only Look Once （YOLO）目标检测和分割网络精确地从检测图像中提取裂纹形态。这些测量结果输入到物理信息神经网络（PINN）中，该网络嵌入了控制断裂力学方程，以预测时间生长轨迹。为了最大限度地提高预测精度，贝叶斯相关方案迭代地选择和改进训练集，确保包含最具信息量的成像样本。这种反馈回路不断增强了模型的适应性和可靠性。在基准数据集上的验证表明，我们的混合方法明显优于纯粹的数据驱动或纯粹基于物理的方法，提供强大的实时结构健康监测。该方法为航空航天关键部件的预测性维护和生命周期管理提供了一种新的方法。

{"title":"Vision-driven and Bayesian-enhanced YOLO-PINN hybrid framework for crack propagation and fatigue life prediction","authors":"Zhizhuo Zhang , Mengchuang Zhang , Yan Li , Enrico Zappino , Zhiping Yin","doi":"10.1016/j.ijfatigue.2026.109511","DOIUrl":"10.1016/j.ijfatigue.2026.109511","url":null,"abstract":"<div><div>Accurate detection and prediction of crack propagation are critical for maintaining the integrity and extending the service life of aerospace structures. We present a novel hybrid framework that integrates deep learning-based computer vision with physics-informed modeling to improve crack-growth forecasting. First, an enhanced You Only Look Once (YOLO) object-detection and segmentation network precisely extracts crack morphology from inspection images. These measurements feed into physics-informed neural network (PINN) that embeds the governing fracture mechanics equations to predict temporal growth trajectories. To maximize predictive accuracy, a Bayesian correlation scheme iteratively selects and refines the training set, ensuring inclusion of the most informative imaging samples. This feedback loop continuously enhances the model’s adaptability and reliability. Validation on benchmark datasets demonstrates that our hybrid approach significantly outperforms purely data-driven or purely physics-based methods, offering robust, real-time structural health monitoring. The proposed methodology provides a novel approach for predictive maintenance and lifecycle management of critical aerospace components.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109511"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033259","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}

引用次数: 0

Blunt and sharp notches: Revisiting the limit notch radius via the averaged SED method and validating it against a wide fatigue strength reduction database 钝口和尖口：通过平均SED方法重新访问极限缺口半径，并根据广泛的疲劳强度降低数据库进行验证

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-19 DOI: 10.1016/j.ijfatigue.2026.109496

Pietro Foti , Michele Zappalorto , Filippo Berto

When designing mechanical components, their functional requirements often lead to geometrical discontinuities with severe stress concentrations and gradients. These discontinuities, known as notches, can markedly reduce the structural reliability and fatigue strength of components. Depending on the notch severity, conventional point-based approaches may significantly overestimate their detrimental effects on fatigue behaviour. Notches are generally classified as blunt or sharp with the fatigue behaviour of the sharp ones not accurately captured by point-based approaches. Numerous studies have attempted to define the transition between these two behaviour and to develop design methodologies capable of consistently addressing both. Among these, the averaged Strain Energy Density (SED) method has demonstrated high accuracy and robustness for both blunt and sharp notches. In this work, the SED method is employed to identify a limiting condition, expressed through a limit notch radius,

ρ_{limit}

, that distinguishes between blunt and sharp notches. This condition is investigated through numerical simulations and validated against an extensive fatigue database from the literature. Defining the limit condition as a notch radius simplifies components design and may also serve as guideline for determining the required notches tolerances. Finally, a methodology is proposed for fatigue-oriented material selection, coupling bulk material properties, component geometry and notch sensitivity. Indeed, in fatigue design, the highest-performing component is not necessarily obtained using the material with the highest intrinsic fatigue strength. For sharp notches, materials with lower intrinsic fatigue strength, but reduced notch sensitivity, can indeed yield superior fatigue performance. The methodology can be readily extended to lightweight design applications.

在设计机械部件时，其功能要求常常导致具有严重应力集中和梯度的几何不连续。这些被称为缺口的不连续性会显著降低构件的结构可靠性和疲劳强度。根据缺口的严重程度，传统的基于点的方法可能大大高估了它们对疲劳行为的有害影响。缺口一般分为钝的或锐的，锐的疲劳行为不能被基于点的方法准确捕获。许多研究试图定义这两种行为之间的转换，并开发能够始终解决这两种行为的设计方法。其中，平均应变能密度（SED）方法对钝切口和锐切口均具有较高的精度和鲁棒性。在这项工作中，SED方法被用来识别一个极限条件，通过一个极限缺口半径表示，ρ极限，区分钝和锋利的缺口。这种情况通过数值模拟进行了研究，并通过文献中广泛的疲劳数据库进行了验证。将极限条件定义为缺口半径可以简化零件的设计，也可以作为确定所需缺口公差的指南。最后，提出了一种面向疲劳的材料选择、耦合体材料特性、部件几何形状和缺口灵敏度的方法。事实上，在疲劳设计中，性能最高的部件不一定是使用具有最高固有疲劳强度的材料获得的。对于锋利的缺口，材料具有较低的固有疲劳强度，但降低缺口灵敏度，确实可以产生良好的疲劳性能。该方法可以很容易地扩展到轻量级设计应用程序。

{"title":"Blunt and sharp notches: Revisiting the limit notch radius via the averaged SED method and validating it against a wide fatigue strength reduction database","authors":"Pietro Foti , Michele Zappalorto , Filippo Berto","doi":"10.1016/j.ijfatigue.2026.109496","DOIUrl":"10.1016/j.ijfatigue.2026.109496","url":null,"abstract":"<div><div>When designing mechanical components, their functional requirements often lead to geometrical discontinuities with severe stress concentrations and gradients. These discontinuities, known as notches, can markedly reduce the structural reliability and fatigue strength of components. Depending on the notch severity, conventional point-based approaches may significantly overestimate their detrimental effects on fatigue behaviour. Notches are generally classified as blunt or sharp with the fatigue behaviour of the sharp ones not accurately captured by point-based approaches. Numerous studies have attempted to define the transition between these two behaviour and to develop design methodologies capable of consistently addressing both. Among these, the averaged Strain Energy Density (SED) method has demonstrated high accuracy and robustness for both blunt and sharp notches. In this work, the SED method is employed to identify a limiting condition, expressed through a limit notch radius, <span><math><msub><mi>ρ</mi><mrow><mi>limit</mi></mrow></msub></math></span>, that distinguishes between blunt and sharp notches. This condition is investigated through numerical simulations and validated against an extensive fatigue database from the literature. Defining the limit condition as a notch radius simplifies components design and may also serve as guideline for determining the required notches tolerances. Finally, a methodology is proposed for fatigue-oriented material selection, coupling bulk material properties, component geometry and notch sensitivity. Indeed, in fatigue design, the highest-performing component is not necessarily obtained using the material with the highest intrinsic fatigue strength. For sharp notches, materials with lower intrinsic fatigue strength, but reduced notch sensitivity, can indeed yield superior fatigue performance. The methodology can be readily extended to lightweight design applications.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109496"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000568","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}

引用次数: 0

From stress field to multiaxial fatigue life: A novel physics-guided neural network framework accounting for stress ratio, phase angle, and biaxiality ratio 从应力场到多轴疲劳寿命：一种新的物理导向神经网络框架，用于计算应力比、相位角和双轴比

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-13 DOI: 10.1016/j.ijfatigue.2026.109497

Amir Mohammad Mirzaei

Predicting the fatigue life under multiaxial loading is challenging because failure is governed by local stress fields and evolution of the stress state. The central idea of this study is to represent the geometric effect (including plain and notched configurations) by the spatial distributions of the three principal stresses in the potential region of failure, discretised over a set of nodes. Sampling these fields over one load cycle captures the loading history (stress ratio, biaxiality ratio, and phase angle) for constant-amplitude multiaxial loading, without introducing any additional ad hoc or phenomenological scalar damage parameter. To encode this loading history, a lightweight temporal Conv1D encoder is followed by a compact fully-connected regression head. The framework is validated on EN-GJS-600-3 using leave-one-case-out splits over 18 geometry–loading cases covering multiple geometries, axial, torsional, and multiaxial loading, three stress ratios, two biaxiality ratios, and three phase angles. Across this broad set, the model achieves R² = 0.70, while adding the nominal metadata increases the prediction accuracy to R² = 0.75. Compared with classical critical-plane benchmarks (SWT and FS), the proposed framework achieves higher accuracy and remains applicable to both plain and notched specimens, whereas critical-plane criteria degrade strongly when plain data are included (due to differences in the dominant failure mechanisms). Sensitivity analyses confirmed robustness to reasonable choices of spatial and temporal discretisation. Gradient-based saliency illustrates mechanistic insights: spatial importance concentrates at the notch tip, and temporal importance is dominated by the first principal-stress, consistent with tensile crack-opening and with SWT, which outperforms the shear-driven FS criterion.

多轴载荷下的疲劳寿命预测具有挑战性，因为失效受局部应力场和应力状态演变的控制。本研究的中心思想是通过在一组节点上离散的潜在破坏区域中的三个主应力的空间分布来表示几何效应（包括平原和缺口结构）。在一个加载周期内对这些场进行采样，可以捕获恒幅多轴加载的加载历史（应力比、双轴比和相位角），而无需引入任何额外的特殊或现象标量损伤参数。为了对这个加载历史进行编码，一个轻量级的临时Conv1D编码器后面跟着一个紧凑的全连接回归头。该框架在EN-GJS-600-3上进行了18种几何载荷工况的验证，包括多种几何载荷、轴向载荷、扭转载荷和多轴载荷、三种应力比、两种双轴比和三种相位角。在这个广泛的集合中，模型达到R2 = 0.70，而添加标称元数据将预测精度提高到R2 = 0.75。与经典的临界平面基准（SWT和FS）相比，所提出的框架具有更高的精度，并且仍然适用于普通和缺口样本，而当包含普通数据时，临界平面标准会严重退化（由于主要破坏机制的差异）。敏感性分析证实了对空间和时间离散化合理选择的鲁棒性。基于梯度的显著性说明了机理见解：空间重要性集中在缺口尖端，时间重要性由第一主应力主导，与拉伸裂缝张开和SWT一致，优于剪切驱动的FS准则。

{"title":"From stress field to multiaxial fatigue life: A novel physics-guided neural network framework accounting for stress ratio, phase angle, and biaxiality ratio","authors":"Amir Mohammad Mirzaei","doi":"10.1016/j.ijfatigue.2026.109497","DOIUrl":"10.1016/j.ijfatigue.2026.109497","url":null,"abstract":"<div><div>Predicting the fatigue life under multiaxial loading is challenging because failure is governed by local stress fields and evolution of the stress state. The central idea of this study is to represent the geometric effect (including plain and notched configurations) by the spatial distributions of the three principal stresses in the potential region of failure, discretised over a set of nodes. Sampling these fields over one load cycle captures the loading history (stress ratio, biaxiality ratio, and phase angle) for constant-amplitude multiaxial loading, without introducing any additional ad hoc or phenomenological scalar damage parameter. To encode this loading history, a lightweight temporal Conv1D encoder is followed by a compact fully-connected regression head. The framework is validated on EN-GJS-600-3 using leave-one-case-out splits over 18 geometry–loading cases covering multiple geometries, axial, torsional, and multiaxial loading, three stress ratios, two biaxiality ratios, and three phase angles. Across this broad set, the model achieves <em>R</em><sup>2</sup> = 0.70, while adding the nominal metadata increases the prediction accuracy to <em>R</em><sup>2</sup> = 0.75. Compared with classical critical-plane benchmarks (SWT and FS), the proposed framework achieves higher accuracy and remains applicable to both plain and notched specimens, whereas critical-plane criteria degrade strongly when plain data are included (due to differences in the dominant failure mechanisms). Sensitivity analyses confirmed robustness to reasonable choices of spatial and temporal discretisation. Gradient-based saliency illustrates mechanistic insights: spatial importance concentrates at the notch tip, and temporal importance is dominated by the first principal-stress, consistent with tensile crack-opening and with SWT, which outperforms the shear-driven FS criterion.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109497"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962542","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}

引用次数: 0

Understanding the bi-modal fatigue behavior of the case-hardened M50NiL steel 了解淬火M50NiL钢的双模态疲劳行为

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-16 DOI: 10.1016/j.ijfatigue.2026.109495

Aniclelson Raony Alves de Moura , Franck Morel , Etienne Pessard , Daniel Bellett , Louis Augustins , Damien Herisson

The gears used in aircraft engines are typically made from high-strength steels reinforced by thermochemical treatments (TCT). These treatments increase surface fatigue strength through microstructural modifications, enhancing hardness and adding compressive residual stresses. In some cases, the combination of material, TCT, and applied stress can lead to a bi-modal fatigue behavior, notably in failures at the gear tooth root. This work investigates the bi-modal fatigue response of M50NiL case-hardened steel by characterizing and analyzing crack initiation mechanisms to propose a relevant fatigue modeling approach. A comprehensive experimental fatigue test campaign was carried out on notched specimens under plane bending and on gear specimens using a Single Tooth Bending Fatigue (STBF) method. The resulting Wöhler diagram shows significant scatter in fatigue life for several stress levels, suggesting a bi-modal behavior with two distinct populations. Fractographic analyses confirmed the competition between two different crack initiation mechanisms depending on stress level and number of cycles to failure. A statistical analysis using a mixture model also indicates that a bi-modal distribution best represents the results. Accordingly, a probabilistic model is proposed to describe the bi-modal fatigue behavior from a global perspective, based on the maximum applied hot-spot surface stress for a fixed stress ratio. Finally, a complementary local stress analysis shows that the combined effect of stress and material property distributions significantly influences local maximum stress variation. Correcting for these factors reduces scatter in the bi-modal stress levels.

飞机发动机中使用的齿轮通常由高强度钢制成，经热化学处理（TCT）增强。这些处理通过改变微观组织、提高硬度和增加压残余应力来提高表面疲劳强度。在某些情况下，材料、TCT和施加应力的组合可能导致双峰疲劳行为，特别是在齿轮齿根处的失效。本文研究了M50NiL淬火钢的双模态疲劳响应，对裂纹起裂机制进行了表征和分析，提出了相应的疲劳建模方法。采用单齿弯曲疲劳法对缺口试件和齿轮试件进行了全面的平面弯曲疲劳试验。由此得出的Wöhler图显示了几种应力水平下疲劳寿命的显著分散，表明具有两个不同种群的双峰态行为。断口分析证实了两种不同的裂纹起裂机制之间的竞争，这取决于应力水平和失效循环次数。使用混合模型的统计分析也表明，双峰分布最能代表结果。因此，提出了一个基于固定应力比下热点表面最大应力的概率模型，从全局角度描述双峰疲劳行为。最后，互补的局部应力分析表明，应力和材料性能分布的共同作用对局部最大应力变化有显著影响。校正这些因素可减少双模态应力水平的分散。

{"title":"Understanding the bi-modal fatigue behavior of the case-hardened M50NiL steel","authors":"Aniclelson Raony Alves de Moura , Franck Morel , Etienne Pessard , Daniel Bellett , Louis Augustins , Damien Herisson","doi":"10.1016/j.ijfatigue.2026.109495","DOIUrl":"10.1016/j.ijfatigue.2026.109495","url":null,"abstract":"<div><div>The gears used in aircraft engines are typically made from high-strength steels reinforced by thermochemical treatments (TCT). These treatments increase surface fatigue strength through microstructural modifications, enhancing hardness and adding compressive residual stresses. In some cases, the combination of material, TCT, and applied stress can lead to a bi-modal fatigue behavior, notably in failures at the gear tooth root. This work investigates the bi-modal fatigue response of M50NiL case-hardened steel by characterizing and analyzing crack initiation mechanisms to propose a relevant fatigue modeling approach. A comprehensive experimental fatigue test campaign was carried out on notched specimens under plane bending and on gear specimens using a Single Tooth Bending Fatigue (STBF) method. The resulting Wöhler diagram shows significant scatter in fatigue life for several stress levels, suggesting a bi-modal behavior with two distinct populations. Fractographic analyses confirmed the competition between two different crack initiation mechanisms depending on stress level and number of cycles to failure. A statistical analysis using a mixture model also indicates that a bi-modal distribution best represents the results. Accordingly, a probabilistic model is proposed to describe the bi-modal fatigue behavior from a global perspective, based on the maximum applied hot-spot surface stress for a fixed stress ratio. Finally, a complementary local stress analysis shows that the combined effect of stress and material property distributions significantly influences local maximum stress variation. Correcting for these factors reduces scatter in the bi-modal stress levels.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109495"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995465","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}

引用次数: 0

Deterioration mechanism of the macroscopic properties and microstructure of concrete under low-temperature cyclic fatigue action 低温循环疲劳作用下混凝土宏观性能和微观结构劣化机理

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-14 DOI: 10.1016/j.ijfatigue.2026.109493

Liu Jin, Xiang Chen, Jieqiong Wu, Jian Yang, Xiuli Du

This study investigates the microstructural and macro-mechanical property degradation mechanisms of concrete subjected to low-temperature freeze–thaw cycles (LFC, –40 ℃ to 20 ℃) in four representative solutions (C₂H₆O₂ (ethylene glycol), H₂O, 3.5% NaCl, and 3.5% Na₂SO₄). The correlations between microstructures and macro-mechanical properties are analyzed with the aid of innovative techniques including vickers hardness, nanoindentation, etc. Results show that compared with the freeze–thaw with minimum temperature of almost –20 °C, LFC lead to more severe damage and alter the damage order as: 3.5% NaCl > 3.5% Na₂SO₄ > H₂O > C₂H₆O₂, originated from expansion effects including the water ice expansion, corrosion product expansion, and uneven expansion (or contraction) due to temperature gradients. Although the low-temperature expansion rates of 3.5% Na₂SO₄ and 3.5% NaCl solutions are lower than that of water, their damage is severe: the former involves synergistic damage from ice and ettringite expansion, while the latter is exacerbated by hysteretic low-temperature expansion and hygroscopicity of NaCl. Besides, LFC increase the porosity, the more-harmful pore proportion, porous phase, while decrease the nano-indentation elastic modulus of the cement matrix and the high-density C-S-H content with more severe damage to the cement matrix than the aggregates, leading to the concrete strength degradation. Furthermore, the strength damage is linearly correlated with the more-harmful pore proportion, vickers hardness damage, nano-indentation elastic modulus, but non-linearly related to the porosity, porous phase, and high-density C-S-H content.

研究了低温冻融循环（LFC, -40℃~ 20℃）下混凝土在四种代表性溶液（C2H6O2（乙二醇）、H2O、3.5% NaCl和3.5% Na2SO4）中的微观结构和宏观力学性能退化机理。利用维氏硬度、纳米压痕等新技术分析了合金的微观组织与宏观力学性能之间的关系。结果表明：与最低温度接近-20℃的冻融相比，LFC损伤更为严重，损伤顺序依次为：3.5% NaCl > 3.5% Na2SO4 > H2O > C2H6O2，其原因是水冰膨胀、腐蚀产物膨胀以及温度梯度引起的不均匀膨胀（或收缩）。虽然3.5% Na2SO4和3.5% NaCl溶液的低温膨胀率低于水，但其破坏程度较严重：前者是冰和钙矾石膨胀的协同破坏，后者是NaCl的滞后性低温膨胀和吸湿性加剧的破坏。此外，LFC增加了孔隙率、更有害的孔隙比例、多孔相，降低了水泥基体的纳米压痕弹性模量和高密度C-S-H含量，对水泥基体的损伤比骨料更严重，导致混凝土强度退化。强度损伤与更有害孔隙比例、维氏硬度损伤、纳米压痕弹性模量呈线性相关，而与孔隙率、多孔相和高密度C-S-H含量呈非线性相关。

{"title":"Deterioration mechanism of the macroscopic properties and microstructure of concrete under low-temperature cyclic fatigue action","authors":"Liu Jin, Xiang Chen, Jieqiong Wu, Jian Yang, Xiuli Du","doi":"10.1016/j.ijfatigue.2026.109493","DOIUrl":"10.1016/j.ijfatigue.2026.109493","url":null,"abstract":"<div><div>This study investigates the microstructural and macro-mechanical property degradation mechanisms of concrete subjected to low-temperature freeze–thaw cycles (LFC, –40 ℃ to 20 ℃) in four representative solutions (C<sub>2</sub>H<sub>6</sub>O<sub>2</sub> (ethylene glycol), H<sub>2</sub>O, 3.5% NaCl, and 3.5% Na<sub>2</sub>SO<sub>4</sub>). The correlations between microstructures and macro-mechanical properties are analyzed with the aid of innovative techniques including vickers hardness, nanoindentation, etc. Results show that compared with the freeze–thaw with minimum temperature of almost –20 °C, LFC lead to more severe damage and alter the damage order as: 3.5% NaCl > 3.5% Na<sub>2</sub>SO<sub>4</sub> > H<sub>2</sub>O > C<sub>2</sub>H<sub>6</sub>O<sub>2</sub>, originated from expansion effects including the water ice expansion, corrosion product expansion, and uneven expansion (or contraction) due to temperature gradients. Although the low-temperature expansion rates of 3.5% Na<sub>2</sub>SO<sub>4</sub> and 3.5% NaCl solutions are lower than that of water, their damage is severe: the former involves synergistic damage from ice and ettringite expansion, while the latter is exacerbated by hysteretic low-temperature expansion and hygroscopicity of NaCl. Besides, LFC increase the porosity, the more-harmful pore proportion, porous phase, while decrease the nano-indentation elastic modulus of the cement matrix and the high-density C-S-H content with more severe damage to the cement matrix than the aggregates, leading to the concrete strength degradation. Furthermore, the strength damage is linearly correlated with the more-harmful pore proportion, vickers hardness damage, nano-indentation elastic modulus, but non-linearly related to the porosity, porous phase, and high-density C-S-H content.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109493"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995471","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}

引用次数: 0

Shear fatigue life prediction method for plug welded joints based on the equivalent structural stress model 基于等效结构应力模型的塞焊接头剪切疲劳寿命预测方法

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-15 DOI: 10.1016/j.ijfatigue.2026.109500

Long Yang , Xiao An , Wenyang Shao , Guangwu Yang , Bing Yang , Tao Zhu , Zhe Zhang

Fatigue fracture often occurs in plug welded joints under shear loads, but an accurate fatigue life evaluation method for this special type of joint has not yet been proposed. Therefore, the fatigue failure behavior of plug welded joints through extensive shear fatigue tests was investigated in this study. To this end, the fatigue failure process and failure modes of plug welded joints under shear loading were obtained, and F_a–N curves were established. The investigation revealed that the overall F_a–N curve exhibited poor correlation and did not satisfy the engineering requirements. Consequently, an equivalent structural stress model that accurately captures the stress state of plug welded joints using the coupled node loads as input conditions was derived. A beam-shell finite element (FE) model that can accurately simulate the stress distribution of the plug welded joint was subsequently established to obtain the load inputs for the model. The forces and moments of the coupled nodes extracted from the FE model were input into the equivalent structural stress model to obtain the equivalent structural stress σ_s of the plug welded joint. Finally, S_s–N and P–S_s–N curves normalized for different F_a–N curves were developed, and a shear fatigue life prediction method for plug welded joints based on the equivalent structural stress method was established. The accuracy of this method was verified through random vibration fatigue test. The findings of this study provide a reference for the structural design and life prediction of plug welded joints.

塞焊接头在剪切载荷作用下经常发生疲劳断裂，但目前还没有针对这种特殊类型的接头提出准确的疲劳寿命评估方法。因此，本研究通过广泛的剪切疲劳试验对塞焊接头的疲劳破坏行为进行了研究。为此，获得了塞焊接头在剪切载荷作用下的疲劳破坏过程和破坏模式，并建立了Fa-N曲线。调查发现，总体Fa-N曲线相关性较差，不满足工程要求。在此基础上，建立了以耦合节点荷载为输入条件的等效结构应力模型，该模型能准确地捕捉塞焊接头的应力状态。建立了能准确模拟塞焊接头应力分布的梁-壳有限元模型，得到了模型的载荷输入。将有限元模型中提取的耦合节点的力和弯矩输入到等效结构应力模型中，得到塞焊接头的等效结构应力σs。最后，建立了不同Fa-N曲线归一化后的Ss-N和P-Ss-N曲线，建立了基于等效结构应力法的塞焊接头剪切疲劳寿命预测方法。通过随机振动疲劳试验验证了该方法的准确性。研究结果可为塞焊接头的结构设计和寿命预测提供参考。

{"title":"Shear fatigue life prediction method for plug welded joints based on the equivalent structural stress model","authors":"Long Yang , Xiao An , Wenyang Shao , Guangwu Yang , Bing Yang , Tao Zhu , Zhe Zhang","doi":"10.1016/j.ijfatigue.2026.109500","DOIUrl":"10.1016/j.ijfatigue.2026.109500","url":null,"abstract":"<div><div>Fatigue fracture often occurs in plug welded joints under shear loads, but an accurate fatigue life evaluation method for this special type of joint has not yet been proposed. Therefore, the fatigue failure behavior of plug welded joints through extensive shear fatigue tests was investigated in this study. To this end, the fatigue failure process and failure modes of plug welded joints under shear loading were obtained, and <em>F</em><sub>a</sub>–<em>N</em> curves were established. The investigation revealed that the overall <em>F</em><sub>a</sub>–<em>N</em> curve exhibited poor correlation and did not satisfy the engineering requirements. Consequently, an equivalent structural stress model that accurately captures the stress state of plug welded joints using the coupled node loads as input conditions was derived. A beam-shell finite element (FE) model that can accurately simulate the stress distribution of the plug welded joint was subsequently established to obtain the load inputs for the model. The forces and moments of the coupled nodes extracted from the FE model were input into the equivalent structural stress model to obtain the equivalent structural stress <em>σ</em><sub>s</sub> of the plug welded joint. Finally, <em>S</em><sub>s</sub>–<em>N</em> and <em>P</em>–<em>S</em><sub>s</sub>–<em>N</em> curves normalized for different <em>F</em><sub>a</sub>–<em>N</em> curves were developed, and a shear fatigue life prediction method for plug welded joints based on the equivalent structural stress method was established. The accuracy of this method was verified through random vibration fatigue test. The findings of this study provide a reference for the structural design and life prediction of plug welded joints.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109500"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995467","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}

引用次数: 0

In-situ observations of cyclic deformation in an extruded Mg-2Nd-1Y-0.1Zr-0.1Ca alloy 挤压Mg-2Nd-1Y-0.1Zr-0.1Ca合金循环变形的原位观察

IF 6.8 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2026-06-01 Epub Date: 2026-01-18 DOI: 10.1016/j.ijfatigue.2026.109489

Arianna Mena , Jiashi Miao , Daniel Veghte , Bruce Williams , Aeriel D. Murphy-Leonard

In this study, the evolution of deformation mechanisms during cyclic loading in an extruded, solution-treated Mg–2Nd–1Y–0.1Zr–0.1Ca alloy was investigated using a combination of in-situ loading, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and focused ion beam (FIB) nanofabrication. The initial microstructure exhibited a crystallographic texture where the c-axis were orie. Flat, rectangular dog-bone specimens were subjected to load-controlled, fully reversed fatigue for 50 cycles, during which the same region was sequentially mapped to track microstructural changes. After 10 cycles of loading deformation twins were observed. During tensile reloading detwinning or narrowing of those twinned regions occurred. After 20 cycles, detwinning ceased and residual twins remained in the material. SEM imaging revealed numerous surface slip traces after cyclic loading. EBSD-assisted slip trace analysis identified the activation of prismatic < a > and pyramidal < c + a > slip systems during low-cycle fatigue. Site-specific scanning transmission electron microscopy (STEM) further revealed that deformation was also accommodated by basal < a > slip and the dissociation of < c + a > dislocations. Center-of-symmetry (COS) analysis confirmed that the dissociation of < c + a > dislocations resulted in the formation of I₁ intrinsic stacking faults after cyclic loading. These findings provide new insights into the complex interplay of dislocation mechanisms governing fatigue deformation in rare-earth-containing Mg alloys.

本研究采用原位加载、扫描电子显微镜（SEM）、电子背散射衍射（EBSD）和聚焦离子束（FIB）纳米加工相结合的方法，研究了挤压、固溶处理Mg-2Nd-1Y-0.1Zr-0.1Ca合金在循环加载过程中的变形机制演变。初始微观结构表现为c轴偏纵的晶体织构。扁平的矩形狗骨试件经受载荷控制的完全反向疲劳50次，在此期间，同一区域被依次绘制以跟踪微观结构变化。在10次循环加载后，观察到变形孪晶。在拉伸再加载过程中，孪晶区域发生脱孪或缩窄。20次循环后，脱孪生停止，材料中仍有残留的孪晶。扫描电镜成像显示了循环加载后大量的表面滑动痕迹。EBSD-assisted滑痕量分析确定激活棱镜 & lt;  比; 和锥体 & lt; c +  祝辞 滑移系统在低循环疲劳。特定站点扫描透射电子显微镜(STEM)进一步显示,变形也适应了基底 & lt;  比; 滑的离解 & lt; c +  祝辞 混乱。对称中心（COS）分析证实，循环加载后， <； c + a >； 位错的解离导致I1本征层错的形成。这些发现为研究控制稀土镁合金疲劳变形的位错机制的复杂相互作用提供了新的见解。

{"title":"In-situ observations of cyclic deformation in an extruded Mg-2Nd-1Y-0.1Zr-0.1Ca alloy","authors":"Arianna Mena , Jiashi Miao , Daniel Veghte , Bruce Williams , Aeriel D. Murphy-Leonard","doi":"10.1016/j.ijfatigue.2026.109489","DOIUrl":"10.1016/j.ijfatigue.2026.109489","url":null,"abstract":"<div><div>In this study, the evolution of deformation mechanisms during cyclic loading in an extruded, solution-treated Mg–2Nd–1Y–0.1Zr–0.1Ca alloy was investigated using a combination of in-situ loading, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and focused ion beam (FIB) nanofabrication. The initial microstructure exhibited a crystallographic texture where the c-axis were orie. Flat, rectangular dog-bone specimens were subjected to load-controlled, fully reversed fatigue for 50 cycles, during which the same region was sequentially mapped to track microstructural changes. After 10 cycles of loading deformation twins were observed. During tensile reloading detwinning or narrowing of those twinned regions occurred. After 20 cycles, detwinning ceased and residual twins remained in the material. SEM imaging revealed numerous surface slip traces after cyclic loading. EBSD-assisted slip trace analysis identified the activation of prismatic < a > and pyramidal < c + a > slip systems during low-cycle fatigue. Site-specific scanning transmission electron microscopy (STEM) further revealed that deformation was also accommodated by basal < a > slip and the dissociation of < c + a > dislocations. Center-of-symmetry (COS) analysis confirmed that the dissociation of < c + a > dislocations resulted in the formation of I<sub>1</sub> intrinsic stacking faults after cyclic loading. These findings provide new insights into the complex interplay of dislocation mechanisms governing fatigue deformation in rare-earth-containing Mg alloys.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109489"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995479","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}

引用次数: 0