Theoretical and Applied Fracture Mechanics最新文献

{"title":"Fracture process zone of dynamic cracks in brittle materials based on material configurational mechanics","authors":"Chao Wang,&nbsp;Jili Feng","doi":"10.1016/j.tafmec.2025.104922","DOIUrl":"10.1016/j.tafmec.2025.104922","url":null,"abstract":"<div><div>This study investigates the dynamic crack tip fracture process zone (FPZ) by combining dynamic fracture mechanics and material configurational mechanics. The theory of configurational forces is developed within the non-linear dynamic framework, derived from the linear momentum balance equation. Configurational stress for dynamic cracks is estimated, and three J-integrals are calculated. A comprehensive framework is proposed to predict FPZs for both static and dynamic cracks. FPZ predictions are conducted employing Mises yield criterion and maximum normal stress criteria, applied to both Cauchy stress and configurational stress. The impact of crack speed and crack length on the FPZ is systematically analyzed. The predicted plastic zones or process zones align well with experimental photoelastic observations. Notably, the FPZs are observed to increase with increasing crack speed for a moving Griffith crack. Finally, the velocity factors significantly influence the FPZs for propagating cracks. The FPZs typically decrease with increasing crack speed and crack length for propagating cracks.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104922"},"PeriodicalIF":5.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738731","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":"Notch sensitivity on post-cracking behaviour of ultra-high performance fibre-reinforced concrete","authors":"Sneha ,&nbsp;Bineet Kumar ,&nbsp;Sonalisa Ray","doi":"10.1016/j.tafmec.2025.104925","DOIUrl":"10.1016/j.tafmec.2025.104925","url":null,"abstract":"<div><div>The present study focuses on investigating the influence of structural size effect and pre-notch on post-cracking behaviour through extensive numerical and analytical approaches for ultra-high performance fibre-reinforced concrete (UHPFRC). The ductility of UHPFRC is primarily governed by the fibre bridging action that leads to a wider nonlinear inelastic damage zone compared to conventional concrete. This nonlinear inelastic damage zone length is considered as a critical parameter in determining the nominal stress and characterizing the post-cracking tensile behaviour. It significantly governs the size effect behaviour in quasi-brittle materials. Therefore, the proposed study incorporates the effect of nonlinear inelastic damage zone length into the boundary effect model (BEM). The derived formulations consider both the peak load point (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>P</mi><mi>e</mi><mi>a</mi><mi>k</mi></mrow></msub></math></span>) and the second local peak load point (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>M</mi><mi>O</mi><mi>R</mi></mrow></msub></math></span>) in the post-peak region of UHPFRC. A mathematical model for nonlinear inelastic damage zone length has been derived considering three different beam specimens of 75 mm, 150 mm, and 300 mm, having span-to-depth ratio as 2.5. Notch-depth has been varied between 0.1 to 0.27. Within this range, normalized nonlinear inelastic damage zone length at peak load (<span><math><msub><mrow><mi>l</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>/<span><math><mi>D</mi></math></span>) has been observed to vary between 0.2–0.23, 0.25–0.29, and 0.33–0.4 for small, medium, and large specimens, respectively. The calibrated numerical results show a good correlation with experimental and analytical outcomes. Further, based on parameter sensitivity analysis on derived formulation, the specimen size and the length of the nonlinear inelastic damage zone length have been found to be significantly more influential than other parameters.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104925"},"PeriodicalIF":5.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738729","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 mechanisms of granite subjected to varied thermal treatments: Insights into cooling-induced failure characteristics","authors":"Pengju Wang ,&nbsp;Gang Wang ,&nbsp;Changsheng Wang ,&nbsp;Yujing Jiang","doi":"10.1016/j.tafmec.2025.104942","DOIUrl":"10.1016/j.tafmec.2025.104942","url":null,"abstract":"<div><div>Geothermal energy extraction and unconventional oil and gas production inevitably result in cooling shocks for high-temperature rock masses. In this study, the mode I fracture characteristics and failure mechanisms of granite under different temperatures (20–400° C) and cooling methods (air cooling and water cooling) were investigated. Heat-treated semi-circular bend specimens were subjected to three-point bending tests. A formula for calculating the elastic modulus of SCB specimens was proposed. Advanced characterization techniques, including digital image correlation for fracture process zone (FPZ) and crack tip opening displacement (CTOD) measurement, 3D laser scanning for fracture surface morphology analysis, and scanning electron microscopy for fracture surface microstructure examination, were systematically employed. A 3D heterogeneous numerical model was established to study granite temperature and stress changes during heat treatment. The integrated experimental and numerical results reveal the influence of cooling methods on granite fracture mechanisms. As the heating temperature rose, fracture toughness, strain energy, and energy-release rate decreased, whereas the elastic modulus first grew and then decreased. Compared with air cooling, water cooling caused more significant deterioration to the mechanical properties of granite. At the peak load stage, both FPZ length and critical CTOD grew with heating temperature, with a notable increase at 400 °C. However, the FPZ width did not change significantly. Water-cooled granite consistently exhibited longer FPZs and higher critical CTODs than air-cooled granite. With increasing temperature, the surface roughness coefficient increased, but the tortuosity first increased, then decreased. It was found that water cooling resulted in more tortuous fracture paths and rougher fracture surfaces, as well as lower fracture permeability. These findings can provide theoretical and engineering guidance for enhancing deep energy extraction efficiency.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104942"},"PeriodicalIF":5.0,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715488","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 characterization of fracture toughness of X52 pipe steel using CT, SENB, and SENT specimens","authors":"Sylvester Agbo ,&nbsp;Ali Imanpour ,&nbsp;Amr Mohamadien ,&nbsp;Mohammad Kheirkhah Gilde ,&nbsp;Nader Yoosef-Ghodsi ,&nbsp;Samer Adeeb ,&nbsp;Saher Attia","doi":"10.1016/j.tafmec.2025.104941","DOIUrl":"10.1016/j.tafmec.2025.104941","url":null,"abstract":"<div><div>This experimental study investigates the fracture toughness of X52 steel pipe using compact tension (CT), Single Edge Notch Bending (SENB), and Single Edge Notch Tension (SENT) specimen geometries at different initial crack length-to-specimen width ratios. The Digital Image Correlation (DIC) technique is utilized to measure crack opening displacement (i.e., CTOD and CMOD) and crack extension. During loading, the new crack tip is defined as the point of maximum strain perpendicular to the crack plane (i.e., longitudinal strain) within a defined area of interest in the cracked zone (i.e., half area of the crack zone). Load-crack opening displacement records and resistance curves for CT, SENB, and SENT specimens are presented at various crack ratios, providing insights into the influence of constraints and initial crack length-to-specimen width ratios. Critical CMOD, CTOD and J-integral values (i.e., values corresponding to the maximum load) obtained in the tests (CT, SENT and SENB) are presented as a measure of single point fracture toughness for each of the specimens, which could reflect the variation in crack tip constrains associated with varying specimen type and crack lengths. The results of the SENB specimens compared well with a typical similar test conducted on X52 pipe steel. The results shed light on the relationship between fracture toughness obtained from different specimen types for the same steel material and contribute to the development of pipeline material fracture toughness database, showing that dependence on a single fracture toughness test is insufficient. Since each specimen geometry and loading condition represents a different level of constraints. Consequently, fracture toughness predictions from different tests are not directly correlated, reducing their reliability for industrial applications.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104941"},"PeriodicalIF":5.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705475","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":"Application of Taguchi’s optimization techniques for enhancing the fracture characteristics and brittleness of self-compacting alkali-activated concrete","authors":"Imran Kuttagola,&nbsp;M.H. Prashanth","doi":"10.1016/j.tafmec.2025.104931","DOIUrl":"10.1016/j.tafmec.2025.104931","url":null,"abstract":"<div><div>Alkali-activated concrete has emerged as a promising material for energy-efficient construction, offering a technically viable and eco-efficient alternative that aligns with global sustainability goals. This study explores optimizing fracture properties in self-compacting alkali-activated concrete (SAAC) through controlled variations in maximum aggregate size (d_max) and fly ash. A systematic approach incorporating Taguchi’s design of experiments (DOE) and ANOVA analysis was employed to identify optimal mix proportions that enhance fracture performance and ductility. The study employed the Weight-Compensated Work of Fracture Method (WWFM) based on curtailment of the tail of the P–δ curve to determine the size-independent fracture energy (G_F), enhancing the reliability of SAAC in structural applications. Additionally, the Two-Parameter Fracture Model (TPFM) evaluated the critical stress intensity factor (K^s_Ic) and critical crack tip opening displacement (CTOD_c), while the MATLAB-based Box-Counting Dimension Method (BCDM) assessed the fractal dimension (D). The findings revealed a higher fracture performance with 0 % fly ash and 16 mm d_max (G_F of 206.3 N/m and K^s_Ic of 1.91 MPa√m), suitable for structural applications requiring maximum fracture energy and toughness. The study further tailored a higher ductility mix with 50 % fly ash and 16 mm d_max (CTOD_c of 0.032 mm and D of 1.144) offering a balanced solution for non-structural applications, providing sufficient strength with enhanced ductility. The closed-form predictive design (CPD) model enables the prediction of f_t and K_Ic under a specified maximum fracture load, offering engineers a practical tool to optimize SAAC formulations by adjusting aggregate sizes and binder proportions for specific project needs. Regression models aligned strongly with experimental and existing literature results, affirming the reliability of predictive performance for future SAAC mix designs.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104931"},"PeriodicalIF":5.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696791","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":"Study on the interaction mechanisms between the fissure arrays and circular tunnels by physical experiment and meshless numerical method","authors":"Xueying Hu ,&nbsp;Shibing Huang ,&nbsp;Shuyang Yu ,&nbsp;Yifei Li ,&nbsp;Xiangyu Wang","doi":"10.1016/j.tafmec.2025.104935","DOIUrl":"10.1016/j.tafmec.2025.104935","url":null,"abstract":"<div><div>Fissure arrays, which commonly develop in surrounding rock masses, exert a significant adverse influence on tunnel stability. However, current research on the interactions between fissure arrays and tunnels are limited. In this study, specimens with fissure arrays and central holes are prepared using sand-three-dimensional printing (S-3DP) technology, with variations in fissure angles, lengths, and numbers. The crack propagation experiments are subsequently carried out, in which the propagation of fissures is monitored and recorded by employing Digital Image Correlation (DIC) methodology. Then, the developed smooth particle dynamics method is used to simulate and analyze crack evolution processes as a comparison. The results demonstrate that an increase in fissure inclination angle leads to an enhancement in specimen peak strength, whereas increases in fissure length and number result in a reduction in peak strength. Four basic crack types, namely tensile cracks (T-Ⅰ and T-ⅠⅠ), shear cracks (S), and tensile-shear mixed cracks (TS), are quantitatively identified using DIC technology. In addition, the rupture modes can be categorized into four distinct types: horizontal splitting damage mode, stepped damage mode, “Y”-shaped damage mode, and tensile-shear mixed damage mode. Distributions of tensile and compressive stress concentration areas should be responsible for the crack initiation and the final failure modes, because these stress concentration areas not only trigger the initial formation of cracks, but also guide the crack propagation paths. This study provides novel insights into the fracture mechanisms of tunnels containing fissure arrays, while also offering valuable references for the safe construction and long-term operation of tunnel engineering projects.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104935"},"PeriodicalIF":5.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685383","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":"When is a notch a Crack? Analysis of an early paper by Rod Smith and Keith Miller","authors":"David Taylor","doi":"10.1016/j.tafmec.2025.104939","DOIUrl":"10.1016/j.tafmec.2025.104939","url":null,"abstract":"<div><div>In 1978 Rod Smith published a paper, co-authored by Keith Miller, on the subject of notch fatigue limits. Of the many valuable contributions which Rod made to our field, this paper stands out for me. I believe it to be an excellent example of good science, bringing clarity to a field which was (and still is) characterized by complexity. In what follows I introduce the paper and in particular a type of plot used in it, which I propose to name the Smith-Miller diagram. This diagram is of great practical use in engineering design for the assessment of stress concentration features and also has applications in forensic failure analysis and in undergraduate teaching, areas in which Rod Smith also excelled.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104939"},"PeriodicalIF":5.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using crack face displacement to measure stress intensity: A practical approach","authors":"Anis Allahdiniyan,&nbsp;David Taylor","doi":"10.1016/j.tafmec.2025.104940","DOIUrl":"10.1016/j.tafmec.2025.104940","url":null,"abstract":"<div><div>This study presents a novel method for estimating the stress intensity factor (K) using direct measurements of crack face displacements. Starting from Westergaard’s analytical solutions, modifications were derived from adapting these equations for finite-width bodies in five different geometries, including centre crack plates, edge crack plates (with both single and double cracks), plates containing angled cracks, and cracks in three-point bend specimens. Finite Element Analysis (FEA) was used to determine the profile of crack face displacement at different points along each crack. It was found that for centre-cracked plates, Westergaard’s equation worked well with only slight correction needed, whilst for edge-cracked geometries, a different equation was needed to describe the displacement profile. Unlike conventional methods that require applied load or local stress–strain data, this approach provides a simple and practical means of estimating K using optical measurements of crack face displacement. The proposed equations correctly predicted K with errors less than 10% for all geometries considered. To demonstrate the practical use of this method, an experimental study was conducted to estimate the fracture toughness (K_IC) of leaf specimens using crack face displacement measurements. The results were within 3% of those obtained from conventional laboratory tests, confirming the feasibility of this approach for real-world applications. Other potential applications to different materials and structures were also proposed. These findings establish crack face displacement as a reliable parameter for fracture analysis, offering potential applications in material testing, non-destructive evaluation, and structural health monitoring.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104940"},"PeriodicalIF":5.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on fracture characteristics of 3D-ILC brittle solids under high-temperature loading in three-point bending","authors":"Haoran Zhang ,&nbsp;Shu Zhu ,&nbsp;Zhende Zhu ,&nbsp;Junyu Wu","doi":"10.1016/j.tafmec.2025.104938","DOIUrl":"10.1016/j.tafmec.2025.104938","url":null,"abstract":"<div><div>This study predicts the mechanical behavior and crack propagation of rock-like materials under high-temperature conditions in deep engineering applications through experimental and numerical simulations. The 3D-ILC method was utilized to induce three-dimensional fissures in a semi-circular disk specimen. The three-point bending test following high-temperature cooling was conducted to analyze the failure mode and fracture morphology. By integrating the maximum tensile stress criterion, M−integral method, and finite element analysis, a thermomechanical simulation of three-dimensional crack propagation is conducted. This reveals the relationship between the stress intensity factor at the crack tip and the relative circumference of the crack front, enabling a detailed visualization of the crack propagation path. The results show that the horizontal single crack extends in a “U”-shaped pattern with increasing temperature, while dynamic fracture occurs along the crack center during the three-point bending test. At high temperatures, crack propagation in the specimens is primarily governed by Mode I, whereas in the three-point bending tests, crack propagation transitions through Modes I, II, and III. This study provides a robust framework for analyzing the mechanical behavior of rock-like materials under thermal and mechanical loading in deep engineering environments.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104938"},"PeriodicalIF":5.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685385","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":"Quantification of the stress field associated with mixed-mode I/II crack initiation considering the pre-existing weak interlayers: A photoelastic experimental study using 3D printed transparent models","authors":"Wang Guo ,&nbsp;Yang Ju ,&nbsp;Chao Chen ,&nbsp;Yihao Zhang ,&nbsp;Guoming Fu","doi":"10.1016/j.tafmec.2025.104926","DOIUrl":"10.1016/j.tafmec.2025.104926","url":null,"abstract":"<div><div>Accurate identifying and describing the full-field stress distribution and fracture parameters at the crack tip in rock structures with primary fractures and weak interlayers lay the groundwork for predicting the structural failure behavior of rock masses. This study utilizes 3D printing to create flat-plate models with weak interlayers and open-inclined cracks. The ten-step phase-shift method is applied to obtain the full-field stress of the model. The stress intensity factors at the crack tip are determined using crack multiparameter stress field equations and the nonlinear over-determined least squares method, with an analysis of the method’s reliability. The study explores the effects of mechanical properties, distribution, and length of weak interlayers on the full-field stress difference and stress intensity factor at the crack tip under uniaxial compression. By conducting experiments on low-temperature uniaxial compression, we conducted an analysis of crack propagation characteristics and the influence exerted by weak interlayers. The results indicate the robust reliability of the combination of the ten-step phase-shift method, the multiparametric equation for the crack tip, and the nonlinear over-determined least squares method in evaluating stress intensity factors at the crack tip. The weak interlayer has the potential to shield the principal stress difference and stress intensity factors <em>K</em>_I and <em>K</em>_II at crack tips, with this shielding effect being influenced by the mechanical properties, distribution, and length of the weak interlayer. The <em>T</em> stress at the crack tip is influenced by the mechanical properties, distribution, and length of the weak interlayer. At −50 ℃, crack propagation undergoes a slow growth stage and a rapid growth stage. The presence of weak interlayers hinders the propagation of cracks and may affect the initiation direction of cracks.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104926"},"PeriodicalIF":5.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685308","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}