Theoretical and Applied Fracture Mechanics最新文献

{"title":"A load-adaptive multi-level feature fusion method for predicting metal fatigue crack length based on lamb wave and strain signals","authors":"Qiang Gao,&nbsp;Hua Li,&nbsp;Xiaotian Wang,&nbsp;Junzhou Huo,&nbsp;Youfu Wang","doi":"10.1016/j.tafmec.2025.105268","DOIUrl":"10.1016/j.tafmec.2025.105268","url":null,"abstract":"<div><div>Accurate identification of metal fatigue cracks can promptly warn about the structural service condition. Based on piezoelectric lamb wave and strain signals, this paper proposes a multi-level feature fusion method for heterogeneous signals, combined with the self-attention mechanism, to accurately predict crack length under multiple load conditions. Firstly, the long-sequence piezoelectric lamb wave data is segmented, and the segmented piezoelectric lamb wave data features are extracted through long short term memory (LSTM). The output results of multiple LSTMs are fused through a one-dimensional convolutional neural network (1DCNN). At the same time, the strain signals under various load conditions are pre-processed for features, and then the features of the strain signals are fused through the 1DCNN module. Through the self-attention mechanism for adaptive feature fusion of the two sensor signals, the weights of piezoelectric lamb wave features and strain signal features can be adaptively optimized and adjusted. Combined with the strain feature preprocessing, the model can better adapt to different load conditions. Finally, the experiment on the compression and tensile (CT) specimens is conducted to verify the fusion model and the prediction results of the single sensor. Multiple evaluation metrics are used to compare and analyze the prediction results of the fusion model and the single sensor, verifying the effectiveness of the proposed fusion method for crack length prediction.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105268"},"PeriodicalIF":5.6,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268367","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 non-uniform loading on brittle fractures and 3D crack growth under uniaxial compression","authors":"Hongyu Wang ,&nbsp;Liangkai Li ,&nbsp;Arcady Dyskin ,&nbsp;Elena Pasternak ,&nbsp;Guowei Ma","doi":"10.1016/j.tafmec.2025.105273","DOIUrl":"10.1016/j.tafmec.2025.105273","url":null,"abstract":"<div><div>The uniaxial compression test is a fundamental method for simulating the stress conditions that experienced by rock masses in the walls or pillars of underground openings. While such tests are typically assumed to be conducted under uniform loading, where the loading surfaces (top and bottom specimen ends) are the principal planes, non­uniform loading is often unavoidable in real testing. The loading non-uniformity may arise from specimen preparation or experimental set­up. In this study, a transparent and inherently brittle modelling material, rosin, was used to investigate the effects of non­uniform loading on brittle fractures and 3D crack growth under uniaxial compression. A key criterion proposed for sufficiently uniform loading is that wing cracks initiate from a centrally located 3D initial crack without the development of premature fractures prior to final failure. Results from both physical experiments and finite element modelling show that even minor unevenness at specimen ends can induce inclined tensile fractures near the ends, while the use of soft lubricant produces tensile stresses distributed across the entire loading surfaces, leading to splitting fractures sub-parallel to the loading direction. Both conditions could suppress 3D crack growth. Eccentric loading results in edge spalling and asymmetric wing crack growth from the upper and lower parts of the initial crack contour. This study provides new insights into the influence of loading conditions on brittle fracture mechanisms and offers practical guidance for reliable 3D crack growth experiments under compressive loading.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105273"},"PeriodicalIF":5.6,"publicationDate":"2025-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267852","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":"Effects of cyclic stress lower limit on the mechanical behavior and energy instability precursor characteristics of rock with hole-shaped flaw","authors":"Peilei Zhang ,&nbsp;Song Luo ,&nbsp;Xuefeng Si ,&nbsp;Congxiang Yuan ,&nbsp;Meng Wang","doi":"10.1016/j.tafmec.2025.105270","DOIUrl":"10.1016/j.tafmec.2025.105270","url":null,"abstract":"<div><div>Cyclic compression tests are conducted to investigate the effects of cyclic stress lower limits on the mechanical behavior and energy response of rocks with hole-shaped flaw. The results show that increasing the stress lower limit accelerates internal damage accumulation and promotes an apparent hardening. This is manifested in a higher loading and unloading moduli, reduced peak strength and plastic deformation, and a transition toward more brittle and catastrophic failure behavior. When the stress lower limit approaches zero, the rock exhibits softening behavior and undergoes a relatively mild failure process, with failure primarily localized along a single dominant shear band through the flaw. From the perspective of energy, the gradual increase of stress lower limit has produced more instability characteristics. The energy storage (or release) rate initial increases and then decreases, exhibiting a peak prior to failure. While the energy dissipation rate rises monotonically. In contrast, under a constant stress lower limit, the energy rate evolves steadily without significant mutation. Finally, an energy-based instability precursor indicator is established based on the energy rate difference (ERD) and its effectiveness is also evaluated through correlation with acoustic emission (AE) characteristics during cyclic loading. ERD exhibits a more pronounced and sensitive instability precursor signature compared to conventional indicators, where both the peak value and the rate of post-peak decline provide quantitative insight into the severity of impending failure. This makes ERD a robust and reliable tool for predicting the instability of flawed rock masses under cyclic loading.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105270"},"PeriodicalIF":5.6,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268351","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":"Freeze-thaw induced structural deterioration of fractured rock: A coupled NMR–CT study on pore network evolution","authors":"Yongxin Che,&nbsp;Yongjun Song,&nbsp;Huimin Yang,&nbsp;Hao Tan,&nbsp;Leitao Zhang","doi":"10.1016/j.tafmec.2025.105274","DOIUrl":"10.1016/j.tafmec.2025.105274","url":null,"abstract":"<div><div>Freeze-thaw cycling is one of the main drivers of rock-mass deterioration in cold regions, markedly altering pore structure and permeability. In this study, intact sandstone and pre-fabricated fractured sandstone were examined with a combined nuclear magnetic resonance (NMR) and X-ray computed tomography (CT) program to track multiscale pore-structure evolution. The results show that freeze-thaw action shifts the pore-size toward larger pores: (1) In fractured and intact specimens, the fraction of micropores fell by 22 %, while the fraction of macropores (or microcracks) rose by 114 % and 60 %, respectively; mesopores changed little. The meso-to-macropore fractal dimension measured by NMR decreased in tandem. (2) CT reconstructions revealed a pronounced rise in microcrack volume fraction (intact: from 82.7 % to 88.8 %; fractured: from 79.7 % to 90.1 %), along with total-porosity increases of 21 % and 30 %. The proportion of connected pores climbed from 51 % to 77 % in fractured sandstone and from 56 % to 71 % in intact sandstone. (3) Pre-fabricated fractures, as structural weak planes, strongly magnify freeze-induced pore enlargement, reorganization, and connectivity, driving the pore network from a disordered toward a more ordered, interconnected architecture. These findings furnish multiscale experimental evidence and mechanistic insight for assessing the stability of cold-region rock masses and designing protective measures.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105274"},"PeriodicalIF":5.6,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268350","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":"Extension and validation of the Finite Fracture Mechanics Coupled Criterion to V-notched specimens under small scale yielding conditions","authors":"Zohar Yosibash ,&nbsp;Pietro Cornetti","doi":"10.1016/j.tafmec.2025.105237","DOIUrl":"10.1016/j.tafmec.2025.105237","url":null,"abstract":"<div><div>We extend the Finite Fracture Mechanics Coupled Criterion (FFMCC) to V-notched specimens made of steels, where small-scale yielding occurs at the notch tip. By introducing a circular “plastic area” with a power-law degradation of the Young’s modulus, an asymptotic analysis is developed to compute the dissipated energy and failure load analytically. The coupled stress and energy release rate criteria are reformulated using matched asymptotic expansions, and tabulated functions enable straightforward failure prediction. The extended FFMCC is an easy method that requires simplified FE solutions, validated herein by four-point bending experiments (4PB) on AISI 4340 and H13 steel specimens with different V-notch angles and tempering treatments. The predicted failure loads and plastic area show very good agreement with experimental results, demonstrating the robustness and practicality of the proposed analytic extension for steels in the presence of small-scale yielding.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105237"},"PeriodicalIF":5.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268355","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 investigation on crack propagation and fracture process zone evolution in flame-treated granite","authors":"Yunhong Guo ,&nbsp;Qifeng Guo ,&nbsp;Libo Liu ,&nbsp;Wenhui Tan ,&nbsp;Siwei Wu ,&nbsp;Xiong Yin ,&nbsp;Jiliang Pan","doi":"10.1016/j.tafmec.2025.105267","DOIUrl":"10.1016/j.tafmec.2025.105267","url":null,"abstract":"<div><div>To investigate the mechanisms of crack propagation in thermally treated granite, rapid thermal disturbance was simulated using flame heating at 25–600 °C, followed by three-point bending tests. Crack propagation paths and crack tip responses were dynamically analyzed using digital image correlation (DIC). The results demonstrate that thermal treatment markedly weakens the structural integrity of granite: Fracture toughness decreases by 64.5 %(from 49.17 MPa·mm^0.5 To 17.46 MPa·mm^0.5), crack tip opening displacement increases to 33.5 μm, and the fracture process zone (FPZ) extends to 17.33 mm. Crack propagation mode evolves from brittle failure at ambient temperature to stable and asymmetric growth at elevated temperatures. Scanning electron microscopy (SEM) reveals that microcracks initiate along grain boundaries and progressively extend into grains, forming a connected damage network. With increasing temperature, stress concentrations induced by heterogeneous mineral thermal expansion accumulate, and near 573 °C, the α–β phase transition of quartz causes abrupt unit cell volume change and local stress redistribution, serving as a critical driver of high-temperature structural degradation</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105267"},"PeriodicalIF":5.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221506","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":"Flexural and fracture properties of fiber-reinforced alkali activated composites derived by waste tailings coal gangue power generation slag","authors":"Jun Li ,&nbsp;Shuai Zhang ,&nbsp;Hesong Jin ,&nbsp;Minghao Chen ,&nbsp;Xianzhang Liu ,&nbsp;Xinlong Zhu ,&nbsp;Xueyu Wei","doi":"10.1016/j.tafmec.2025.105260","DOIUrl":"10.1016/j.tafmec.2025.105260","url":null,"abstract":"<div><div>Industrial waste-derived alkali activated composites demonstrated lower carbon footprint, and higher reutilization potential of solid by-products, such as various tailings, compared with conventional cementitious system, but its brittleness and bending fracture remain still the challenges required to be tailored further. Herein, granulated blast furnace slag (GGBFS) and coal gangue power generation slag (CPS) were mixed with glass fiber (GF) and polypropylene fiber (PPF) at dosages of 0.3 %, 0.5 %, and 0.7 % to develop low-carbon fiber-reinforced geopolymer composites. The effects of glass and polypropylene fibers on the mechanical properties, flexural and fracture properties of fiber-reinforced geopolymer composites were studied. Compressive strength, fracture behavior, and crack evolution were examined via uniaxial compression, three-point bending test, and digital image correlation (DIC). The fracture characteristics were quantitatively evaluated via the double-<em>K</em> model. Results showed that glass and polypropylene fibers significantly improved fracture resistance of fiber-reinforced geopolymer composites. DIC analysis revealed that polypropylene fiber/glass fiber delayed crack initiation and promoted complex crack networks via bridging effects. The GF-0.5 group showed a 40 % delay in crack initiation and a 25 % reduction in maximum shear strain, and its compressive and flexural strengths increased by 19 % and 79 %, respectively, compared to control group. The hybrid fiber group (MF-0.5) showed remarkable fracture energy absorption of 279.87 N/m, representing a 689 % enhancement compared to control group, clearly showing the synergistic reinforcement mechanism of fiber hybridization. SEM and FT-IR results confirmed that while fiber can adhere more C-(A)-S-H gels, it strengthened the bond between gel and fibers, confirming the hybrid fiber mechanisms—bridging, fracture, and pull-out—substantially improved ductility, toughness, and crack resistance. More importantly, fiber-reinforced geopolymer composites offer a 35 % reduction in carbon emissions and lower costs compared to traditional cement-based materials. Overall, this study shows that optimizing geopolymer formulations with industrial waste significantly improves performance, supports solid waste valorization, and offers a sustainable pathway for green building materials.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105260"},"PeriodicalIF":5.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268354","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":"Calculation of dynamic stress intensity factors for cracked bridges under moving train load","authors":"Huile Li ,&nbsp;Chunxi Li ,&nbsp;Yusen Li","doi":"10.1016/j.tafmec.2025.105253","DOIUrl":"10.1016/j.tafmec.2025.105253","url":null,"abstract":"<div><div>Accurate determination of the stress intensity factors for cracked bridges is crucial for their fracture and fatigue analysis. This paper proposes a generalized approach for the dynamic stress intensity factor calculation of cracked bridges subjected to moving train load. Dynamic equation of the cracked bridge is established by the extended finite element method, based on which 3D train-bridge coupled system model is formulated to characterize dynamic interactions between the train and cracked bridge and to yield near-tip displacement and stress fields. The interaction integrals of dynamic stress intensity factors for 3D railway bridge cracks are analytically deduced and numerically evaluated in conjunction with the extended finite element method for the first time. Three benchmark examples are subsequently used to verify the effectiveness of the developed computational procedure. Additionally, the proposed approach is illustrated on a cracked prestressed-concrete girder bridge in heavy-haul railway and the influence of key parameters on dynamic stress intensity factors is investigated. In the present work, two categories of dynamic effects in the determination of dynamic stress intensity factors are identified and quantified, which refer to coupled vibrations between the train and cracked bridge and inertial effects in the near-tip region, respectively. Capable of considering the above-mentioned dynamic effects, track irregularities, and prestress levels, among others, the proposed approach can be employed to accurately calculate dynamic stress intensity factors for 3D cracks in a variety of railway bridges under moving train load.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105253"},"PeriodicalIF":5.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268356","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":"Acoustic emission characterization of mode I fracture in asphalt mixtures at intermediate temperatures","authors":"Weimin Song ,&nbsp;Wenlong Yan ,&nbsp;Hao Wu ,&nbsp;Yuxuan Sun ,&nbsp;Xiaobao Chen ,&nbsp;Zhiqiang Cheng ,&nbsp;De Zhang","doi":"10.1016/j.tafmec.2025.105271","DOIUrl":"10.1016/j.tafmec.2025.105271","url":null,"abstract":"<div><div>This study investigated the Mode I fracture behavior of AC10 and AC16 asphalt mixtures at intermediate temperatures (10 °C and 25 °C) utilizing semi-circular bending (SCB) tests coupled with acoustic emission (AE) monitoring. Analysis of key parameters—fracture energy, equivalent stress intensity factor (<em>K</em>_<em>IC</em>*), and AE-derived cumulative energy/count—revealed that AC10 exhibited significantly higher <em>K</em>_<em>IC</em>* and fracture energy than AC16, indicating superior resistance to both pre- and post-region cracking. Concomitantly, cumulative AE energy and count delineated three distinct damage stages: Stage I involves micro/meso-crack development and void closure; Stage II features alternating plateaus and sharp growth points with rapid parameter increases, reflecting accelerated damage; Stage III marks rapid failure with inapparent growth of the cumulative count and energy. Load ratio analysis further demonstrated AC10's higher initiation load-to-peak load ratio and lower failure load-to-peak load ratio versus AC16, signifying slower damage propagation and better fracture resistance. Crack classification via a Gaussian mixture model (GMM) applied to RA-AF data confirmed that tensile cracks are dominant, with AC10 exhibiting a greater proportion of tensile cracks than AC16 at equivalent temperatures. Collectively, these results underscore the significant influence of mixture composition on fracture mechanics and AE response, providing critical insights for optimizing asphalt design to enhance intermediate-temperature cracking resistance.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105271"},"PeriodicalIF":5.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221505","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":"Dynamic crack characteristic and failure mechanism of fractured granite under the influence of fissure angle and impact velocity","authors":"Tong Zhang ,&nbsp;Yongnan Li ,&nbsp;Bin Liu ,&nbsp;Huajian Zhu ,&nbsp;Mengqi Jin","doi":"10.1016/j.tafmec.2025.105265","DOIUrl":"10.1016/j.tafmec.2025.105265","url":null,"abstract":"<div><div>The energy-release dependent rock burst is crucial to the tunnel engineering for fractured granite rock. To study the influence of fissure angle and impact velocity on the mechanical properties and failure behavior of fractured granite, dynamic tensile tests were conducted by the Split Hopkinson Pressure Bar system, and dynamic fracture morphology and damage condition were monitored through the digital image correlation (DIC) method. The mechanical response and energy evolution of fractured granite under the varying impact velocities were analyzed, and the crack propagation mechanism was revealed by the Particle Flow Code method. The results show that the failure mode of fractured granite transits from tensile damage to tensile-shear mixed damage with the increasing impact velocity, and tensile damage, tensile-shear mixed damage, and tensile damage were successively observed with the increase of fissure angle. In addition, the failure morphology was gradually dominated by increasing impact velocity with the weakened influence of fissure angle, and the crack initiation gradually shifted from the fissure tip into the center of the fissure. Simultaneously, the dissipated energy density and energy dissipation rate exhibit a non-monotonic “increase-decrease-increase” evolution trend with increasing fissure angle, and present a decrease trend from 32.70 % to 11.64 % with the increasing impact velocity. The highest and lowest dissipation rates were presented at 45° and 0° fissure angle for 0.30 MPa loading stress. The minimal tensile stress occurred at 30°, and the highest shear stress was presented at 45° for the stress intensity factor. The finding provides insight into the theoretical analysis and numerical simulation of fractured rock burst in an extreme environment.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"141 ","pages":"Article 105265"},"PeriodicalIF":5.6,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220874","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}