Theoretical and Applied Fracture Mechanics最新文献

{"title":"Assessment of full-field J-integrals through digital image correlation using stress estimation based on measured strains","authors":"Antti Forsström ,&nbsp;Juha Kuutti ,&nbsp;Bruno Reinaldo Goncalves ,&nbsp;Sebastian Lindqvist","doi":"10.1016/j.tafmec.2025.105064","DOIUrl":"10.1016/j.tafmec.2025.105064","url":null,"abstract":"<div><div>Application of digital image correlation (DIC) for full-field <em>J</em>-integral measurement with single-edge bending type SE(B) specimens, varying crack length-to-width ratios (<em>a₀</em>/W), and a ductile material was studied numerically and experimentally. The specimens were first modelled in FEM and the displacement data was treated as measurement data to validate the method. Experimental studies were then conducted to extract full-field <em>J</em>-integrals by DIC. The study shows comparable or slightly higher <em>J</em>-values obtained with the surface DIC measurement as with the ASTM E1820 standard. However, there are certain considerations regarding convergence of the full-field <em>J</em>-integrals when large scale yielding and large rotations are involved.</div><div>The small strain theory behind <em>J</em>-integral imposes a limitation on the full-field method once the rotations are large enough to impose an error in the measured gradients. The rotations cause an inherent negative error in the measured gradients, which in turn imposes a negative error in the measured <em>J</em>. This is especially evident when the contour or domain for <em>J</em>-integral is taken far-field and contains areas that exhibit close to zero strains. A simple remedy is to determine the <em>J</em>-integral relatively close to the crack tip avoiding large rotations, while still also avoiding the crack tip to avoid strain localizations.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105064"},"PeriodicalIF":5.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501769","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":"Fracture behavior and deterioration mechanisms of hydraulic concrete under wet-dry cycles with variable temperature","authors":"XuanYi Zhu ,&nbsp;DongJian Zheng ,&nbsp;Yanan Zhang ,&nbsp;XuDong Chen ,&nbsp;Linze Chen","doi":"10.1016/j.tafmec.2025.105061","DOIUrl":"10.1016/j.tafmec.2025.105061","url":null,"abstract":"<div><div>Photovoltaic pumped storage power plants, as a kind of green low-carbon, flexible and adjustable power source with potential for large-scale development, are often affected by environmental factors such as variable temperature and wet/dry cycling during operation, which leads to the degradation of the mechanical properties of the panels and thus affects the structural stability. In this study, wet and dry cyclic concrete specimens were prepared by simulating a 12-hour cycle of high temperature drop (80 °C → 20 °C) conditions in a homemade test chamber. The damage mechanism of the fracture resistance of deteriorated concrete and the crack extension process were investigated by using three-point bending test combined with acoustic emission multiparameter monitoring technique. The experimental results show that the fracture instability load of the deteriorated material decreases gradually and the double-k fracture parameters change significantly; the average crack initiation toughness decreases by 44.02 % and the average instability toughness decreases by 20.39 %. The proportion of shear components in the fracture process increased from 17.1 % to 26.6 % with the increase in the number of cycles. The crack extension path shows a shift from aggregate penetration to interface bypassing, and exhibits random extension of microcracks, spatial non-homogeneity, and local energy aggregation effect triggered by the synergistic effect of multiple factors. This study provides a theoretical basis for the stability of concrete structures in pumped storage power stations.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105061"},"PeriodicalIF":5.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491798","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":"Energy–Evolution behaviour of fractured granite under triaxial loading and unloading at high confining pressure","authors":"Hao Hu ,&nbsp;Xinping Li ,&nbsp;Junhong Huang ,&nbsp;Tengsheng Zhang ,&nbsp;Zixu Wang ,&nbsp;Yi Luo ,&nbsp;Tingting Liu","doi":"10.1016/j.tafmec.2025.105062","DOIUrl":"10.1016/j.tafmec.2025.105062","url":null,"abstract":"<div><div>Abrupt changes in stress conditions during deep underground excavation can trigger sudden instability in rock masses, posing unpredictable threats to construction safety. To identify precursors of such failure, this study conducted triaxial tests on granite specimens containing prefabricated fractures. One group was continuously loaded to failure, while the other group was unloaded after reaching 75 % of peak strength. Acoustic emission (AE) signals were recorded throughout each test, while external work, elastic strain energy, and dissipated energy were calculated from stress–strain data. Shannon entropy was then introduced to analyze, from another perspective, the evolution of AE energy-level distributions during crack propagation. Results indicate that: (1) Under identical confining pressure, the unloading path induces significantly more sudden and violent failure than loading, with peak AE count rates and cumulative energy approximately one order of magnitude greater during unloading. (2) The entropy curve exhibits a sudden change earlier than the cumulative-energy curve, that means a smaller “warning strain” and can provide additional time for preventive measures. (3) The fracture dip angle has a significant impact on both specimen strength and failure precursors. A dip angle of 60°is the most unfavorable, showing the lowest strength under both loading and unloading paths, and the smallest warning strain under unloading path.This study demonstrates that integrating Shannon entropy with traditional AE-energy parameters provides earlier and more reliable precursor signals under extreme conditions, such as high confining-pressure unloading. The proposed entropy–energy joint criterion thus offers a robust physical foundation and practical method for predicting deep-rockburst hazards and assessing rock-mass stability.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105062"},"PeriodicalIF":5.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501770","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":"Prediction of fatigue crack propagation life of welded joints considering three-dimensional undercut characteristics","authors":"Sheng Chen ,&nbsp;Suming Xie ,&nbsp;Tao Li ,&nbsp;Jian Wang","doi":"10.1016/j.tafmec.2025.105056","DOIUrl":"10.1016/j.tafmec.2025.105056","url":null,"abstract":"<div><div>This study investigated the correlation between three-dimensional undercut and fatigue crack propagation life based on numerical models. The fatigue crack growth rate tests of the base metal and heat-affected zone of Q450NQR1 steel under different stress ratios were carried out to obtain the required parameters. The results show that the fatigue strength of the welded joint decreases with increasing undercut depth or decreasing undercut aspect ratio. However, the influence of the undercut radius is limited within the range of 0.05–0.1 for the undercut aspect ratio. The empirical equations for predicting the fatigue limit and fatigue life of joints with three-dimensional undercuts were further proposed. It can account for the size effect, material difference, stress ratio, and probability of survival. Comparison with the fatigue test results confirmed their acceptable prediction accuracy. In engineering practice, the equations were directly applied to establish the undercut tolerances for various welded joint types.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105056"},"PeriodicalIF":5.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501768","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":"A simulation algorithm for crack propagation in rocks subjected to frost swelling pressure","authors":"Manman Liu ,&nbsp;Fangtong Wang","doi":"10.1016/j.tafmec.2025.105059","DOIUrl":"10.1016/j.tafmec.2025.105059","url":null,"abstract":"<div><div>The crack propagation inside rocks subjected to frost swelling pressure is one of the main factors threatening the safety of rock engineering. The existing frost crack simulation algorithms are difficult to model the real shapes of cracks, and most of them are limited to the sample scale. Therefore, a novel algorithm for simulating crack propagation in rocks under frost swelling pressure is proposed. The proposed algorithm can generate frost cracks with realistic morphology and is applicable to rocks at multiple scales. The stress concentration effect is involved to simulate frost cracks in a two-dimensional plane based on Griffith criterion. The Minkowski function is employed to quantify the impact of various factors on frost cracks, including the number of freeze–thaw cycles, initial crack, and the boundary condition of the computational domain. Moreover, the coordinate information of the generated cracks can be extracted to establish the fractured rock model in numerical simulation software. The algorithm has been extended to various scales to explore the impact of frost cracks on the deformation properties of rock samples and slope stability. The proposed algorithm can clarify the evolution process of frost cracks, providing references for evaluating the safety of rock engineering.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105059"},"PeriodicalIF":5.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480818","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":"Using sand 3D printing, digital image processing technology and DEM to investigate rock hole-fissure interaction mechanisms","authors":"Zhenyu Zhu ,&nbsp;Mengyao Jiang ,&nbsp;Shuyang Yu ,&nbsp;Yifei Li","doi":"10.1016/j.tafmec.2025.105058","DOIUrl":"10.1016/j.tafmec.2025.105058","url":null,"abstract":"<div><div>Holes and fissures in rocks significantly influence rock engineering stability. This study employed sand 3D printing to create specimens with various hole-fissure combinations. Uniaxial compression tests were conducted, and DIC and DEM were used to analyze crack propagation. Results showed that seven crack types were identified. The single hole-fissure specimen had the highest peak strength, while in double hole-fissure specimens, peak strength increased with larger vertical hole distance <em>d</em> and fissure angle <em>α</em>. The number of cracks was inversely proportional to peak strength, decreasing as <em>d</em> increased and dropping sharply when <em>α</em> ranged from 30° to 60°. Crack initiation mechanisms under different circumstances were discussed. The research findings can provide valuable insights for accurately understanding the fracture mechanisms of rock masses containing hole-fissure combination structures and serve as a reference for predicting and preventing rock engineering disasters. Meanwhile, the research comprehensively adopted sand 3D printing, DIC technology and DEM to study the hole-fissure interaction mechanisms, providing a new method to efficiently study the mechanisms of rock failure.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105058"},"PeriodicalIF":5.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491799","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":"Crack propagation mechanisms in plain woven CFRP: A focus on intralaminar fracture under mixed-mode loading","authors":"Felipe Ruivo Fuga ,&nbsp;Francisco Maciel Monticeli ,&nbsp;Maurício Vicente Donadon ,&nbsp;Geraldo Maurício Cândido","doi":"10.1016/j.tafmec.2025.105039","DOIUrl":"10.1016/j.tafmec.2025.105039","url":null,"abstract":"<div><div>The design of damage-tolerant aeronautical composite structures often involves thin-walled components that are susceptible to in-plane mixed-mode fracture. Unlike with metals, this process is complicated by the composites anisotropy and the lack of standardized procedures for predicting failure in notched, holed or cracked composites under mixed-mode loading. This study introduces a novel Modified Arcan Fixture (MAF) for testing Compact Tension Shear (CTS) specimens of carbon fibre woven reinforced polymer composite. Digital Image Correlation (DIC) was used to capture strain fields and calculate Stress Intensity Factors (SIFs), which were then compared to analytical predictions for different mode combinations and notch lengths. R-curves were generated for specimens exhibiting self-similar crack propagation. The results revealed that failure modes were dominated by tensile cracking in Mode I and compressive cracking in Mode II, indicating that a single-parameter fracture criterion inadequate for the failure description. A theoretical model that incorporates both tensile and compressive cracking is proposed, which can accurately predict the complete mixed-mode fracture envelope. Furthermore, Scanning Electron Microscopy (SEM) and X-ray micro-tomography were used to elucidate the mechanisms of surface failure and the morphology of internal damage.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105039"},"PeriodicalIF":5.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365609","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":"Evaluation of dynamic fracture properties of ultra-high performance concrete: Experimental study and analytical modelling","authors":"Tian Lan,&nbsp;Shutong Yang,&nbsp;Qing Wang,&nbsp;Zhengyuan Chen,&nbsp;Yingxue Wang","doi":"10.1016/j.tafmec.2025.105055","DOIUrl":"10.1016/j.tafmec.2025.105055","url":null,"abstract":"<div><div>Although existing studies have explored the fracture behavior of ultra-high performance concrete (UHPC) under dynamic loading, traditional fracture mechanics models fail to fully consider its heterogeneity as a multiphase composite material under dynamic conditions, resulting in size-dependent fracture parameters. Additionally, current studies do not provide a consistent interpretation of size effects under dynamic conditions. To address these issues, this study proposed an analytical method based on the boundary effect model (BEM) to predict the size-independent tensile strength (<em>f</em>_t) and fracture toughness (<em>K</em>_IC) of UHPC under different loading rates combined with three-point bending fracture tests. Using the peak load (<em>F</em>_max) measured in tests, the model yielded closed-form solutions to eliminate size effects in fracture parameters, enabling a clearer understanding of the rate sensitivity of UHPC and providing a more scientific evaluation of its dynamic fracture properties. The effect of loading rate on fracture behaviors was comprehensively discussed. The results showed that the damage zone in UHPC expanded and the number of microcracks increased with increasing loading rate. As the loading rate increased from 0.02 mm/min to 200 mm/min, <em>f</em>_t increased by 34.19 %, 32.97 %, and 29.88 % for fiber volume fractions of 1 %, 2 %, and 3 %, respectively. The incorporation of an appropriate number of steel fibers significantly improved crack resistance. <em>f</em>_t of UHPC with 2 % fiber content increased by 44.46 % to 51.18 % compared to that with 1 % fiber content, but when the fiber content increased to 3 %, the enhancement effect was weakened. Moreover, with increasing fiber content, the sensitivity to loading rate decreased.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105055"},"PeriodicalIF":5.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501771","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":"Effect of geometric configuration on propagation law and fracture mechanics mechanism of rock mode-I cracks","authors":"Lexin Chen ,&nbsp;Weiyao Guo ,&nbsp;Yongsheng Zheng ,&nbsp;Xinbo Ji ,&nbsp;Ruijie Zhang ,&nbsp;Guangzhao Liu","doi":"10.1016/j.tafmec.2025.105053","DOIUrl":"10.1016/j.tafmec.2025.105053","url":null,"abstract":"<div><div>Studying the fracture behavior of rocks under different geometric configurations has important theoretical reference significance for the design of fracture mechanics experiments, the prevention and control of engineering disasters in underground rock masses, and the optimization of directional fracturing technology for coal and rock masses. In this study, four specimen types (semicircular bending (SCB), single-edge notch beam (SENB), single-crack three-point bending (SC3PB), and crack directional propagation (CDP)) were used for mode-I fracture tests to investigate the effects of different geometric configuration on the mechanisms of rock mode-I fracture mechanics. The mode-I fracture characteristics across the geometric configurations were analyzed, and the acoustic emission (AE) and deformation field evolution during crack propagation were investigated. In addition, the fracture process zone (FPZ) features and crack propagation rates were explored, revealing the geometric configuration mechanisms in the mode-I fracture. The results demonstrate that the peak fracture load and mode-I crack paths exhibited geometric dependency, with the peak fracture load and crack paths deviation decreasing in the order of the SCB, SENB, SC3PB, and CDP specimens. The AE evolution during mode-I cracking was divided into four stages, i.e., quiet, slow-increasing, booming, and decreasing periods. The SC3PB and CDP specimens exhibited shorter pre-peak energy accumulation duration but longer post-peak main crack coalescence compared with the SCB and SENB specimens. According to the deformation field evolution, the mode-I crack propagation process was divided into three stages, i.e., microcrack initiation, main crack inoculation and formation, and main crack propagation and penetration. The SCB and SENB specimens demonstrated significantly higher maximum deformation than the SC3PB and CDP specimens, which indicates stronger crack tip deformation. The average crack propagation rate was higher in the SCB and SENB specimens than in the SC3PB and CDP specimens, resulting in an increase in shear cracks and energy consumption during crack propagation. which reduced the crack propagation stability and greater deviation.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105053"},"PeriodicalIF":5.0,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365608","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":"Inflection point principle combined with digital image correlation and machine learning for crack length measurement in fatigue tests","authors":"Bořek Ščerba ,&nbsp;Tomáš Adamec ,&nbsp;Pavel Pokorný ,&nbsp;Tomáš Návrat ,&nbsp;Michal Vajdák ,&nbsp;Luboš Náhlík","doi":"10.1016/j.tafmec.2025.105052","DOIUrl":"10.1016/j.tafmec.2025.105052","url":null,"abstract":"<div><div>The visual inspection method is a widely used non-contact technique for measuring fatigue crack propagation, but it is inefficient, requiring frequent operator input. Digital image correlation (DIC) methods provide alternatives. However, full-field methods are computationally demanding, while line-based thresholding techniques are sensitive to material load conditions, reducing consistency. This study proposes and validates a new non-contact, physically-based method for real-time crack length evaluation. It eliminates the need for thresholding and enables higher testing frequencies due to its line-based nature, supporting accurate, versatile, and automated fatigue testing. The method integrates the inflection point principle with DIC and machine learning. Visual inspection serves as a validation baseline, using a novel setup that applies both methods simultaneously on the same side of the sample for direct comparison. The proposed method shows good agreement with baseline results, achieving mean absolute errors of 24 μm (static) and 54 μm (dynamic). Compared to line-based thresholding, it is four times more accurate (dynamic) and independent of load levels, though 1.7 times slower.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105052"},"PeriodicalIF":5.0,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470033","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}