Theoretical and Applied Fracture Mechanics最新文献

{"title":"Fatigue crack growth analysis in CTS specimens made of railway wheel steel under mixed-mode loading conditions","authors":"Reza Masoudi Nejad ,&nbsp;Farzaneh Samadi","doi":"10.1016/j.tafmec.2025.105097","DOIUrl":"10.1016/j.tafmec.2025.105097","url":null,"abstract":"<div><div>This study presents a detailed experimental and analytical investigation into the fatigue crack growth behavior of a hypoeutectoid pearlitic railway wheel steel under mixed-mode loading. Compact Tension Shear (CTS) specimens with radial and tangential notch orientations were tested to characterize crack path evolution, stiffness variations, and closure behavior. The tests were conducted under controlled loading angles to simulate mixed-mode fracture conditions, and crack closure effects were quantified using load–Crack Mouth Opening Displacement (CMOD) analysis and stiffness degradation metrics. A modified non-linear Kujawski-Ellyin (KE) model incorporating the Rigid Insert Crack Closure (RICC) concept and CMOD-Compliance Closure Assessment (CCCA) was employed to predict fatigue life. The experimental results demonstrated notable differences in fatigue performance based on notch orientation and loading angle, with tangentially notched specimens exhibiting enhanced life at lower loading angles. Analytical predictions showed strong agreement with experimental data, validating the adopted model. The findings provide new insights into fatigue crack driving forces under shear-dominant mixed-mode conditions and offer a robust framework for fatigue life assessment in critical railway components.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105097"},"PeriodicalIF":5.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663339","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":"Research on fracture toughness of X80 pipeline girth welds based on quantitative assessment of fractal characteristics of fracture surfaces","authors":"Liu Xingfeng ,&nbsp;Liu Yuqiu ,&nbsp;Zhen Ying ,&nbsp;Xu Yongxin ,&nbsp;Chen Jian ,&nbsp;Wu Guiyi ,&nbsp;Cao Yuguang","doi":"10.1016/j.tafmec.2025.105098","DOIUrl":"10.1016/j.tafmec.2025.105098","url":null,"abstract":"<div><div>With the rapid development of high-grade long-distance pipeline engineering, circumferential weld failure has progressively become a critical factor affecting pipeline service reliability. While classical fracture-mechanics-based failure analysis already relates measured fracture toughness to applied stress-intensity fields, flaw size and microstructure, a widely accepted quantitative framework that links explicit three-dimensional fracture-surface-roughness descriptors (e.g., root-mean-square height or fractal dimension) with toughness is still lacking and therefore constitutes the focus of this study. To address this research gap, we systematically evaluate the fracture toughness of the single X80 pipeline girth weld investigated in this study by applying fractal analysis to its fracture-surface topography. The research methodology involved three key phases: First, fracture toughness parameters of base metal (BM), heat-affected zone (HAZ), and weld metal (WM) were obtained through three-point bending tests. Subsequently, high-precision three-dimensional reconstruction of fracture surfaces was performed using laser scanning technology to extract and analyze morphological characteristics across different regions. Finally, the box-counting method was employed to calculate fractal dimensions of fracture surfaces, enabling quantitative characterization of fracture complexity and investigation of its coupling relationship with fracture toughness. Results demonstrated significant positive correlations among fracture surface fractal dimension, surface roughness, and fracture toughness. For the X80 girth weld examined in this study, the quantitative link observed between fracture-surface fractal dimension and fracture toughness suggests that fractal analysis could serve as a rapid screening tool for fracture properties; however, its applicability requires broader validation before general conclusions can be drawn.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105098"},"PeriodicalIF":5.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656407","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":"Adaptive phase-field simulation of crack propagation in brittle materials: COMSOL implementation","authors":"Jia-Nan He ,&nbsp;Tiantang Yu ,&nbsp;Hirshikesh","doi":"10.1016/j.tafmec.2025.105077","DOIUrl":"10.1016/j.tafmec.2025.105077","url":null,"abstract":"<div><div>In the phase-field model for modeling fracture, a high-resolution mesh is required to accurately capture diffused cracks, leading to high computational costs, especially in three-dimensional problems. In this work, a novel COMSOL application programming interface (API)-based adaptive phase-field method is proposed to improve computational efficiency. Due to the lack of native support in COMSOL for dynamic mesh refinement during the solution process, the code editor in the COMSOL Application Building is utilized to control adaptive mesh refinement during each loading step, and the phase-field value is selected as the indicator to achieve the automatic local refinement of the mesh. The functionality of spatial adaptivity is embedded into COMSOL for the first time. The proposed method directly leverages COMSOL’s proven and robust built-in remeshing module and eliminates the need for users to develop or understand complex mesh adaptation code, making the technique immediately accessible to researchers and engineers without specialized programming expertise in adaptive meshing. Validated by several two- and three-dimensional benchmark examples, the proposed model can efficiently simulate quasi-static and dynamic fractures without compromising on accuracy.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105077"},"PeriodicalIF":5.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656408","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":"High-resolution acoustic microscopy for assessing damage propagation in [±45] carbon fiber laminates under compression","authors":"Egor Morokov ,&nbsp;Pavel Shershak ,&nbsp;Nikolay V. Turbin ,&nbsp;Nikolay O. Kononov ,&nbsp;Aleksandr Volodarskii ,&nbsp;Vadim Levin","doi":"10.1016/j.tafmec.2025.105096","DOIUrl":"10.1016/j.tafmec.2025.105096","url":null,"abstract":"<div><div>This work presents the results of the experimental investigation of the compressive damages in the volume of angle-ply laminates with a various central ply of 0° or 90° fiber orientation. Layer-by-layer observation of volume microstructure damages was performed using high-frequency acoustic microscopy. The ultrasound imaging revealed the location of matrix cracking, fiber fracture and interlayer delaminations in laminates with [±45°₂/<span><math><mover><mrow><msup><mn>0</mn><mo>°</mo></msup></mrow><mrow><mo>¯</mo></mrow></mover></math></span>]_S and [±45°₂/<span><math><mover><mrow><msup><mn>90</mn><mo>°</mo></msup></mrow><mrow><mo>¯</mo></mrow></mover></math></span>]_S layup. Experimental results were supplemented numerical modeling of the development of the fracture process. According to the ultrasound imaging of the volumetric microstructure, we highlighted several typical damage in laminates and assumed the role of central ply in process of damage appearance and evolution in angle-ply laminates under compression. It was found that damage in laminates with a central 90° ply was predominantly multiple small-scale delaminations, united by a mesh of matrix cracks that formed during smooth plastic deformation; while the central 0° ply, on the contrary, provided rigidity of the structure, which led to the fracture of fibers and the growth of extended delaminations.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105096"},"PeriodicalIF":5.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656474","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":"Experimental study on the influence of crack number on the fracture behavior of sandstone under graded loading","authors":"Liwen Huang,&nbsp;Shan Yin,&nbsp;Zhonghui Li,&nbsp;Zihao Mao,&nbsp;Hangyu Li,&nbsp;Quancong Zhang","doi":"10.1016/j.tafmec.2025.105095","DOIUrl":"10.1016/j.tafmec.2025.105095","url":null,"abstract":"<div><div>In practical engineering, rock masses often contain natural cracks, and variations in the number of cracks during loading can significantly affect their mechanical properties. This study conducted graded loading experiments on sandstone samples with different numbers of pre-existing cracks, with simultaneous collection of Acoustic Emission (AE) and Digital Image Correlation (DIC) signals. The influence of crack number on the mechanical properties and failure behavior of sandstone was investigated, and the mechanisms governing crack propagation under graded loading were revealed. The results show that: (1) as the number of cracks increases, the stress–strain curve exhibits a dual effect of “increased ductility and reduced strength.” The stress adjustment time before the peak stress is prolonged, while the peak strength and elastic modulus show a nonlinear decline. The failure mode shifts from shear failure to tensile failure. (2) In the compaction stage, high-energy AE events significantly increase with crack number (by 239 %), while the peak AE count decreases in the failure stage. The crack tips of pre-existing cracks remain the dominant regions for microcrack nucleation, and even under 100 kN quasi-static loading, the AE event density remains concentrated around the tips of pre-existing cracks. (3) As the number of cracks increases (from 1 to 3), the formation time of localized strain bands is advanced (from 378.7 s to 192.4 s). Localized strain bands primarily expand during the loading stage, but under high load levels (100 kN), the expansion rate of these strain bands accelerates. (4) The failure process of sandstone primarily involves the nucleation of wing cracks. Based on fracture mechanics, the mechanical mechanisms of multi-crack wing fracture propagation are revealed. The findings of this study provide technical methods for further investigation into the failure behavior of defective rock masses in practical engineering applications.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105095"},"PeriodicalIF":5.0,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656409","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":"Failure behavior of jointed rock masses containing a circular hole under compressive-shear load: Insights from DIC technique","authors":"Qibin Lin ,&nbsp;Shenchen Zhang ,&nbsp;Hang Lin ,&nbsp;Ke Zhang ,&nbsp;Wenchen Fan ,&nbsp;Chao Huang ,&nbsp;Zuliang Shao ,&nbsp;Ming Lan","doi":"10.1016/j.tafmec.2025.105089","DOIUrl":"10.1016/j.tafmec.2025.105089","url":null,"abstract":"<div><div>The instability of jointed rock masses under compressive-shear loading poses significant challenges to the safety of underground engineering structures. This study investigates the crack propagation mechanism in jointed rock masses with a circular hole using compressive-shear tests and digital image correlation (DIC) analysis. Cement mortar specimens with varying joint dip angles were designed to simulate jointed rock masses. The results reveal that joint dip governs strain field evolution and failure modes: specimens with 30° and 75° joints exhibited anomalous failure stability, characterized by high-frequency displacement fluctuations and rapid strength degradation post-peak. The interaction between holes and joints reduced the bearing capacity by 38–52% compared to intact specimen, with shear stress dominating the failure process. A novel pixel evolution model was developed to quantify crack propagation process. Identified three strain evolution phases: rapid development during initial loading, gradual progression approaching peak stress, and stabilization post-failure. Three failure modes were classified based on joint dip angles: tensile-dominated fracture below 30°, hybrid tensile-shear failure between 45° and 60°, and shear-controlled rupture above 70°. DIC analysis captured displacement discontinuities at crack tips and localized strain patterns preceding macroscopic cracks. Specimens with critical joint dip angles exhibited over 70% residual strength reduction after failure, highlighting their engineering vulnerability. This research establishes a quantitative framework for predicting crack evolution in rock masses, thereby facilitating precursor identification through strain field quantification. The findings provide valuable insights into stability assessment and disaster mitigation in underground engineering projects.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105089"},"PeriodicalIF":5.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656403","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 mechanisms of low temperature on fracture toughness of coal with different water contents","authors":"He Zhang ,&nbsp;Jishi Geng ,&nbsp;Qiang Sun ,&nbsp;Hailiang Jia ,&nbsp;Menghao Li ,&nbsp;Shibo Li ,&nbsp;Junfang Dai","doi":"10.1016/j.tafmec.2025.105093","DOIUrl":"10.1016/j.tafmec.2025.105093","url":null,"abstract":"<div><div>Open-pit mining is a crucial extraction method in the coal industry. Coal mines located in high-latitude and high-altitude regions are often subjected to freezing conditions, which alter coal seam strength and affect slope stability. To clarify the fracture toughness behavior of coal under frozen conditions, this study conducted mode I fracture tests on coal samples with varying water contents under different low-temperature environments. By analyzing fracture parameters, surface deformation characteristics, and reviewing previous research, the following conclusions were drawn. First, higher water content and lower temperatures significantly enhance the fracture toughness of coal. During fracture, deformation becomes more concentrated in the central region, crack propagation accelerates, and greater energy is accumulated. Second, temperature influences fracture toughness by modifying the strength of internal ice and the properties of the ice–coal interface. Finally, higher moisture content results in greater ice filling at pore tips after freezing, increasing local crack angles and dispersing stress, thereby further improving overall fracture toughness. These findings offer valuable theoretical insights for improving safety in open-pit coal mining operations under cold-region conditions.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105093"},"PeriodicalIF":5.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656476","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":"Shear fracture behavior in dolomite: The interplay of thermal cycles and confining pressure","authors":"Mahmoud Alneasan ,&nbsp;Abdel Kareem Alzo’ubi","doi":"10.1016/j.tafmec.2025.105091","DOIUrl":"10.1016/j.tafmec.2025.105091","url":null,"abstract":"<div><div>Understanding the influence of temperature fluctuations and confining pressure on shear fracture behavior is essential for predicting the stability of rock formations in geomechanical and geological engineering. This study investigates the impact of thermal cycling (0, 50, 100, and 500 cycles between 20–60 ℃) and confining pressure (0, 3, 6, 12, 24, and 48 MPa) on shear fractures induced in dolomite under pure mode II conditions, utilizing the Short Core in Compression (SCC) method on 72 samples. Microstructural evolution and phase transitions were assessed using Scanning Electron Microscopy (SEM) and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) before and after thermal cycling. The evolution of dolomite’s microstructure closely correlated with the results of mechanical tests. The microstructure improved with thermal cycling up to 352 cycles due to the expansion of dolomite grains and a reduction in the void and crack volume. Beyond this threshold, the microstructure deteriorated as void volume and crack expansion increased. Consequently, the fracture toughness and shear modulus of shear fractures induced in SCC specimens increased by 32–111 % and 38–54 %, respectively, under varying confining pressures with increasing cycles up to the 309–379 cycle threshold, after which they decreased. Thermal cycling and lateral pressure have a direct influence on shear fracture morphology. Roughness increased by 16–99 % under varying confining pressures with increasing thermal cycles up to the threshold, as mentioned earlier, which explains the enhanced mechanical properties of these fractures due to increased friction. This study advances our understanding of how thermal cycles and confining pressures affect shear fracture behavior, which is critical for the safety and stability of geological structures exposed to these conditions, such as rock slopes, landslides, and deep geothermal engineering<!--> <!-->projects.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105091"},"PeriodicalIF":5.0,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631101","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":"Investigation and study on the degradation of mode I fracture toughness of coal by soaking effect in abandoned mine water","authors":"Yang Shen ,&nbsp;Baiquan Lin ,&nbsp;Minghua Lin ,&nbsp;Zhiyong Hao ,&nbsp;Ting Liu ,&nbsp;Wei Yang","doi":"10.1016/j.tafmec.2025.105094","DOIUrl":"10.1016/j.tafmec.2025.105094","url":null,"abstract":"<div><div>The stability of fracture zones in abandoned mines under prolonged enclosed conditions has garnered significant attention. On one hand, the unique morphological characteristics of these fracture zones render them particularly susceptible to Mode I fracture propagation. Concurrently, the sustained interaction between mine water/aquifers and the thin coal seams and coal gangue within these fracture zones has been shown to accelerate the degradation process of Mode I fracture toughness. In order to investigate the mechanical degradation effect of abandoned mine water on coal in the fracture zone, this study prepared alkaline mine water with a composition similar to that found in the Panji No. 1 Mine in Huainan. Meanwhile, coal specimens were processed into notched semi-circle bending specimens and subjected to constant temperature–pressure immersion treatments for different durations (7 d, 14 d, 21 d, and 30 d). Subsequently, the treated specimens underwent Mode I fracture testing, during which acoustic emission (AE) technology, digital image correlation (DIC), and crack propagation gauges (CPGs) were incorporated. The main conclusions drawn are as follows: The fracture toughness of the coal specimens decreases as the treatment duration prolongs, from 0.58 MPa·m^1/2 for the raw coal specimen to 0.376 MPa·m^1/2 for the one treated for 30 d. Besides, their fracture length also drop noticeably as the treatment duration lengthens. The stress-time curves reveal a decrease in brittleness and an increase in toughness of the coal specimens. The data of AE signals and CPGs also support this observation. Specifically, the specimens treated for longer durations (21 d and 30 d) exhibit significant reductions in an order of magnitude with respect to both AE signal intensity and fracture propagation speed. Finally, based on the SEM images and the feedback information of surface elements from EDS, the mechanical degradation mechanism of mine water on coal in the temperature–pressure coupling environment in abandoned mines was explored.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105094"},"PeriodicalIF":5.0,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656477","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 path competition and biomimetic toughening strategy in soda-lime glass: Experimental study and phase-field simulation","authors":"Miao Cao ,&nbsp;Ying Qin ,&nbsp;Xiaofei Cao ,&nbsp;Siying Wang ,&nbsp;Jili Liu ,&nbsp;Shuang Xu ,&nbsp;Yongshui Lin ,&nbsp;Weidong Cao ,&nbsp;Chunwang He","doi":"10.1016/j.tafmec.2025.105092","DOIUrl":"10.1016/j.tafmec.2025.105092","url":null,"abstract":"<div><div>Catastrophic fracture in brittle materials has brought persistent challenges in engineering applications. The geometry-induced competition mechanisms as well as the toughening design strategies were limited. In this work, the fracture behavior of soda-lime glass plates was investigated through a combined approach of experimental testing and phase-field numerical simulation. Linear groove defects with varying thickness and inclination angles were introduced to manipulate the crack trajectory and load response. Three representative fracture modes, including Complete deflection, Partial deflection, and Penetration, were observed and the inner competition mechanisms were clarified. Then, a bio-inspired trapezoidal groove structure was proposed and its toughening effect was discussed, which provided a geometrically tunable strategy for crack guidance and toughening. This study revealed the intrinsic mechanisms behind crack path competition in brittle materials. It also provided a practical applicable method for the toughening design of brittle structures.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"139 ","pages":"Article 105092"},"PeriodicalIF":5.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614776","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}