International Journal of Fatigue最新文献

Modeling of statistical and spectral properties of non-Gaussian random vibration fatigue loads using Higher Order Spectra

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-25 DOI: 10.1016/j.ijfatigue.2025.109004

Peter Wolfsteiner, Arvid Trapp

A theoretical analysis of random vibration fatigue is possible in time- or frequency-domain. In time-domain, sampled signal realizations are used, whereas the power spectral density (PSD) method is based on second-order statistics in frequency-domain. PSDs have important advantages over the sampled time-domain signals: (i) PSDs use a statistical model, enabling sound modeling of extreme value statistics, (ii) PSDs come along with a beneficial data reduction in computational analysis. However, PSD models rely on the hypothesis of Gaussianity. Practical applications often deviate from this assumption causing significantly false fatigue load estimations. Various improvements were proposed in the past, based on simplifying assumptions or with limited validity, not yet providing a theoretically sound solution for general non-Gaussian random fatigue loads. This paper follows the hypothesis that higher-order spectra (HOS) can model general non-Gaussian random fatigue loads. HOS extend the second-order PSD model in spectral domain. Using typical, different non-Gaussian signal types, the paper demonstrates significant improvements based on the trispectrum (4th-order HOS). To achieve this goal, a novel method for the synthetic generation of non-Gaussian time realizations from a HOS description is presented. The results lay the foundation for further work, such as the development of estimation methods for load-spectra from HOS.

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引用次数: 0

Machine learning insight into the mean stress impact on fatigue life of additively manufactured 18Ni300 maraging steel under various multiaxial stress paths

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-23 DOI: 10.1016/j.ijfatigue.2025.109023

Aleksander Karolczuk, Andrzej Kurek

This study investigates the effects of mean axial and mean shear stresses on the fatigue life of Laser Powder Bed Fusion (LPBF) 18Ni300 maraging steel under uniaxial, torsional, in-phase, and out-of-phase axial–torsional loading conditions. A Gaussian Process (GP) model is employed to analyze fatigue life data, enabling (i) the estimation of the impact of specific mean stress components and (ii) the identification of dominant damage mechanisms through the selection of key stress-related predictors. Results reveal that static and alternating axial stresses similarly influence fatigue life, an effect captured by the maximum axial stress. This is attributed to the stress-raising geometry of surface pits, which limits axial ratcheting and reinforces the dominant role of maximum axial stress. In contrast, mean shear stress induces angular displacement ratcheting, leading to additional fatigue damage that maximum stress alone cannot account for. Under out-of-phase loading, this angular ratcheting is suppressed, significantly reducing the influence of mean shear stress on fatigue life. The GP model effectively captures the non-linear relationships between stress components and fatigue life. These results emphasize the critical role of mean stress effects and surface features in designing and evaluating AM components, enhancing the understanding of fatigue damage mechanisms in AM steels and aiding the development of predictive life models for complex loading conditions.

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引用次数: 0

Effect of bolt preload uncertainty on fatigue reliability of single-lap, countersunk composite bolted joints considering forced assembly interaction

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-22 DOI: 10.1016/j.ijfatigue.2025.109017

Yunong Zhai , Hao Qu , Dongsheng Li , Ende Ge , Ruiheng Xiao , Jian Yang

Bolt preload plays a crucial part in ensuring the security of composite bolted joints. The actual bolt preload level displays noticeable fluctuation during aircraft assembly, impacting the fatigue reliability of joints. Assembly gaps commonly arise at the mating surface of composite airframes, and forced assembly is a prevalent method for closing the gaps before applying bolt preload, which leads to the bolt head fatigue cracking, weakening the fatigue performance of joints. In this study, the effect of bolt preload uncertainty on fatigue reliability of single-lap, countersunk composite bolted joints considering forced assembly interaction was systematically evaluated. The combination of progressive fatigue damage model (PFDE) and extended finite element method (XFEM) was developed to characterize the hole bearing damage and the bolt head fatigue cracking respectively. The findings show that the joints with forced assembly present a shorter fatigue life with increasing bolt preload under the fatigue load level of 70%

F_{x}^{bro} (2 %)

due to bolt head fatigue cracking. Higher bolt preload makes the bolt head fatigue cracking occur earlier, thus stiffness degrades and fatigue failure more rapidly. The bolt head crack size shows a growing trend with increased bolt preload, leading to a lower residual strength of joints. With a Gaussian distribution of actual bolt preload, the composite bolted joints after forced assembly presents a right-skewed distribution fatigue life under the fatigue load level of 70%

F_{x}^{bro} (2 %)

, since the bolt head fatigue cracking would be triggered at a bolt preload lower than the mean value.

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引用次数: 0

Enhanced high-cycle fatigue behavior of electrodeposited nickel plates with optimized grain-size gradient structures

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-22 DOI: 10.1016/j.ijfatigue.2025.109018

R.Q. Cao , Y.L. Lu , F.X. Meng , J. Pan , Q. Yu , Y. Li

Gradient structures fabricated using plastic deformation methods have been demonstrated to exhibit excellent fatigue performances. However, achieving an optimal gradient structure remains challenging because of methodological limitations. In this study, nickel plates with varying grain-size gradient structures (GSs) were synthesized in a controllable manner via direct-current electrodeposition. Fatigue tests revealed that the GS samples, ranging from coarse grains (CGs, 4 μm) to nano-grains (NGs, 40 nm), exhibited higher fatigue strengths compared to the homogeneous CG sample. Detailed observations showed that cracks were initiated in the surface layers of the GS samples, while severe plastic deformation was mitigated, demonstrating a superior co-deformation capability. An optimized structure with a linear hardness gradient ranging from 2.3 to 3.4 GPa and grain sizes ranging from CGs to ultrafine grains (UFGs, 170 nm) led to a further enhanced fatigue performance, achieving a fatigue limit of 325 MPa and a fatigue ratio of 0.38. This improved performance was attributed to the ability of the structure to disperse cyclic deformation and suppress stress concentration. These findings highlight the potential of controllably synthesized grain-size gradient structures to enhance the high-cycle fatigue properties of nickel plates.

{"title":"Enhanced high-cycle fatigue behavior of electrodeposited nickel plates with optimized grain-size gradient structures","authors":"R.Q. Cao , Y.L. Lu , F.X. Meng , J. Pan , Q. Yu , Y. Li","doi":"10.1016/j.ijfatigue.2025.109018","DOIUrl":"10.1016/j.ijfatigue.2025.109018","url":null,"abstract":"<div><div>Gradient structures fabricated using plastic deformation methods have been demonstrated to exhibit excellent fatigue performances. However, achieving an optimal gradient structure remains challenging because of methodological limitations. In this study, nickel plates with varying grain-size gradient structures (GSs) were synthesized in a controllable manner via direct-current electrodeposition. Fatigue tests revealed that the GS samples, ranging from coarse grains (CGs, 4 μm) to nano-grains (NGs, 40 nm), exhibited higher fatigue strengths compared to the homogeneous CG sample. Detailed observations showed that cracks were initiated in the surface layers of the GS samples, while severe plastic deformation was mitigated, demonstrating a superior co-deformation capability. An optimized structure with a linear hardness gradient ranging from 2.3 to 3.4 GPa and grain sizes ranging from CGs to ultrafine grains (UFGs, 170 nm) led to a further enhanced fatigue performance, achieving a fatigue limit of 325 MPa and a fatigue ratio of 0.38. This improved performance was attributed to the ability of the structure to disperse cyclic deformation and suppress stress concentration. These findings highlight the potential of controllably synthesized grain-size gradient structures to enhance the high-cycle fatigue properties of nickel plates.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"198 ","pages":"Article 109018"},"PeriodicalIF":5.7,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877465","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

Microstructural insights into effects of pressurized water reactor environment and cyclic loading parameters on the low cycle fatigue behavior of 316L stainless steel

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-21 DOI: 10.1016/j.ijfatigue.2025.109016

Aleks Vainionpää, Pedro A. Ferreirós, Tommi Seppänen, Zaiqing Que

Austenitic stainless steels, commonly used in light water reactor coolant environments, can be susceptible to environmentally assisted fatigue due to non-monotonic loading conditions, primarily associated with load-follow operations, thermal transients, or intermittent plant shutdowns and start-ups. The effects of a pressurized water reactor (PWR) environment containing hydrogen and cyclic loading parameters on the low cycle fatigue (LCF) behavior of 316L stainless steel were investigated by comprehensive striation spacing evaluation and advanced microscopic characterizations. The exposure to a PWR environment results in a decreased LCF lifetime, an enhanced fatigue crack initiation and an accelerated fatigue crack growth rate of 316L austenitic stainless steel. The interaction between hydrogen and localized deformation contributes to the observed acceleration of fatigue crack growth rate in a PWR environment. The evaluation of the effect of waveform (periodic underload PUL, periodic overload POL and constant amplitude sawtooth CA) shows that both PUL and POL reduce the low cycle fatigue lifetime, accelerate the fatigue crack growth rate and advance the cycle where fatigue crack initiation occurs compared to CA loading. LCF waveform strongly influences the shear band formation, localization of plastic deformation and stress state.

{"title":"Microstructural insights into effects of pressurized water reactor environment and cyclic loading parameters on the low cycle fatigue behavior of 316L stainless steel","authors":"Aleks Vainionpää, Pedro A. Ferreirós, Tommi Seppänen, Zaiqing Que","doi":"10.1016/j.ijfatigue.2025.109016","DOIUrl":"10.1016/j.ijfatigue.2025.109016","url":null,"abstract":"<div><div>Austenitic stainless steels, commonly used in light water reactor coolant environments, can be susceptible to environmentally assisted fatigue due to non-monotonic loading conditions, primarily associated with load-follow operations, thermal transients, or intermittent plant shutdowns and start-ups. The effects of a pressurized water reactor (PWR) environment containing hydrogen and cyclic loading parameters on the low cycle fatigue (LCF) behavior of 316L stainless steel were investigated by comprehensive striation spacing evaluation and advanced microscopic characterizations. The exposure to a PWR environment results in a decreased LCF lifetime, an enhanced fatigue crack initiation and an accelerated fatigue crack growth rate of 316L austenitic stainless steel. The interaction between hydrogen and localized deformation contributes to the observed acceleration of fatigue crack growth rate in a PWR environment. The evaluation of the effect of waveform (periodic underload PUL, periodic overload POL and constant amplitude sawtooth CA) shows that both PUL and POL reduce the low cycle fatigue lifetime, accelerate the fatigue crack growth rate and advance the cycle where fatigue crack initiation occurs compared to CA loading. LCF waveform strongly influences the shear band formation, localization of plastic deformation and stress state.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"198 ","pages":"Article 109016"},"PeriodicalIF":5.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874684","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

Time-dependent fatigue reliability analysis of heavy-haul railway steel bridges based on coupled train-track-bridge dynamic analysis

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-20 DOI: 10.1016/j.ijfatigue.2025.109011

Sheng-Wang Zhang , Hao-Peng Qiao , Xue-Yan Song , Zhao-Hui Lu , Chun-Qing Li

Due to the severity and sudden onset of damage, fatigue failure in heavy-haul railway bridges has become a critical concern for all stakeholders. This study develops a comprehensive time-dependent fatigue reliability framework based on stress range analysis, where stress ranges, regarded as the primary drivers of fatigue damage, are systematically characterized for their stochastic and dynamic nature. The developed framework integrates three key innovations: (1) implementation of a coupled train-track-bridge system-based stochastic dynamic analysis, enhancing conventional static methods to more accurately characterize the dynamical development of the stress range; (2) development of a continuous nonstationary stochastic process model for the stress range that surpasses traditional stationary assumptions in realism; and (3) application of a fourth-moment transformation method for time-dependent reliability analysis involving nonstationary stochastic processes. The proposed framework is validated through application to an actual heavy-haul railway steel bridge, revealing that both the stress range and the fatigue limit state function exhibit time-dependent, nonstationary, and non-Gaussian characteristics. Notably, incorporating dynamic analysis under a nonstationary assumption proves to be critical, as conventional methods tend to overestimate fatigue reliability. This study provides valuable insights for engineers in the design, assessment, and management of railway bridges under stochastic fatigue loads.

{"title":"Time-dependent fatigue reliability analysis of heavy-haul railway steel bridges based on coupled train-track-bridge dynamic analysis","authors":"Sheng-Wang Zhang , Hao-Peng Qiao , Xue-Yan Song , Zhao-Hui Lu , Chun-Qing Li","doi":"10.1016/j.ijfatigue.2025.109011","DOIUrl":"10.1016/j.ijfatigue.2025.109011","url":null,"abstract":"<div><div>Due to the severity and sudden onset of damage, fatigue failure in heavy-haul railway bridges has become a critical concern for all stakeholders. This study develops a comprehensive time-dependent fatigue reliability framework based on stress range analysis, where stress ranges, regarded as the primary drivers of fatigue damage, are systematically characterized for their stochastic and dynamic nature. The developed framework integrates three key innovations: (1) implementation of a coupled train-track-bridge system-based stochastic dynamic analysis, enhancing conventional static methods to more accurately characterize the dynamical development of the stress range; (2) development of a continuous nonstationary stochastic process model for the stress range that surpasses traditional stationary assumptions in realism; and (3) application of a fourth-moment transformation method for time-dependent reliability analysis involving nonstationary stochastic processes. The proposed framework is validated through application to an actual heavy-haul railway steel bridge, revealing that both the stress range and the fatigue limit state function exhibit time-dependent, nonstationary, and non-Gaussian characteristics. Notably, incorporating dynamic analysis under a nonstationary assumption proves to be critical, as conventional methods tend to overestimate fatigue reliability. This study provides valuable insights for engineers in the design, assessment, and management of railway bridges under stochastic fatigue loads.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"198 ","pages":"Article 109011"},"PeriodicalIF":5.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869041","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

Acoustic emission-driven fatigue damage evolution equation and life prediction of composite laminates

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-20 DOI: 10.1016/j.ijfatigue.2025.109012

Fan Dong , Yazhi Li , Biao Li

Conventional acoustic emission (AE) establishes correlations between signals and damage, often relying on machine learning or threshold-based approaches. These methods either lack quantitative rigor or depend on black-box models with limited interpretability. To address these limitations, this study leverages AE signals to develop a physics-informed damage evolution equation, capturing the underlying physical mechanisms governing fatigue damage in composite laminates. By integrating AE signal analysis with a phenomenological framework, the proposed model extracts damage state from AE data and incorporates material-specific physical parameters to accurately describe damage progression and predict fatigue life. This approach characterizes the fatigue damage evolution using AE cumulative energy, effectively reconstructing the three critical stages of fatigue: primary damage, steady-state damage, and accelerated damage. AE data from plain-woven glass fiber/cyanate composite laminate (GFRP) and multidirectional symmetric carbon fiber CCF800H/AC531 laminates (CFRP) with open-hole subjected to tension–tension loading were utilized for validation. The results showed that the predicted fatigue life for GFRP and CFRP falls within 2 and 2.5 times their respective error bands. These findings underscore the potential of this physics-guided AE-based methodology for applications in structural health monitoring and fatigue life prediction of composite materials.

{"title":"Acoustic emission-driven fatigue damage evolution equation and life prediction of composite laminates","authors":"Fan Dong , Yazhi Li , Biao Li","doi":"10.1016/j.ijfatigue.2025.109012","DOIUrl":"10.1016/j.ijfatigue.2025.109012","url":null,"abstract":"<div><div>Conventional acoustic emission (AE) establishes correlations between signals and damage, often relying on machine learning or threshold-based approaches. These methods either lack quantitative rigor or depend on black-box models with limited interpretability. To address these limitations, this study leverages AE signals to develop a physics-informed damage evolution equation, capturing the underlying physical mechanisms governing fatigue damage in composite laminates. By integrating AE signal analysis with a phenomenological framework, the proposed model extracts damage state from AE data and incorporates material-specific physical parameters to accurately describe damage progression and predict fatigue life. This approach characterizes the fatigue damage evolution using AE cumulative energy, effectively reconstructing the three critical stages of fatigue: primary damage, steady-state damage, and accelerated damage. AE data from plain-woven glass fiber/cyanate composite laminate (GFRP) and multidirectional symmetric carbon fiber CCF800H/AC531 laminates (CFRP) with open-hole subjected to tension–tension loading were utilized for validation. The results showed that the predicted fatigue life for GFRP and CFRP falls within 2 and 2.5 times their respective error bands. These findings underscore the potential of this physics-guided AE-based methodology for applications in structural health monitoring and fatigue life prediction of composite materials.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"198 ","pages":"Article 109012"},"PeriodicalIF":5.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874683","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

Comparison of tensile and LCF behaviour of heat-treated Inconel 718 printed by LPBF and LW-DED at different temperatures

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-20 DOI: 10.1016/j.ijfatigue.2025.109010

Vivek Kumar Singh , Debaraj Sahoo , Anish Ranjan , Murugaiyan Amirthalingam , Shyamprasad Karagadde , Sushil K. Mishra

This study investigates the effect of processing routes on the tensile and low-cycle fatigue (LCF) performance of Inconel 718 at room temperature (RT) and elevated temperatures fabricated via Laser Powder Bed Fusion (LPBF) and Laser Wire Direct Energy Deposition (LW-DED) under identical heat treatment conditions. Despite the contrasting differences in the solidification microstructures, including dendritic arm spacing, grain size, and the size of secondary phases, the as-printed tensile and LCF behavior of both routes remained comparable. On the contrary, heat-treated LPBF samples exhibited significantly better mechanical properties than LW-DED conditions due to the influence of printing signatures. Among all conditions, LPBF-STA demonstrated the highest tensile strength and LCF performance, surpassing wrought Inconel 718. In contrast, while the LW-DED-STA exhibited good tensile strength and ductility, it demonstrated a significantly poor LCF performance, especially at 650°C. The cyclic softening in the STA samples was due to a combined variation in both back stress and friction stress, attributed to the reduction in the size of γ’’-precipitates. The work reveals the similarity and contrast in the mechanical properties of two processing routes in the as-printed and heat-treated conditions, respectively, and provides insights that are helpful to design Inconel 718 components.

本研究探讨了在相同的热处理条件下，通过激光粉末床熔融（LPBF）和激光线直接能量沉积（LW-DED）制造的Inconel 718在室温（RT）和高温（LCF）条件下的拉伸和低循环疲劳（LCF）性能的加工路线影响。尽管凝固微观结构（包括树枝状臂间距、晶粒大小和次生相的大小）存在差异，但这两种方法的印刷拉伸和低熔点性能仍然相当。相反，由于印刷特征的影响，热处理 LPBF 样品的机械性能明显优于 LW-DED 条件。在所有条件中，LPBF-STA 的拉伸强度和低熔点性能最高，超过了锻造的 Inconel 718。相比之下，虽然 LW-DED-STA 表现出良好的抗拉强度和延展性，但其 LCF 性能明显较差，尤其是在 650°C 时。STA 样品的循环软化是由于背应力和摩擦应力的综合变化造成的，这归因于 γ''-沉淀物尺寸的减小。这项研究揭示了两种加工工艺分别在压印和热处理条件下的机械性能的相似性和对比性，并提供了有助于设计铬镍铁合金 718 部件的见解。

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引用次数: 0

Experimental study on Fe-SMA strengthening technique for cope hole fatigue cracks in orthotropic steel bridge decks

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-19 DOI: 10.1016/j.ijfatigue.2025.109003

Zhilin Lyu , Xu Jiang , Xuhong Qiang

Iron-based shape memory alloys (Fe-SMAs) have emerged as innovative smart materials for structural rehabilitation. However, their application on fatigue repairing in steel bridges remains limited. This study aims to examine the effectiveness of Fe-SMA strengthening for repairing fatigue-cracked cope holes in orthotropic steel bridge deck (OSD). Experimental investigations were conducted on three full-scale specimens: one reference and two strengthened with unilateral and bilateral Fe-SMA configurations, respectively. Then a comprehensive fatigue testing was performed to evaluate failure mechanisms and fatigue performance improvement of diaphragm cope hole cracks. Finally, the feasibility of Fe-SMA strengthening for such cracks was verified through stress monitoring on an in-service steel bridge. Results demonstrate that Fe-SMA strengthening achieves a synergistic effect of prestressing introduction and local rigidity enhancement at the damaged cope holes, substantially improving fatigue performance. The equivalent fatigue lives of repaired cope hole increased by factors of 10.9 to 62. Bilateral reinforcement exhibited superior fatigue improvement compared to unilateral reinforcement, achieving complete suppression of crack propagation. Field monitoring revealed that under random traffic loading, all stress amplitudes at the cracked cope hole details after combined Fe-SMA bonding and stop-hole method were below the constant amplitude fatigue limit (CAFL), satisfying infinite-life design criteria.

铁基形状记忆合金（Fe-SMA）已成为用于结构修复的创新型智能材料。然而，它们在钢桥疲劳修复方面的应用仍然有限。本研究旨在考察 Fe-SMA 强化材料在修复正交异性钢桥面（OSD）疲劳开裂塞孔中的有效性。本研究对三个全尺寸试样进行了实验研究：一个参考试样和两个分别采用单侧和双侧 Fe-SMA 配置进行加固的试样。然后进行了全面的疲劳测试，以评估横隔梁斜孔裂缝的失效机理和疲劳性能改善情况。最后，通过对在役钢桥进行应力监测，验证了对此类裂缝进行 Fe-SMA 加固的可行性。结果表明，Fe-SMA 加固在受损的斜孔处实现了预应力引入和局部刚度增强的协同效应，大大改善了疲劳性能。修复后的斜孔等效疲劳寿命提高了 10.9 至 62 倍。与单侧加固相比，双侧加固的疲劳改善效果更好，能完全抑制裂纹扩展。现场监测结果表明，在随机交通荷载条件下，Fe-SMA 粘接和止动孔组合方法修复后的开裂坡口细节处的所有应力幅值均低于恒幅疲劳极限 (CAFL)，满足无限寿命设计标准。

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引用次数: 0

A novel surface strengthening technique for enhancing fatigue properties of 6061 Al alloy

IF 5.7 2区材料科学 Q1 ENGINEERING, MECHANICAL

International Journal of Fatigue

Pub Date : 2025-04-19 DOI: 10.1016/j.ijfatigue.2025.109000

B.S. Gong , Z.J. Zhang , H.W. Wang , R. Liu , H.Z. Liu , H. Wang , G. Purcek , M. Demirtas , H. Yanar , Z.F. Zhang

A new surface spinning rolling (SR) strengthening technique was developed to enhance the fatigue properties of 6061 Al alloy. The traditional shot peening (SP) process can strengthen the sample’s surface, but it increases surface damage, which seriously hinders the improvement of fatigue performance. However, the SR process not only introduces a high residual compressive stress and a hardened layer on the sample surface but also remarkably lowers the surface roughness. Moreover, the SR treatment formed a gradient microstructure on the surface layer of 6061 Al alloy, effectively postponing the initiation and propagation of fatigue cracks. Fatigue experiments demonstrate that after SR treatment, the fatigue strength of 6061 Al alloy increases by 17.9 %, from 223 MPa to 263 MPa. This study demonstrates the significant advantages by the SR process in producing high fatigue-resistant Al alloy components.

引用次数: 0