Engineering Fracture Mechanics最新文献

{"title":"Influences of initial damage on the saturated granite failure characteristics under true triaxial stress with a free face: Insights into the rockburst prevention and control","authors":"Bing-Lei Li ,&nbsp;Jia-Yao Jiang ,&nbsp;Jian-Zhi Zhang ,&nbsp;Lu Zheng ,&nbsp;Yi Long","doi":"10.1016/j.engfracmech.2025.111263","DOIUrl":"10.1016/j.engfracmech.2025.111263","url":null,"abstract":"<div><div>The moisture content and damage conditions significantly influenced the mechanical properties of hard rock, which are closely associated with rockburst tendency. However, there was limited prior knowledge of this issue due to the scarcity of physical experiments. In this study, a true triaxial experiment with a free face was conducted on granite specimens to investigate the influence of the initial damage and moisture content on rockburst control, utilizing AE monitoring, rock NMR imaging, and photography techniques. Experimental results showed that with the increase of the initial damage factor <em>k</em> and moisture content <em>ω</em>, the rock strength and AE activity decreased. The static crack extension concentrated around the initial damage zone, and the dynamic ejection decreased, leading to an increase in the fracture surface fracture index. When<!--> <em>k</em> and <em>ω</em> <!-->increased to a certain extent, the tensile mechanism was significantly reduced, and then the rockburst was efficiently prevented. The failure mechanism lay the initial damage zone weakened the strength of the granite matrix, inducing the FPZ nucleation and crack extension. Furthermore, the rockburst envelope of the granite was altered, with the reduced envelope area indicating a decrease in stored energy, resulting in the granite having insufficient energy to trigger a rockburst upon failure. In addition, due to the “water wedge” effect, the moisture content further enhanced the weakening effect of the initial damage factor on rockburst tendency.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111263"},"PeriodicalIF":4.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148030","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 micromechanics-based anisotropic friction–damage model for quasi-brittle rocks in monotonic compression considering dominant cracking process","authors":"Lun-Yang Zhao ,&nbsp;Ling-Hui Liu ,&nbsp;Lu Ren ,&nbsp;Qi-Zhi Zhu ,&nbsp;Jian-Fu Shao","doi":"10.1016/j.engfracmech.2025.111180","DOIUrl":"10.1016/j.engfracmech.2025.111180","url":null,"abstract":"<div><div>In this work, a new micromechanics-based model is developed for describing the anisotropic mechanical behavior of quasi-brittle rocks in monotonic compression. The material is conceptualized as an isotropic elastic matrix embedded with randomly distributed initial microcracks. Based on experimental evidences and as an innovative approach, the stress-induced coupled anisotropic damage and plastic distortion are assumed related to the propagation and sliding of the dominant microcracks in the most unstable orientations under given loading state, instead of related to microcracks in all orientations as done in the previous studies. In this frame, by combining the thermodynamics framework and linear homogenization scheme, an energy-release-rate based damage law is developed for describing the induced anisotropic evolution of dominant microcracks. The plastic distortion is related to frictional sliding along the rough dominant microcracks and described by a damage-dependent friction law. The direction of dominant microcracks is identified by using Mohr maximization postulate. Further, the macroscopic failure strength is predicted from the coupled friction–damage analysis. The process for calibration of the microscopic parameters from macroscopic strength is developed. As another novelty of the present work, an enhanced semi-implicit return mapping (ESRM) algorithm is proposed to more efficiently dealing with two dissipation processes of plastic deformation and damage evolution. The effectiveness of the proposed model and the robustness of the ESRM algorithm are finally evaluated.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111180"},"PeriodicalIF":4.7,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144115591","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":"Analysis of the relationships between mechanical conditions and acoustic emission signal characteristics from prestressing steel wire breaks","authors":"Max Fiedler,&nbsp;Ronghua Xu,&nbsp;Steffen Marx","doi":"10.1016/j.engfracmech.2025.111210","DOIUrl":"10.1016/j.engfracmech.2025.111210","url":null,"abstract":"<div><div>Acoustic emission (AE) has emerged as a reliable technique for detecting wire breaks from stress corrosion cracking (SCC) in prestressed concrete structures. The relationship between mechanical boundary conditions at the fracture location and the characteristics of the AE signal is of significant interest for monitoring applications because the released energy influences the sensor layout design. However, this relationship has not been thoroughly examined to date. This study addressed this gap by conducting controlled tensile tests on individual wire samples. A comprehensive dataset encompassing various wire lengths and stress levels was generated. The wire samples were obtained from a demolished prestressed concrete bridge susceptible to stress corrosion cracking. Following fracture mechanics theories, the findings reveal that higher applied stresses correlate with higher peak-amplitudes and energy of the AE signals. Additionally, the wire length affected AE signal characteristics, with shorter samples exhibiting more significant signal scattering. The influence in intensity was less pronounced, but longer samples showed increased frequency content. No direct superimposition of stress and wire length effects was observed, as these factors appear to act independently, likely due to different impacts on either the wave pressure or the frequency content. These findings form a baseline for transferring results from artificially induced wire breaks, e.g. under a laboratory environment or during material sampling at bridges, to spontaneous events caused by SCC in monitoring applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111210"},"PeriodicalIF":4.7,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098824","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":"Corrigendum to “Transition time threshold for Double Cantilever Beam specimens under high loading rates” [Eng. Frac. Mech. 249 (2021) 107754]","authors":"S.A. Medina,&nbsp;E.V. González,&nbsp;N. Blanco","doi":"10.1016/j.engfracmech.2025.111219","DOIUrl":"10.1016/j.engfracmech.2025.111219","url":null,"abstract":"","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"323 ","pages":"Article 111219"},"PeriodicalIF":4.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167804","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":"Characterizing the fracture evolution of sandstone by using Mel-frequency cepstral coefficients of acoustic emission","authors":"Fei Yang ,&nbsp;Zhenlei Li ,&nbsp;Shimin Liu ,&nbsp;Xueqiu He ,&nbsp;Dazhao Song ,&nbsp;Na Li ,&nbsp;Honglei Wang ,&nbsp;Aleksei Sobolev","doi":"10.1016/j.engfracmech.2025.111254","DOIUrl":"10.1016/j.engfracmech.2025.111254","url":null,"abstract":"<div><div>Study of damage and fracture of rocks is important for monitoring and forecasting of dynamic hazards in mines, tunnels, rock bodies and other engineering. Under the conditions of uniaxial loading, stepwise loading, cyclic loading, sandstone loading and destruction experiments were conducted and full waveform monitoring of acoustic emission (AE) was synchronized. The Mel-frequency cepstral coefficient (MFCC) of AE signals was extracted from the whole sandstone loading process. Then, the MFCC was combined with the video camera of sandstone fracture process and the strain analysis using digital image correlation (DIC), to characterize the response of MFCCs for the sandstone fracture process, and to examine the relationship between the MFCC of AE and the fracture of sandstone. In addition, the advantages and underlying mechanism of this coefficient for characterizing sandstone fracture were discussed. The results show that, for different loading conditions, there are fluctuations of MFCC-1 in the loading stage, among which, the fluctuations of MFCC-1 are small and random in the compression and elastic stages, and the fluctuation amplitude significantly increases and shows significant periodicity in the unstable deformation and post-peak failure stages, whereas the MFCC-1 is approximately constant with almost no fluctuations in the load-holding and unloading phases. A large number of new fractures in the sandstone start from the unstable deformation stage at the late loading period and continue throughout the whole failure process, and the new fractures are generated in a regular, intermittent and violent manner, resulting in AEs in the form of intermittent high-amplitude waveform clusters; in the compaction and elastic stage, the new fractures are fewer in number, and the closure friction of the original fracture is dominant, resulting in the random generation of AE in the form of a single waveform. Unlike conventional parameters such as AE energy and ringing counts, which mainly characterise individual waveforms, the MFCC mainly characterises the overall AE waveforms over a period of time, and is less affected by individual waveforms. This can explain why the MFCC exhibits different responses at different loading stages of the sandstone and has an advantage in characterizing sandstone rupture. Among them, the fluctuation of MFCC-1 is reflection of the fracture and damage process of sandstone, the significant periodic fluctuation of MFCC-1 is a precursor of sandstone destabilization and damage, and the significant sudden rise during the fluctuation of MFCC-1 foretells the emergence of macroscopic cracks in sandstone. The MFCC can be used as an important parameter in the analysis of AE. The research results provide a new means of analysis of the evolution of fractures in coal rock.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111254"},"PeriodicalIF":4.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106840","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":"Numerical simulation of progressive interfacial debonding in three-phase piezoelectric composites using Voronoi cell finite element method","authors":"Zhiyi Wang ,&nbsp;Rui Zhang ,&nbsp;Bing Pan","doi":"10.1016/j.engfracmech.2025.111257","DOIUrl":"10.1016/j.engfracmech.2025.111257","url":null,"abstract":"<div><div>To address the performance degradation caused by interface debonding in three-phase piezoelectric composites under electromechanical loading conditions, this study proposes a novel electromechanical coupling numerical model based on the Voronoi Cell Finite Element Method (VCFEM). A three-phase stochastic Voronoi microstructure generation algorithm is developed to establish heterogeneous geometric representations comprising piezoelectric particles, polymer matrix, and interphase layers. Building upon the derived minimum complementary energy principle, a novel variational functional is formulated through the electromechanical coupling field governing equations. This formulation introduces: (1) independent stress and electric displacement fields within element domains, (2) autonomous displacement and electric potential fields along element boundaries, thereby establishing a unified functional that intrinsically couples these four field variables. The Lagrange multiplier method is employed to enforce displacement-electric potential constraints at interfaces. A modified complementary energy functional is proposed to ensure generalized traction continuity across both matrix-interphase and inclusion-interphase interfaces, while maintaining zero generalized traction on crack surfaces. This approach achieves precise simulation of progressive interfacial debonding under electromechanical interactions. Numerical examples simulating interfacial debonding in three-phase piezoelectric composites demonstrate the validity and robustness of the proposed model through comparative analyses with conventional Finite Element Method (FEM). This research provides an efficient simulation tool for interface optimization design of piezoelectric composites under electromechanical loading conditions, which can be extended to reliability assessment of other multiphase smart material systems through generalization of microstructure generation rules and failure criteria.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111257"},"PeriodicalIF":4.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134335","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":"True-triaxial strength and failure characteristics of sandstone within brittle-ductile domain: An experimental and theoretical study","authors":"Jiacun Liu ,&nbsp;Xing Li ,&nbsp;Junjie Xiao ,&nbsp;Ying Xu ,&nbsp;Bangbiao Wu","doi":"10.1016/j.engfracmech.2025.111255","DOIUrl":"10.1016/j.engfracmech.2025.111255","url":null,"abstract":"<div><div>As the depth of underground construction increases, rocks progressively transition from brittle to ductile behavior. Therefore, understanding the true-triaxial strength and failure characteristics of rocks within brittle-ductile domain is crucial for underground engineering applications. A series of true triaxial tests, following a constant Lode angle loading path, were conducted on high-porosity green sandstone. To accurately characterize the variation in true-triaxial strength within the brittle-ductile domain, this study introduces a generalized three-dimensional strength criterion. This criterion incorporates a two-parameter deviatoric function and a segmented meridian function. The strength data of green sandstone and Bentheim sandstone are symmetrically distributed around the three-dimensional failure envelopes, validating the applicability and accuracy of the proposed criterion. The macroscopic and microscopic failure characteristics of green sandstone are analyzed. The failure modes of green sandstone can be broadly classified into three types. Type I is characterized by multiple interacting shear bands, Type II by several discrete shear bands, and Type III by the absence of discernable shear bands. Optical microscopy reveals shear cracks in both Type I and Type II, with those in Type II being significantly narrower than in Type I. A prominent microscopic feature of Type III is pressure-induced grain crushing. The transition among failure modes is closely related to the boundaries of the brittle-ductile domain. With increasing hydrostatic pressure, failure modes transition sequentially from Type Ⅰ to Type Ⅱ and then to Type Ⅲ, with clear pressure boundaries demarcating each mode.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111255"},"PeriodicalIF":4.7,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106838","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 tensile properties and fracture behaviors of coral aggregate concrete","authors":"Jiawen Wu ,&nbsp;Jiajun Deng ,&nbsp;Linjian Ma ,&nbsp;Liqun Duan ,&nbsp;Cong Zhou ,&nbsp;Tao Chen","doi":"10.1016/j.engfracmech.2025.111252","DOIUrl":"10.1016/j.engfracmech.2025.111252","url":null,"abstract":"<div><div>As an alternative building material, the feasibility of coral aggregate concrete has been widely recognized for the engineering construction on reef islands. To explore the tensile properties and fracture behaviors of coral aggregate concrete, the splitting tension tests were conducted utilizing an MTS testing machine and a split Hopkinson pressure bar (SHPB) device. The changes in tensile strength and failure strain, energy dissipation, and failure pattern of coral aggregate concrete with respect to strain rate were systematically analyzed. The results show that the dynamic tensile strength of coral aggregate concrete is more dependent on the loading strain rate than conventional concrete and cement mortar. The tensile failure strain increases nonlinearly with an increase in strain rate and tends to an upper limit. Likewise, the energy absorption increases with increasing strain rate, which is mainly consumed by generating more fracture planes leading to more damage and fragmentations of coral aggregate concrete. And the splitting tensile fracture always penetrates directly through the coral aggregates. Furthermore, a real mesostructure concrete modelling was developed to characterize the fracture behaviors of coral aggregate concrete. The node-split method and damage failure method were combined to effectively capture the crack and fracture process. The mesoscopic simulation elucidated the influence of the low-strength large coral aggregate and porous mortar matrix on the dynamic fracture behaviors. Lastly, a strength-ratio-based approach for brittleness analysis indicates the brittleness of coral aggregate concrete is less than that of conventional concrete with approximate strength grade under dynamic loading.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111252"},"PeriodicalIF":4.7,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090464","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":"Grain size effect on rockburst in granite: Evidence from true triaxial tests and grain‑based numerical simulations","authors":"Kang Peng ,&nbsp;Tao Wu ,&nbsp;Xu Liu ,&nbsp;Kun Luo ,&nbsp;Song Luo ,&nbsp;Zhiyong Zhou","doi":"10.1016/j.engfracmech.2025.111253","DOIUrl":"10.1016/j.engfracmech.2025.111253","url":null,"abstract":"<div><div>To investigate the grain size effect on rockburst characteristics, sets of true triaxial tests were conducted on fine-grained and coarse-grained granite specimens featuring arched hole. Throughout the testing process, acoustic emission (AE) monitoring and video surveillance were simultaneously implemented to capture real-time data. Meanwhile, based on the Grain-Based Model (GBM), the Particle Flow Code in Three Dimensions (PFC^3D) was employed to simulate the failure of granite specimens, and the influence of grain size on the mechanical properties of granite was further revealed by Scanning Electron Microscopy (SEM). The results indicate that, under similar loading conditions, the fine-grained granite primarily undergoes slabbing failure without significant flake ejection. In contrast, the coarse-grained granite primarily undergoes rockburst with particle ejection, and the particle ejection process is relatively continuous over time. The AE activity of fine-grained granite is concentrated, with almost no AE signals appearing before step loading, and strong AE signals appear when slabbing failure occurs on arched hole wall. For the coarse-grained granite, the AE activity is temporally dispersed and active throughout the whole loading process. It is also found that the GBM-PFC^3D simulations are in good agreement with the laboratory test results. The total number of microcracks in the coarse-grained granite is higher than that in the fine-grained granite. In the fine-grained granite, the stress distribution around the arched hole and arched hole wall is relatively uniform, and the microcrack propagation paths are orderly. The SEM results show that the internal microcracks in the fine-grained granite always expand in a straight line, whereas the expansion path of microcracks inside the coarse-grained granite is always influenced by stress concentration and turns around. SEM analysis of granite debris validated the microcrack propagation patterns observed in numerical simulations.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111253"},"PeriodicalIF":4.7,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123867","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":"Three-dimensional phase-field modeling of the fracture constraint effects in Ti6Al4V alloy fabricated by laser powder bed fusion","authors":"Yingmeng Xiao ,&nbsp;Jingyu Sun ,&nbsp;Filippo Berto ,&nbsp;Guian Qian","doi":"10.1016/j.engfracmech.2025.111221","DOIUrl":"10.1016/j.engfracmech.2025.111221","url":null,"abstract":"<div><div>The effect of constraint on fracture toughness is a critical issue in assessing the integrity of engineering structures. The brittle phase-field model (PFM) for fracture has been extended to the elastic–plastic solids. This study aims to enhance the understanding of constraint effects on the fracture behavior of an additively manufactured Ti6Al4V alloy. The fracture behavior of three-dimensional (3D) compact tension (CT) specimens with varying crack lengths and thicknesses is investigated experimentally and numerically. The results demonstrate that phase-field modeling is an effective tool for evaluating the fracture constraint effects of 3D cracked metalic material under mode I loading. With a single set of parameters, the elastic–plastic PFM accurately captures both the peak load and the post-peak softening behavior of specimens subjected to different constraint levels. While the elastic PFM can adequately assess peak loads in elastic–plastic materials, it lacks the capability to replicate the softening curve of the material. Loading affects in-plane constraints more than out-of-plane constraints, and the smaller the in-plane constraints, the higher the specimen fracture toughness and the longer the crack extension under the same loading conditions. In addition, the PFM can capture the necking effect at the crack tip and the crack propagation profiles, in particular, crack nucleation, propagation and even branching on the specimen surface can be accurately and effectively predicted by the elastic–plastic PFM. This work is beneficial in determining the fracture toughness of 3D elastic–plastic materials under different levels of constraint and demonstrates the feasibility of using PFM to study the fracture behavior of complex structures in the future.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"324 ","pages":"Article 111221"},"PeriodicalIF":4.7,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106837","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}