International Journal of Fatigue最新文献_第10页

Predicting fatigue slip and fatigue life of FRP rebar-concrete bonds using tree-based and theory-informed learning models 利用基于树和理论的学习模型预测FRP钢筋-混凝土粘结的疲劳滑移和疲劳寿命

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-12 DOI: 10.1016/j.ijfatigue.2025.108816

Yiliyaer Tuerxunmaimaiti , Xiao-Ling Zhao , Daxu Zhang , Qi Zhao , Pei-Fu Zhang , Xuan Zhao , Mudassir Iqbal

Bond fatigue failure correlates with the increase in fatigue slip, influenced by the interfacial bonding properties of fibre-reinforced polymer (FRP) rebar and concrete under fatigue loading. Fatigue slip is a crucial indicator for estimating fatigue bond life. In this study, a comprehensive fatigue-slip dataset comprising 1,140 test results from published literatures was collected to develop predictive models using two tree-based learning algorithms: Random Forest (RF), and eXtreme Gradient Boosting (XGBoost). The dataset was categorized into 11 input parameters, including concrete properties, FRP rebar characteristics, and fatigue load conditions. To understand the influence of each parameter on fatigue slip and to identify the dominant bonding mechanisms, SHAP (SHapley Additive exPlanations) analysis was carried out. The analysis identified the top five contributing parameters, which were then used to derive a third-order polynomial fatigue-slip formula. Additionally, a theory-informed learning model was employed to predict fatigue slip by combining the shear-lag model and XGBoost model. The study further proposed a method for predicting the fatigue bond life based on these fatigue-slip prediction models, providing a unique insight into fatigue evaluation. The results demonstrated that the theory-informed learning model achieved better prediction accuracy for both fatigue slip and fatigue life.

疲劳荷载作用下，FRP筋与混凝土的界面粘结性能影响着粘结层的疲劳滑移量的增加。疲劳滑移是估计疲劳结合寿命的重要指标。在这项研究中，收集了一个综合的疲劳滑移数据集，其中包括来自已发表文献的1,140个测试结果，并使用两种基于树的学习算法：随机森林（RF）和极端梯度增强（XGBoost）建立预测模型。该数据集分为11个输入参数，包括混凝土性能、FRP钢筋特性和疲劳载荷条件。为了了解各个参数对疲劳滑移的影响，并确定主要的粘接机制，进行了SHapley加性解释（SHapley Additive explanation）分析。分析确定了影响最大的五个参数，然后使用这些参数推导出三阶多项式疲劳滑移公式。此外，结合剪切滞后模型和XGBoost模型，采用基于理论的学习模型预测疲劳滑移。该研究进一步提出了一种基于这些疲劳滑移预测模型的疲劳结合寿命预测方法，为疲劳评估提供了独特的见解。结果表明，基于理论的学习模型对疲劳滑移和疲劳寿命均具有较好的预测精度。

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引用次数: 0

Experimental study on long-term fatigue behavior of piezoelectric energy harvesters under high and low-frequency vibration excitation

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-12 DOI: 10.1016/j.ijfatigue.2025.108817

Ping Yang , Ahmad Zhafran Ahmad Mazlan

The strain distribution along the cantilever piezoelectric energy harvester (PEH) beam is nonuniform, which would induce fatigue damage at the root of the cantilever in the long run, and cause failure in the piezoelectric material. In this study, fatigue vibration experiments are repeated to determine and analyse fatigue characteristics and output performance changes of the improved structures under cyclic vibration with 1 m/s² acceleration at resonance frequencies of 15 Hz and 250 Hz. In the fatigue experiment, waveform distortion or large attenuation of the high-frequency PEH is not observed during 2.03 × 10⁶ cycles. It shows that the high-frequency beam structure can protect the piezoelectric patch, which is susceptible to fatigue, from mechanical cracks to improving the lifetime of the PEH. Unlike the high-frequency PEH beam, the low-frequency PEH beam underwent final failure at the middle of the piezoelectric transducer after 3.1 × 10⁵ cycles. The result indicated that high-frequency PEH exhibits better fatigue characteristics and reliability in the complex vibration environment of the drive motor, while the fatigue strength of low-frequency PEH still needs further optimization and research. This work provides a deep insight into the reliability of the designed high-low frequency beams for piezoelectric energy harvesting on driving motor system (DMS) of electric vehicles. It will provide a reference for future studies on improving the structure reliability and electric output of PEH when working on actual working conditions.

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引用次数: 0

Ausformed high-strength low-alloy steel exhibits exceptional resistance to fatigue crack-growth in high-pressure hydrogen environments 奥形高强度低合金钢在高压氢环境中表现出优异的抗疲劳裂纹扩展能力

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-10 DOI: 10.1016/j.ijfatigue.2025.108814

Timothee Redarce , Keiichiro Iwata , Yuhei Ogawa , Kaneaki Tsuzaki , Akinobu Shibata , Hisao Matsunaga

Ausformed specimens of the chromium-molybdenum steel JIS-SCM440 were subjected to fatigue tests in both air and 90 MPa hydrogen gas. The results were compared with those of non-ausformed specimens of the same material with similar tensile strengths (≈ 950 MPa and ≈ 1050 MPa). The ausformed materials demonstrated excellent resistance to hydrogen-induced acceleration of fatigue crack-growth (FCG), effectively reducing the crack propagation rate under cyclic loading in hydrogen environments compared to their non-ausformed counterparts. They maintained an acceleration ratio (i.e., relative FCG rate in hydrogen with respect to that in air) within 10 to 40 times, an order of magnitude lower than that of the non-ausformed counterparts. Despite their high strength levels (i.e., tensile strengths greater than 900 MPa), the FCG rate in the ausformed materials was almost independent of loading frequency at a stress intensity factor range of 20 and 30 MPa·m^1/2. Fractographic observations revealed that no intergranular fracture occurred in the ausformed materials, unlike in the non-ausformed ones. These findings suggest that two factors possibly caused the mitigation of FCG rate in hydrogen: (i) modification of the microstructure morphology, i.e., refinement and elongation, and (ii) an increase in the cohesive strength of interfaces under the influence of hydrogen.

对JIS-SCM440型铬钼钢进行了空气和90 MPa氢气条件下的疲劳试验。结果与抗拉强度相近（≈950 MPa和≈1050 MPa）的同一材料的非变形试样进行了比较。与非弯曲材料相比，弯曲材料表现出优异的抗氢诱导疲劳裂纹加速扩展（FCG）的能力，有效地降低了氢环境下循环载荷下的裂纹扩展速率。他们将加速比（即氢气中相对于空气中的相对FCG速率）保持在10到40倍之间，比非变形的对应物低一个数量级。尽管它们的强度水平很高（即抗拉强度大于900 MPa），但在应力强度因子为20和30 MPa·m1/2的范围内，变形材料中的FCG速率几乎与加载频率无关。断口观察表明，与非形变材料不同，形变材料没有发生晶间断裂。这些发现表明，两个因素可能导致氢中FCG速率的减缓：(i)微观形貌的改变，即细化和延伸；（ii）在氢的影响下界面的内聚强度增加。

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引用次数: 0

Effect of ultrasonic peening treatment on the crack initiation behavior of extruded Mg-Gd-Zn-Zr alloys under very high cycle regime 超声波强化处理对超高循环条件下挤压镁-钆-锌-锆合金裂纹萌生行为的影响

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-09 DOI: 10.1016/j.ijfatigue.2025.108812

Min Zhan , Xue Li , Hai Xiong , Xinglin Yang , Yao Chen , Yongjie Liu , Chong Wang , Lang Li , Bing Xue , Yongbo Li , Qingyuan Wang , Chao He

This study examines the impact of ultrasonic peening treatment (UPT) on the very high cycle fatigue resistance of extruded Mg-Gd-Zn-Zr alloy. The findings reveal a significant alteration in crack initiation sites following UPT. The plastic deformation of the surface layer, residual stress, and the vacuum environment induced by the inward movement of the initiation site collectively contribute to an extended fatigue life of the specimen. By establishing a parameter M that elucidates the competitive relationship between subsurface and internal crack initiation, an evaluation model for crack initiation location post-UPT was obtained. Furthermore, by integrating the principle governing the formation of inclined fine granular area (FGA) morphology at the initiation site with the Paris law, a post-failure life analysis model based on the FGA initiation mode was developed.

本文研究了超声强化处理（UPT）对挤压Mg-Gd-Zn-Zr合金超高抗周疲劳性能的影响。研究结果揭示了在UPT后裂纹起裂位置的显著变化。表层的塑性变形、残余应力和由起始点向内移动引起的真空环境共同有助于延长试样的疲劳寿命。通过建立表征地下与内部裂纹起裂竞争关系的参数M，得到了upt后裂纹起裂位置的评价模型。在此基础上，将起裂部位倾斜细颗粒区（FGA）形态形成原理与Paris定律相结合，建立了基于FGA起裂模式的失效后寿命分析模型。

引用次数: 0

Enhancing fatigue performance of laser powder bed fused metals through controlling contour parameters and structures 通过控制激光粉末床熔敷金属的轮廓参数和结构来提高其疲劳性能

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-09 DOI: 10.1016/j.ijfatigue.2025.108811

Hongzhuang Zhang , Changyou Li , Shujie Cao , Ivan Sergeichev , Guian Qian

Side surface quality is a critical concern in the fatigue performance of laser powder bed fused (PBF-LB) components. Increasing contour passes with customized parameters along sample edge can tune side surface/subsurface quality and thereby enhance fatigue resistance. This study critically evaluates the surface and subsurface characteristics resulting from varying contour parameters and their impact on the fatigue performance of PBF-LB 304L steel through multiple detailed characterizations. The fatigue damage mechanisms for varying contour parameters are investigated through fatigue fractography, temperature field analysis, and microstructural evolution. Results indicate that optimal contour parameters differed from infill parameters due to the energy absorption from powder fusion and solidification remelting. The contour defects, including spherical vapor cavities and irregular lack-of-fusion (LoF) defects resulting from inappropriate parameters, significantly degrade fatigue lifetime due to their high-stress concentration factors. Appropriate contour parameters (approximately 300 J/mm³ in energy density) can minimize defect content while simultaneously enhancing microstructural heterogeneity in the contour region. The identified physical mechanisms of defect formation and fatigue damage will assist in designing and optimizing contour process for enhancing fatigue performance.

侧面质量是影响激光粉末床熔合（PBF-LB）部件疲劳性能的关键因素。增加沿样品边缘定制参数的轮廓道次可以调整侧面/次表面质量，从而提高抗疲劳性。本研究通过多种详细表征，批判性地评估了由不同轮廓参数引起的PBF-LB 304L钢的表面和地下特征及其对疲劳性能的影响。通过疲劳断口分析、温度场分析和显微组织演化等研究了不同轮廓参数下的疲劳损伤机理。结果表明，由于粉末熔合和凝固重熔的能量吸收，最佳轮廓参数与填充参数存在差异。轮廓缺陷，包括球形汽腔和不规则的LoF缺陷，由于参数不合适而导致的高应力集中系数，显著降低了疲劳寿命。适当的轮廓参数（能量密度约为300 J/mm3）可以最大限度地减少缺陷含量，同时增强轮廓区域的微结构非均质性。识别缺陷形成和疲劳损伤的物理机制将有助于轮廓工艺的设计和优化，以提高疲劳性能。

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引用次数: 0

Isothermal low-cycle fatigue and fatigue-creep behaviour of boron-added 9% Cr martensitic stainless steel at 600°C 加硼9% Cr马氏体不锈钢在600℃下的等温低周疲劳和疲劳蠕变行为

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-06 DOI: 10.1016/j.ijfatigue.2024.108800

Michal Bartošák , Vladimír Mára , Eliška Galčíková , Michal Slaný , Miroslav Španiel , Ladislav Poczklán , Ivo Šulák

In this article, strain-controlled Low-Cycle Fatigue (LCF) and fatigue-creep tests were conducted on COST FB2, a boron-added 9% Cr martensitic stainless steel, at 600°C. LCF tests were performed with a mechanical strain rate of

1 \times 1 0^{- 3}

/s, while the fatigue-creep tests involved either tensile or compressive strain dwells lasting 600 s. Both the LCF and fatigue-creep tests revealed cyclic softening behaviour, with the magnitude of relaxed stress decreasing with cycles in the fatigue-creep tests. This softening was associated with the coarsening of the laths and subgrains and a reduction in dislocation density, both of which were more pronounced for LCF loading at higher strain amplitudes and during fatigue-creep loading. Investigations into the damage mechanisms identified environmentally assisted transgranular cracking as the predominant failure mode, with the severity of oxidation-induced cracking increasing with higher applied strain amplitudes or during fatigue-creep loading with compressive dwell, while cracking was suppressed during tests with tensile strain dwell. Finally, a damage model combining the strain-life approach with a time-dependent damage term was proposed to effectively predict the reduction in lifetime during fatigue-creep tests compared to continuous LCF cycling.

本文对COST FB2（添加硼的9% Cr马氏体不锈钢）在600℃下进行了应变控制低周疲劳（LCF）和疲劳蠕变试验。LCF试验以机械应变速率1×10−3/s进行，而疲劳蠕变试验涉及拉伸或压缩应变停留时间为600 s。LCF和疲劳蠕变试验均显示出循环软化行为，疲劳蠕变试验中随循环次数的增加，松弛应力的大小减小。这种软化与板条和亚晶的粗化以及位错密度的降低有关，这两种情况在高应变幅和疲劳蠕变加载下的LCF加载中更为明显。对损伤机制的研究发现，环境辅助的穿晶裂纹是主要的破坏模式，氧化诱发裂纹的严重程度随着施加应变幅值的增加或在疲劳蠕变加载下的压缩停留而增加，而在拉伸应变停留试验中裂纹被抑制。最后，提出了一种结合应变-寿命方法和时间相关损伤项的损伤模型，与连续LCF循环相比，可以有效地预测疲劳-蠕变试验中寿命的减少。

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引用次数: 0

High cycle fatigue performance and corresponding fracture behaviors of GH4169 studs formed by thread warm rolling process 螺纹温轧GH4169螺柱高周疲劳性能及断裂行为

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-04 DOI: 10.1016/j.ijfatigue.2025.108808

Yanli Lu, Liyuan Hu, Ting Li, Gang Ran, Xiaowei Yi, Yukun Sun, Zhenyang Kong, Kuangshi Yan, Rui Hu, Hong Wang

Threaded components like bolts and studs, are prone to fatigue failures due to high stress concentration. GH4169 superalloy widely used in the aerospace field has excellent mechanical properties in high temperature environment and is ideal for high strength thread fasteners. In this study, the thread warm rolling process is developed to prepare GH4169 studs samples with enhanced fatigue performance. Firstly, the configuration of the rolling apparatus is introduced and described. Then, thread forming experiments are conducted on GH4169 matrix by use of the thread warm rolling process and traditional thread turning process respectively. The fatigue performance and mechanical properties of these formed studs are evaluated. Compared to the turning process, surface finish of thread root is further improved from R_a 0.26 to R_a 0.13, and increased microhardness distributed in the severe plastic deformation (SPD) layer are achieved for thread warm rolling process. The warm rolling process induces the SPD layer depth of approximately 80–100 μm at the thread root, significantly enhancing mechanical properties here and improving fatigue performance of overall parts. High cycle fatigue tests demonstrate that GH4169 studs formed by warm rolling process exhibit a fatigue life about 25 times greater than those formed by turning process.

像螺栓和螺柱这样的螺纹部件，由于应力高度集中，容易疲劳失效。GH4169高温合金广泛应用于航空航天领域，在高温环境下具有优异的机械性能，是高强度螺纹紧固件的理想材料。在本研究中，开发了螺纹温轧工艺，以制备具有增强疲劳性能的GH4169螺柱样品。首先对轧制装置的结构进行了介绍和描述。然后，分别采用螺纹温轧工艺和传统螺纹车削工艺在GH4169基体上进行了螺纹成形实验。对这些成形螺柱的疲劳性能和力学性能进行了评价。与车削工艺相比，螺纹根部表面光洁度由Ra 0.26进一步提高到Ra 0.13，螺纹热轧工艺提高了分布在SPD层的显微硬度。热轧工艺在螺纹根部形成了约80 ~ 100 μm的SPD层，显著提高了螺纹根部的力学性能，并改善了整体的疲劳性能。高周疲劳试验表明，热轧成形GH4169螺栓的疲劳寿命是车削成形GH4169螺栓的25倍左右。

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引用次数: 0

Effect of undercooled austenite cooling rate on the low cycle fatigue properties of an austempering bainitic steel 过冷奥氏体冷却速率对奥氏体贝氏体钢低循环疲劳性能的影响

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-04 DOI: 10.1016/j.ijfatigue.2025.108809

Yingnan Li , Yu Zhang , Xiaoyan Long , Ranran Zhu , Wanshuai Wang , Yanguo Li , Zeliang Liu

Carbide-free bainitic microstructures with different morphologies were obtained by designing different cooling rates in medium-carbon bainitic steel, and the effect of undercooled austenite cooling rate on the low cycle fatigue (LCF) properties of austempering bainitic steels was systematically investigated. The results show that with the reduction of the cooling rate, the bainitic ferrite laths are coarsened, the content of retained austenite is reduced, and the proportion of filmy retained austenite is increased. The samples with a cooling rate of 30 °C/s at low strain amplitude possessed higher fatigue life, while the samples with a cooling rate of 0.3 °C/s at high strain amplitude exhibited higher fatigue life. This is because the phase transformation induced plasticity (TRIP) effect at low strain amplitude improves the samples’ plastic deformation resistance. In contrast, the brittle martensite produced by the TRIP effect at high strain amplitude is more likely to provide a crack propagation path.

通过设计不同的冷却速率，在中碳贝氏体钢中获得了不同形貌的无碳化物贝氏体组织，并系统研究了过冷奥氏体冷却速率对等温贝氏体钢低周疲劳性能的影响。结果表明：随着冷却速率的降低，贝氏体铁素体板条粗化，残余奥氏体含量降低，膜状残余奥氏体比例增加；在低应变幅下，冷却速度为30℃/s的试样具有较高的疲劳寿命，而在高应变幅下，冷却速度为0.3℃/s的试样具有较高的疲劳寿命。这是因为低应变幅值下的相变诱导塑性（TRIP）效应提高了试样的塑性变形抗力。相反，高应变幅下TRIP效应产生的脆性马氏体更有可能提供裂纹扩展路径。

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引用次数: 0

Crack growth in laser powder bed fusion fabricated alloy 718 at 650 °C under static and cyclic loading

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-04 DOI: 10.1016/j.ijfatigue.2025.108810

Halsey E. Ostergaard , Joshua D. Pribe , M. Tarik Hasib , Thomas Siegmund , Jamie J. Kruzic

The role of microstructure in influencing 650 °C crack growth behavior for laser powder bed fusion (LPBF) fabricated nickel alloy 718 was examined by applying two post-build heat treatments and comparing to wrought material. The first heat treatment (solution and ageing) retained the elongated grain structure along the build direction. The second used hot isostatic pressing (HIP) prior to the solution and aging treatment to mostly recrystallize the microstructure. At high cyclic frequency (30 Hz), crack growth was mixed transgranular and intergranualr and differences in the crack growth rates among samples were primary caused by grain size differences and corresponding transgranular crack path roughness. Under static loading or low frequency (0.1 Hz) cyclic loading, intergranular crack growth dominated. Without HIP, the LPBF material had highly anisotropic behavior with a high threshold for crack extension when the crack plane tried to cut across the elongated grain structure. After HIP, the LPBF fabricated material displayed excellent resistance to intergranular crack extension at both 0.1 Hz and constant applied load due to a large fraction of Σ3 special boundaries which are highly resistant to intergranular oxidation. The results suggest LPBF with HIP treatment can give a grain boundary engineered 718 microstructure for elevated temperature applications.

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引用次数: 0

Investigation of fatigue behavior in prestressed CFRP reinforced RC beams exposed to natural subtropical environment 暴露于亚热带自然环境中的预应力 CFRP 加固 RC 梁的疲劳行为研究

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-01-03 DOI: 10.1016/j.ijfatigue.2024.108802

Yilin Wang , Ruonan Zhang , Wen Li , Peiyan Huang , Hangyue Cui , Pengyu Wei , Roman Wan-Wendner , Xinyan Guo

This study explores the fatigue behavior of prestressed CFRP-reinforced concrete (RC) beams in subtropical environments, addressing the gap in understanding their long-term performance under natural exposure. Five specimens were subjected to one year of natural exposure under sustained load conditions before fatigue testing. During the exposure period, the strain on the CFRP laminate was monitored, and a decrease of 5.37% in prestress loss after exposing 300 days was observed. The digital image correlation (DIC) method was employed to capture the crack initiation and growth during the fatigue tests, with detailed analyses of crack growth rates, deflection evolution, and failure modes. Experimental results indicated that natural exposure accelerates fatigue crack growth compared to the results of the unexposed RC beams tested by this group. Moreover, the finite element model (FEM) was developed to account for CFRP-concrete interface degradation due to natural exposure and material nonlinearities, allowing for the determination of the J-integral of the main crack. Fatigue life prediction models, based on experimentally obtained crack growth rates and stress intensity factors (SIF) calculated using the J-integral, were derived. The predicted fatigue lives were within a 20% error margin of the experimental results, demonstrating the reliability of the proposed models.

本研究探讨了亚热带环境下预应力cfrp -钢筋混凝土（RC）梁的疲劳行为，解决了在自然暴露下了解其长期性能的空白。在进行疲劳试验之前，五个试件在持续载荷条件下自然暴露一年。暴露期间，对CFRP复合材料进行应变监测，暴露300 d后预应力损失减小5.37%。采用数字图像相关（DIC）方法捕捉疲劳试验过程中裂纹的萌生和扩展过程，并对裂纹扩展速率、挠度演化和破坏模式进行了详细分析。实验结果表明，与未暴露的RC梁相比，自然暴露加速了疲劳裂纹的扩展。此外，开发了有限元模型（FEM）来考虑由于自然暴露和材料非线性导致的cfrp -混凝土界面退化，从而可以确定主裂缝的j积分。基于实验得到的裂纹扩展速率和用j积分计算的应力强度因子（SIF），推导了疲劳寿命预测模型。预测疲劳寿命与试验结果误差在20%以内，证明了所提模型的可靠性。

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引用次数: 0