Fatigue & Fracture of Engineering Materials & Structures最新文献

{"title":"Effect of Build Orientation on Uniaxial Time-Dependent Ratcheting of Polyamide 12 Fabricated by Selective Laser Sintering","authors":"Minjun Zhao,&nbsp;Kaijuan Chen,&nbsp;Qianhua Kan,&nbsp;Guozheng Kang","doi":"10.1111/ffe.14700","DOIUrl":"https://doi.org/10.1111/ffe.14700","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> ABSTRACT</h3>\u0000 \u0000 <p>This study examined the impact of build orientation on the time-dependent ratcheting of polyamide 12 fabricated by selective laser sintering, focusing on the effects of voids and sintering interfaces. Results demonstrate that the ratcheting of the materials is notably time-dependent, with ratcheting strain increasing by 107% when the peak stress duration is extended from 0 to 10 s and by 95% when the loading rate is reduced from 15 to 1 MPa·s⁻¹; additionally, an interaction between creep and ratcheting is identified, suggesting that the loading history also influences the ratcheting of the materials; at high-stress levels (16 ± 22 MPa), the ratcheting of the materials shows a strong dependence on the build orientation, with the ratcheting strain increasing in the order of <i>X</i>0, <i>X</i>90, and <i>X</i>45 orientations (i.e., an increase of approximately 30% from the <i>X</i>0 to <i>X</i>45 orientation), which is attributed to the higher porosity of the materials with the <i>X</i>45 orientation and the larger projection area of voids perpendicular to the loading direction; in contrast, at low-stress levels (12 ± 18 MPa), the ratcheting strains of the materials built in the different orientations are almost the same. These findings provide experimental data support for the structural design of selective laser sintering polyamide 12 and highlight the significant impact of voids and sintering interfaces on the ratcheting of printed parts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Highlights</h3>\u0000 \u0000 <div>\u0000 \u0000 <ul>\u0000 \u0000 <li>The effect of build orientation on uniaxial time-dependent ratcheting was investigated.</li>\u0000 \u0000 <li>The significant impact of voids and sintering interfaces on ratcheting was revealed.</li>\u0000 \u0000 <li>At high-stress levels, the <i>X</i>0 build orientation shows the smallest ratcheting strain.</li>\u0000 \u0000 <li>As void defects preferentially orient in the <i>X</i>45 build orientation, the ratcheting is more pronounced.</li>\u0000 </ul>\u0000 </div>\u0000 </section>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3760-3774"},"PeriodicalIF":3.2,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue Criticality Assessment of Volumetric Defects in Notched Specimens: A Non-Destructive Approach","authors":"Arun Poudel,&nbsp;Jonathan Pegues,&nbsp;Matthew Kelly,&nbsp;Shuai Shao,&nbsp;Nima Shamsaei","doi":"10.1111/ffe.14698","DOIUrl":"https://doi.org/10.1111/ffe.14698","url":null,"abstract":"<div>\u0000 \u0000 <p>This study utilizes linear elastic fracture mechanics to assess the fatigue criticality of volumetric defects in notched specimens with varying geometries. Contrasting to the existing literature, this study assesses the fatigue criticality of defects, prior to fracture, via a non-destructive inspection technique, that is, X-ray computed tomography (XCT). Treating volumetric defects as cracks, based on Murakami's definition, the approach calculates their Mode-I stress intensity factor (SIF) with their local stresses obtained via linear elastic finite element analysis and utilizes the SIF to represent their criticality. For validation, cylindrical and flat specimens with notch root radii of 5 and 50 mm of AlSi10Mg and 17-4 precipitation hardened stainless steel were fabricated, XCT scanned, and tested under fatigue loading. All crack initiating defects, observed from fractography, fell within the 99.3 percentile of the defects with the highest stress intensity factor in the respective specimens.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3746-3759"},"PeriodicalIF":3.2,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Theoretical Fracture Analysis of Anisotropic Elastomers via Direct Ink Writing","authors":"Mirmilad Mirsayar,&nbsp;Mostafa Ghorbani,&nbsp;Ratneshwar Jha","doi":"10.1111/ffe.14695","DOIUrl":"https://doi.org/10.1111/ffe.14695","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents an investigation into the fracture mechanics of additively manufactured elastomers through an integrated theoretical and experimental approach. Elastomeric specimens with varying print orientations are fabricated using direct ink writing (DIW). Tensile tests on both uncracked and pre-cracked specimens are conducted to characterize the mechanical and fracture behavior of the printed elastomers, revealing significant anisotropy resulting from the layer-by-layer nature of DIW. To address this anisotropy, data from tensile experiments on uncracked specimens are used to calibrate an anisotropic constitutive model, which is implemented in finite element simulations to analyze the mixed-mode fracture behavior of pre-cracked specimens. The results indicate that while the critical J-integral varies with print orientation, its ratio to the effective critical distance remains constant, introducing a novel critical parameter for fracture analysis of anisotropic elastomers. This study establishes a novel methodology for exploring fracture mechanics in 3D printed elastomers and underscores the potential of DIW in advancing the design and manufacturing of high-performance anisotropic soft materials.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3678-3688"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discrete Element Simulation on Mechanical Behavior and Fracture Evolution Mechanism of Regular Joint Rock Under Triaxial Compression","authors":"Yi-Ling Hua,&nbsp;Sheng-Qi Yang,&nbsp;Ming-Hui Cao,&nbsp;Wen-Ling Tian,&nbsp;Xiao-Shuang Li","doi":"10.1111/ffe.14692","DOIUrl":"https://doi.org/10.1111/ffe.14692","url":null,"abstract":"<div>\u0000 \u0000 <p>To investigate the mechanical and failure characteristics of jointed rock masses under external loads, this study established a three-dimensional numerical model using the discrete element method PFC (particle flow code) based on conventional triaxial tests of jointed rock samples. A novel contact assignment method was employed to enhance computational efficiency, effectively reproducing the mechanical behavior of jointed specimens. The influences of confining pressure, joint roughness coefficient, and joint dip angle on the strength and deformation properties of the rock mass were systematically examined. By integrating force chain strength analysis with crack development, the post-failure particle displacement field and internal stress distribution patterns were revealed. The numerical simulation results accurately replicated the strength and deformation characteristics of jointed specimens under triaxial loading conditions, demonstrating a significant transition in failure mechanisms with varying joint dip angles: from matrix-dominated failure to shear slip failure along the joint surface. An increase in joint roughness was found to markedly enhance the integrity of the specimen, while force chains primarily aligned along the normal direction of the joint surface. High stress concentrations observed on the joint surfaces rendered them more susceptible to failure during loading. To account for the bonding characteristics between the upper and lower rock blocks in the specimens, this study extended the Ladanyi shear strength criterion, making it more suitable for strength characterization under such bonded joint conditions.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3722-3745"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Very-High-Cycle Fatigue Performance of High-Carbon–Chromium Bearing Steel With Different Hydrogen Contents","authors":"Qu Zeng,&nbsp;Weijun Hui,&nbsp;Xuke Yao,&nbsp;Yongjian Zhang,&nbsp;Qing Yin,&nbsp;Qian Liu,&nbsp;Ye Liu,&nbsp;Xiaolin Wu","doi":"10.1111/ffe.14697","DOIUrl":"https://doi.org/10.1111/ffe.14697","url":null,"abstract":"<div>\u0000 \u0000 <p>The very-high-cycle fatigue (VHCF) behavior of a high-carbon–chromium bearing steel with different hydrogen contents was investigated using ultrasonic fatigue testing. The results show that the VHCF property of the vacuum heat–treated sample VA with 0.29 ppm H is comparable to that of the air heat–treated one NH with 0.38 ppm H, while it was significantly reduced for the electrochemically hydrogen charged sample CH with 1.69 ppm H, a decrease of fatigue strength at 10⁹ cycles by ~20%. An increase in hydrogen content exhibited noticeable influence on decreasing the size of granular bright facet (GBF), a special area around crack initiator, at identical applied stress amplitude, and the threshold values for the beginning of GBF formation and stable crack growth. A parameter taking into account the effect of hydrogen to Murakami's \u0000<span></span><math>\u0000 <msqrt>\u0000 <mtext>area</mtext>\u0000 </msqrt></math> parameter model could well estimate the fatigue strength.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3706-3721"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Influence of Initial Disturbance Values on Coal Rock Bodies Fracture Damage Under Different Soft Rock Ratios","authors":"Jianlong Wang,&nbsp;Dong Wang,&nbsp;Baoliang Li,&nbsp;Yujing Jiang,&nbsp;Huichen Xu,&nbsp;Xiubiao Jiang","doi":"10.1111/ffe.14691","DOIUrl":"https://doi.org/10.1111/ffe.14691","url":null,"abstract":"<div>\u0000 \u0000 <p>This study conducted low-frequency disturbance loading experiments on soft rock–coal combinations with different coal–rock ratios under different initial disturbance values to research the mechanical properties and fracture modes of the combinations. Research results are shown as follows: (1) As the initial disturbance value increases, the bearing capacity of combinations with varying proportions of rock also increases. (2) The acoustic emission b value of combinations exhibits significant fluctuations during both the disturbance and the pre-destruction phase, showing an opposite trend to the sudden increase and decrease in stress. And the absolute energy gradually decreases as the initial disturbance value increases during destruction. (3) The acoustic emission RA-AF results indicate that as the initial disturbance value increases, the proportion of tensile cracks in the specimen also increases. (4) The realistic failure process analysis (RFPA) numerical simulation combined with actual failure jointly demonstrates the failure and fracture behavior of the combinations.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3689-3705"},"PeriodicalIF":3.2,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the Fracture Performance of the FDM-ABS Specimens for Low-Temperature Applications","authors":"A. Teimoori,&nbsp;A. Nabavi-Kivi,&nbsp;N. Choupani,&nbsp;M. R. Ayatollahi","doi":"10.1111/ffe.14682","DOIUrl":"https://doi.org/10.1111/ffe.14682","url":null,"abstract":"<p>Fused deposition modeling (FDM) represents a subcategory of additive manufacturing that encompasses different manufacturing parameters, which significantly influence the mechanical performance of printed components. Moreover, FDM-produced parts may be subjected to various temperature conditions across various industrial applications. In this study, acrylonitrile butadiene styrene (ABS) FDM specimens were printed with three distinct layer orientations and conditioned at temperatures of −20°C, −10°C, 0°C, and 25°C for 12 h. Tensile and mode I fracture experiments were conducted, revealing an increase in elastic modulus at lower temperatures. At 0°C, the fracture resistance was found to be 12.1, 18.6, and 6 kJ/m² for flat, on-edge, and upright layer orientations, respectively. Besides, the fracture properties of the tested parts were calibrated for future fracture predictions considering various modes of loading. The fracture surfaces of tensile specimens were subsequently examined via scanning electron microscopy (SEM) to clarify the underlying fracture mechanisms. Fractographic analysis primarily identified irregular patterns and stair–step features, which related to the energy absorption process and interlayer resistance against the failure. Higher amounts of ridge markings were observed in the 0°C conditional temperature, which annotated higher plastic deformations during the tensile loading condition. The SEM results were in accordance with the tensile mechanical properties.</p>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3662-3677"},"PeriodicalIF":3.2,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ffe.14682","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144774072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Statistical Review of Hydrogen Effects on the Fatigue and Fracture Behavior of Steel","authors":"H. Wang,&nbsp;N. O. Larrosa,&nbsp;D. Engelberg,&nbsp;R. Best,&nbsp;L. Susmel","doi":"10.1111/ffe.14687","DOIUrl":"https://doi.org/10.1111/ffe.14687","url":null,"abstract":"<p>This study conducts a statistical re-analysis of experimental data from the literature to assess the influence of hydrogen on key mechanical properties, including the medium-/high-cycle fatigue strength and the threshold value of the stress intensity factor range. The analysis employs linear regression, S-N curve plotting, and Paris' law regression. The results indicate that hydrogen has a minimal effect on the endurance limit of steel (estimated at \u0000<span></span><math>\u0000 <mn>2</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>6</mn>\u0000 </msup></math> cycles to failure), in contrast to the reductions in lifespan observed in the medium-cycle fatigue regime. Regarding crack propagation, the threshold value of the stress intensity factor range is reduced in the presence of hydrogen, particularly in conventional steel, which is more susceptible to hydrogen embrittlement than stainless steel. Conversely, systematic evaluation of constants linked to Paris' equation across various material types revealed considerable variability, suggesting a non-discernible trend in the response to hydrogen.</p>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3613-3644"},"PeriodicalIF":3.2,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ffe.14687","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Nonlinear Fatigue Cumulative Damage Model Based on Enhanced Whale Optimization Algorithm and Manson–Halford Model","authors":"Yuhan Tang,&nbsp;Yuedong Wang,&nbsp;Qi Dong,&nbsp;Yonghua Li,&nbsp;Tao Guo,&nbsp;Zhiyang Zhang","doi":"10.1111/ffe.14689","DOIUrl":"https://doi.org/10.1111/ffe.14689","url":null,"abstract":"<div>\u0000 \u0000 <p>In the field of modern mechanical engineering, structures often endure multi-level variable stress loading. The nonlinear fatigue cumulative damage process of these structures is highly complex due to the significant influence of loading sequences and interactions, which makes fatigue life prediction difficult. To accurately describe the impacts of these factors on fatigue damage, this paper proposes a nonlinear fatigue cumulative damage model (EWOA-MH) based on the enhanced whale optimization algorithm (EWOA) and the Manson–Halford (M-H) model. This model obtains weight factors through EWOA and incorporates them into the M-H model. Verified by experimental data of multi-level variable stress loading and calculated with a weighted method considering different materials' sample numbers, the prediction accuracy is increased by approximately 43%. Its application to the analysis of high-speed train bogie frames effectively demonstrates the model's effectiveness. The research shows that the EWOA-MH model performs outstandingly in fatigue life prediction and can effectively solve fatigue damage problems under multi-level variable stress loading conditions.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 8","pages":"3528-3544"},"PeriodicalIF":3.1,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trustworthy Contextual Neural Networks for Deciphering Fracture in Metals","authors":"Dharanidharan Arumugam,&nbsp;Ravi Kiran","doi":"10.1111/ffe.14686","DOIUrl":"https://doi.org/10.1111/ffe.14686","url":null,"abstract":"<div>\u0000 \u0000 <p>A novel approach was proposed and implemented to assess the confidence of the individual class predictions made by convolutional neural networks trained to identify the type of fracture in metals. This approach involves utilizing contextual evidence in the form of contextual fracture images and contextual scores, which serve as indicators for determining the certainty of the predictions. This approach was first tested on both shallow and deep convolutional neural networks employing four publicly available image datasets: MNIST, EMNIST, FMNIST, and CIFAR10, and subsequently validated on an in-house steel fracture dataset—FRAC, containing ductile and brittle fracture images. The effectiveness of the method is validated by producing contextual images and scores for the fracture image data and other image datasets to assess the confidence of selected predictions from the datasets. The CIFAR-10 dataset yielded the lowest mean contextual score of 78 for the shallow model, with over 50% of representative test instances receiving a score below 90, indicating lower confidence in the model's predictions. In contrast, the CNN model used for the fracture dataset achieved a mean contextual score of 99, with 0% of representative test instances receiving a score below 90, suggesting a high level of confidence in its predictions. This approach enhances the interpretability of trained convolutional neural networks and provides greater insight into the confidence of their outputs.</p>\u0000 </div>","PeriodicalId":12298,"journal":{"name":"Fatigue & Fracture of Engineering Materials & Structures","volume":"48 9","pages":"3645-3661"},"PeriodicalIF":3.2,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144774063","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}