Theoretical and Applied Fracture Mechanics最新文献

{"title":"Mixed-mode I/II fracture investigation of 3D printed poly ether ether ketone (PEEK)","authors":"Gaurav Sharma ,&nbsp;Amol Vuppuluri ,&nbsp;Anirudh Udupa ,&nbsp;Kurra Suresh","doi":"10.1016/j.tafmec.2025.104854","DOIUrl":"10.1016/j.tafmec.2025.104854","url":null,"abstract":"<div><div>3D printed PEEK components are now routinely utilized in dental, automotive, and aerospace sectors as PEEK can potentially replace metals. However, a correct evaluation of the fracture behavior and structural integrity especially under mixed-mode loading situations is highly desired to avail the benefits of 3D printed PEEK structures fully. In the present study, the mixed-mode I/II fracture response of additively manufactured PEEK thin sheets is explored using the essential work of fracture (EWF) approach. The length of the actual fracture process zone is incorporated into the mathematical formulation of the EWF approach for the first time to assess the mixed-mode fracture phenomena accurately. The<!--> <!-->mode-mixity<!--> <!-->of loading is introduced by varying the orientations of the pre-cracks in 3D printed PEEK specimens. We found that both the essential work of fracture w_e and the plastic dissipation w_p increased monotonically with the pre-crack angle. This indicates that the mixed-mode fracture toughness is substantially greater than the Mode-I toughness. Furthermore, the tendency of the pre-cracks to deviate from the notch-plane was characterized by ex-situ microscopy. The fractured surfaces of 3D-printed cracked specimens are also investigated to recognize the potential mixed-mode failure mechanisms. The observations and analyses presented in this study provide necessary directives for evaluating the strength and longevity of additively manufactured PEEK components.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104854"},"PeriodicalIF":5.0,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface to the special issue of Theoretical and applied fracture mechanics - fatigue crack growth - multiscale modelling and crack path analysis in engineering materials","authors":"Stanislav Seitl (Guest editor) ,&nbsp;Jiří Man (Guest editor) ,&nbsp;Michal Jambor (Guest editor)","doi":"10.1016/j.tafmec.2025.104860","DOIUrl":"10.1016/j.tafmec.2025.104860","url":null,"abstract":"","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104860"},"PeriodicalIF":5.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic phase-field model for fracture analysis of thin fiber-reinforced composites","authors":"Hao-Jie Wang,&nbsp;Jing-Fen Chen","doi":"10.1016/j.tafmec.2025.104855","DOIUrl":"10.1016/j.tafmec.2025.104855","url":null,"abstract":"<div><div>In this work, an anisotropic phase-field model (PFM) which is able to combine various damage initiation criteria is developed for the fracture analysis of thin fiber-reinforced composites. In order to prevent the unrealistic contribution of the fiber/matrix driving force to the failure of the matrix/fiber, two activation parameters are introduced in the crack driving force to determine the damage initiations of both the fiber and matrix, respectively. To improve computational efficiency and alleviate convergence difficulties, explicit time integration rules are adopted to solve the nonlinear governing equations. The present model is implemented in the finite element procedure ABAQUS through the user-defined element subroutine VUEL, and the efficiency of the present model is verified by the fracture analysis of unidirectional composite laminates. The predicted results agree well with the experimental and other numerical results reported in the literature. In addition, the necessity of separately introducing two activation parameters for fiber and matrix failure in the present phase-field model is investigated.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104855"},"PeriodicalIF":5.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential evolution of the anisotropic fracture characteristics of laminated rock under monotonic and fatigue loading","authors":"Cunbao Li,&nbsp;Yanshao Deng,&nbsp;Heping Xie,&nbsp;Peng Chu,&nbsp;Yifei Liu","doi":"10.1016/j.tafmec.2025.104859","DOIUrl":"10.1016/j.tafmec.2025.104859","url":null,"abstract":"<div><div>To study the difference anisotropic fracture evolution of laminated rock between monotonic loading and fatigue loading, this study conducts three-point bending and real-time digital image correlation (DIC) monitoring tests on shale with 7 different bedding orientations under these two different loading paths. DIC is used to analyze the anisotropic horizontal and shear strain fields, crack dominant parameters (CDP), crack tip opening displacement (CTOP), and fracture process zone (FPZ) characteristics. The results indicate that the peak load is generally lower under fatigue loading than under monotonic loading, and the difference becomes more pronounced as the bedding angle increases. Under fatigue loading, the load–displacement curve has four stages: the elastic, stable microcrack evolution, unstable microcrack evolution, and failure stages. Three stages are observed under monotonic loading without obvious unstable microcrack evolution stages. The CDP values are smaller under fatigue loading than under monotonic loading, indicating that shear stress has a more pronounced effect on crack evolution under fatigue loading, and the shale samples are more prone to tensile-shear failure. The CTOD shows anisotropic characteristics influenced by the bedding angle. The variance of CTOD values measured for seven bedding angle specimens under monotonic load is 2.68, while it is 2.94 under fatigue load. The average length and width of the FPZ under fatigue loading are 1.2 to 1.3 times greater than those under monotonic loading, resulting in a larger damage zone. Under fatigue loading, the bedding structure accelerates the formation of microcracks and the anisotropy of shale mechanical behavior is more pronounced. This is because damage accumulates gradually with increasing load during monotonic loading, while repeated loading and unloading in fatigue loading results in significantly more cracks and crack expansion propagation.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104859"},"PeriodicalIF":5.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the mixed-mode creep crack growth behavior of GH4169 superalloy: Experimental and numerical approaches","authors":"Xin Huang ,&nbsp;Hongyu Qi ,&nbsp;Shaolin Li ,&nbsp;Qikun Xie ,&nbsp;Xiaoguang Yang ,&nbsp;Duoqi Shi","doi":"10.1016/j.tafmec.2025.104852","DOIUrl":"10.1016/j.tafmec.2025.104852","url":null,"abstract":"<div><div>Time-dependent fracture mechanics primarily addresses creep crack growth (CCG) in creep-ductile materials. However, certain superalloys exhibit creep-brittle behavior, where CCG rates are governed by <em>K</em>. In this study, the mode I and I/II mixed mode CCG behavior of the superalloy GH4169 at 550 °C were investigated using experimental and numerical methods. Scanning electron microscope observations showed that intergranular fracture dominated the initial and stable crack growth stages. Finite element analysis indicated that the crack tip remained small scale creep and predominantly exhibited mode I behavior once crack growth initiated. For various loading angles, the d<em>a</em>/d<em>t</em>-<em>K</em>_I curves aligned along a single line. The crack growth angle, predicted by MTS theory, showed good agreement with experimental results. Additionally, FRANC3D software was used to simulate the CCG behavior.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104852"},"PeriodicalIF":5.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of mixed-mode crack propagation in Mindlin plates by a hierarchical quadrature element method with minimal remeshing","authors":"Sihua Hu ,&nbsp;Lisong Tan ,&nbsp;Bo Liu ,&nbsp;Wei Xiang","doi":"10.1016/j.tafmec.2025.104853","DOIUrl":"10.1016/j.tafmec.2025.104853","url":null,"abstract":"<div><div>In this work, a framework for efficient and automatic crack propagation simulation in Mindlin plates is established, utilizing the hierarchical quadrature element method (HQEM) characterized by <em>p</em>-convergence. The HQEM is combined with the virtual crack closure method to extract mixed-mode moment and shear force intensity factors of cracked Mindlin plates. These fracture parameters are employed to predict the crack propagation direction according to the maximum circumferential tensile stress criterion. A notable advantage of HQEM over conventional <em>h</em>-version FEM is its capacity to achieve highly accurate fracture parameters with a rather coarse mesh. To take advantage of the simplicity of HQEM in pre-processing, a minimal remeshing strategy utilizing NURBS fitting for crack paths is developed. This strategy maintains a minimal or even constant number of elements throughout the crack propagation process, significantly reducing the workload associated with mesh regeneration while preserving the accuracy of fracture parameters and crack propagation paths.</div><div>The practicality and accuracy of the proposed method are verified through several numerical examples involving a variety of crack configurations, including both infinite and finite geometries, as well as pure mode and mixed mode scenarios. The results for fracture parameters and crack propagation paths align closely with those reported in the literature. This consistency strongly indicates that the proposed method is a promising numerical tool for efficient and reliable crack propagation analysis.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104853"},"PeriodicalIF":5.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the effects of hydrogen trapping on hydrogen environment-assisted cracking of vanadium-added steels","authors":"Gabriel Vanni ,&nbsp;Leonardo Simoni ,&nbsp;Tárique H. Schneider ,&nbsp;Henrique R.P. Cardoso ,&nbsp;Rômulo F.G Rigoni ,&nbsp;Daniel C.F. Ferreira ,&nbsp;Adriano Scheid ,&nbsp;Carlos E.F. Kwietniewski","doi":"10.1016/j.tafmec.2025.104851","DOIUrl":"10.1016/j.tafmec.2025.104851","url":null,"abstract":"<div><div>Current standards and technical specifications typically limit the maximum hardness of steels under subsea cathodic protection. However, hydrogen trapping has recently gained attention for mitigating hydrogen embrittlement. This study investigates the potential of hydrogen trapping to enhance hydrogen environment-assisted cracking (HEAC) resistance of vanadium-added steels under cathodic protection conditions. The investigation includes nano/microstructural characterization, electrochemical hydrogen permeation, and thermal desorption analyses. HEAC resistance is evaluated through fracture toughness tests under cathodic polarization. AISI<!--> <!-->4330 <!--> <!-->V steel is evaluated at both acceptable and higher hardness levels than those allowed by current standards. Additionally, a modified version of a similar steel designed to enhance hydrogen trapping is studied. Hydrogen trapping is mainly related to the presence of carbides in each alloy. Even though the types and characteristics of carbides differ among steels, the de-trapping activation energy is not significantly altered. Instead, the primary factor influencing the hydrogen trapping behavior is the density of traps. Although steels with hardness levels higher than accepted standards exhibited larger trapping capacity, it does not necessarily result in enhanced the HEAC resistance. For the materials considered here, fracture toughness is not enhanced by a higher trapping capacity when materials with similar hardness level are tested under cathodic protection conditions at –1,100<!--> <!-->mV_SCE. At this potential, HELP + HEDE mechanisms are evident for the lower hardness condition, while HEDE mechanism is observed for the higher hardness level. Nevertheless, at less negative potentials (−900 and –780<!--> <!-->mV_SCE), the steel trapping ability can account for increased HEAC resistance and a transition from HEDE to HELP + HEDE mechanisms.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104851"},"PeriodicalIF":5.0,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliability-based approach for structural integrity assessment of a bucket wheel excavator","authors":"Ana Petrović ,&nbsp;Nikola Momčilović ,&nbsp;Aleksandar Sedmak ,&nbsp;Branislav Đorđević ,&nbsp;Dorin Radu ,&nbsp;Vesna Milošević-Mitić ,&nbsp;Aleksandar Bogojević","doi":"10.1016/j.tafmec.2025.104849","DOIUrl":"10.1016/j.tafmec.2025.104849","url":null,"abstract":"<div><div>Existing studies dealing with structural strength of bucket wheel excavators (BWE) include a traditional approach that does not take into account the whole structural response of the object, but only considers the maximum response at the single location. To solve this issue, this paper proposes assessment of the structural response of BWE SchRs 630 that separates structural from mechanical failures, and predicts the reliability of the design. Firstly, stress results from finite element analysis for different loading scenarios are obtained. Three loading scenarios are included: (i) working load and steel weight (deadweight); (ii) steel weight; (iii) steel weight and inertial forces induced by slew drive breaking. In that way the whole in-service cycle of the BWE would be covered. Stresses and the yield criteria are treated as random variables in order to produce their probability density functions, which are compared to evaluate structural response. Monte Carlo method is used for the calculation of the structure’s probability of failure and consequently, reliability and reliability index. That means that the whole structure response is described using one single value − probability of failure. Also, the analysis has shown that the probability of failure starts to rise more rapidly for the reduction factor (RF) below the 0.6–0.7 range. This study confirms design code recommendation value for the criterion of yield stress limit reduction factor RF = 0.67. In addition, assessment of potential cracks was performed to obtain overall structural integrity assessment (OSIA) of the structure. Based on those results, reliability can be increased by small local improvements.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104849"},"PeriodicalIF":5.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of crack initiation competition and interaction of cross flaw on the dynamic fracture behavior of granite under biaxial compression","authors":"Tingting Liu ,&nbsp;Luyang Ding ,&nbsp;Hui Shen ,&nbsp;Chang Xiang ,&nbsp;Shenghao Yang","doi":"10.1016/j.tafmec.2025.104850","DOIUrl":"10.1016/j.tafmec.2025.104850","url":null,"abstract":"<div><div>Flawed rock mass may exhibit complex fracture behavior when subjected to dynamic loads such as blasting or earthquakes. Therefore, understanding the fracture mechanism of rock mass with non-persistent cross flaws under in-situ stress is vital for ensuring safe construction and prolonged operation of deep geotechnical engineering. In this study, dynamic tests under biaxial static loading were conducted with consideration of the effect of the flaw persistency ratio. The fracture toughness was calculated from the digital image correlation (DIC) results to analyze the intrinsic fracture mechanism, failure mode, and microscopic damage morphology. The findings reveal the failure mode of the fractured rock mass has a predictable evolution process according to the spatial geometric characteristics of the cross flaws. At the moment of crack initiation, the stress intensity factor (SIF) value of mode-Ⅰ crack at the main flaw tip is considerably greater than that of the secondary flaw tip. In the crack propagation stage, the stress fields of the second flaw tips of the specimen with different persistency ratios exhibit disparate responses to the fracture behavior of the main flaw tip. Microcracks tend to aggregate at the ends of typical shear failure zones under tensile-shear stress. The obtained results can provide a useful reference for the safe construction of underground engineering.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104850"},"PeriodicalIF":5.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toughening of concrete with ductile cementitious matrix: Proof of concept","authors":"Duo Zhang ,&nbsp;Junsheng Li","doi":"10.1016/j.tafmec.2025.104847","DOIUrl":"10.1016/j.tafmec.2025.104847","url":null,"abstract":"<div><div>Fiber-reinforced concrete (FRC) is typically formulated by adding fibers to an existing concrete mixture. This limits the toughening potential, as fibers located away from the main crack tend to be underutilized. Here, we report a new composite system featuring non-close-packed coarse aggregates randomly embedded in a ductile fiber-reinforced cementitious mortar. The scientific objective is to validate the hypothesis that by prioritizing the ductility design of the mortar matrix, we can improve the fracture resistance of FRC while maintaining a constant fiber volume. For this purpose, both notched and unnotched beams were tested, and the damage patterns were evaluated by ultrasonics and surface crack observations. Our results reveal a simultaneous improvement of flexural strength and toughness, arising from an extended strain-hardening stage passing the first peak load. This contributes to an enhanced fracture resistance at small strains and limits the main crack propagation. Through crack and ultrasonic measurements, we confirm the existence of multiple crack branching, which raises the off-crack-plane energy in the ductile matrix. These preliminary findings could pave the way for a new toughening strategy in the design of FRC, focusing on enhancing the efficiency of fiber utilization through the ductility design of the mortar matrix.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104847"},"PeriodicalIF":5.0,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}