Engineering Fracture Mechanics最新文献

{"title":"Initiation and propagation of small fatigue cracks in shales containing inclined bedding planes","authors":"Yuanxun Nie ,&nbsp;Xishu Wang ,&nbsp;Bisheng Wu","doi":"10.1016/j.engfracmech.2025.111515","DOIUrl":"10.1016/j.engfracmech.2025.111515","url":null,"abstract":"<div><div>The inclined bedding plane is one of the most common geological characteristics in shale reservoirs. Due to the low permeability of shales, hydraulic fracturing (HF) is widely used in shale reservoirs, but the complexity of the crack network is limited by the inclined bedding planes. A method to increase the number of cracks and enhance their connectivity is needed for shale reservoirs. This study proposes a fatigue loading method to fracturing the shale samples with different dip angles (the complementary angle of the angle between the bedding planes and the prefabricated notch in shale samples), whose effectiveness was validated by the <em>in-situ</em> SEM three-point bending tests. The experimental results showed that the average peak tensile stress for the samples containing bedding plane at a dip angle of 30°, 60° and 90° is only 40.67%, 13.74% and 8.79%, respectively, of the peak tensile stress observed for the samples with a dip angle of 0°. Comparing the initiation and propagation characteristics of small cracks (SCs) under monotonic and fatigue loadings, the fatigue loading method increases the number of artificial cracks by five times. Additionally, the fatigue loading method was useful for enhancing the connectivity between adjacent cracks due to more damage induced along the maximum shear stress direction. Finally, the SC surface morphologies under different loading methods were compared and it is found that the fatigue shear stress along the bedding plane decreases the roughness of the wavy SC surface. This study sheds light on understanding the influence of fatigue loading on SC initiation and propagation, which may thus be used for facilitating HF treatments in shale oil/gas reservoirs containing inclined bedding planes.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111515"},"PeriodicalIF":5.3,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916614","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":"Integrating physics-informed symbolic regression with finite element models for damage law discovery","authors":"Mohammad Zhian Asadzadeh ,&nbsp;Jakob Bialowas ,&nbsp;Zain Ali ,&nbsp;Dietmar Gruber ,&nbsp;Hans-Peter Gänser","doi":"10.1016/j.engfracmech.2025.111501","DOIUrl":"10.1016/j.engfracmech.2025.111501","url":null,"abstract":"<div><div>Numerical simulation of fracture behavior in materials is a complex and challenging task. Accurate modeling of nonlinear mechanical behavior in systems affected by degradation and fracture relies on implementing suitable damage models within finite element methods (FEMs). This study explores the integration of physics-informed symbolic regression (SR) with FEM to derive an analytical damage law directly from experimental wedge splitting test data. Using genetic programming operations, a population of candidate damage equations evolves over hundreds of generations to identify the best fit to the measured load–displacement (F-D) data. Our findings demonstrate that the SR method yields a damage model that balances both accuracy and interpretability. Additionally, we discuss the efficiency and challenges associated with integrating SR with FEM, highlighting its potential for practical engineering applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111501"},"PeriodicalIF":5.3,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916739","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 Coupled Criterion-based approach to develop an adherence test for adhesively bonded joints","authors":"Pierre Bidaud ,&nbsp;Thomas Bonnemains ,&nbsp;Eric Lolive ,&nbsp;Nicolas Carrere","doi":"10.1016/j.engfracmech.2025.111493","DOIUrl":"10.1016/j.engfracmech.2025.111493","url":null,"abstract":"<div><div>In this study the authors propose a test specimen developed to study both failure initiation and crack propagation at the interface with the aim to determine its strength and toughness. The two-substrate specimen used was bonded with a thin joint of structural adhesive, to conform to most of the industrial applications. Then, geometry of the specimen and parameters of the four-point bending was designed to locate failure initiation at one interface and in order to have a stable evolution of the crack propagation at this interface. This optimization work was performed using 3D Finite Element Model for an interface of metallic substrates and an industrial epoxy based adhesive. An experimental campaign was carried out on the optimized configuration of the specimen and the four-point bending flexural loading.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111493"},"PeriodicalIF":5.3,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908316","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 mechanism of filling layer self-compacting concrete before and after polymer repair in CRTS-III track slabs","authors":"Leiyang Pei ,&nbsp;Lei Qin ,&nbsp;Zhiwen An ,&nbsp;Xuanxuan Chu ,&nbsp;Zhichuang Shi ,&nbsp;Feifan Shi ,&nbsp;Fengyuan Li ,&nbsp;Chengchao Guo","doi":"10.1016/j.engfracmech.2025.111497","DOIUrl":"10.1016/j.engfracmech.2025.111497","url":null,"abstract":"<div><div>The post-poured filling layer self-compacting concrete (FLSCC) in the China Railway Track System-III (CRTS-III) may be subjected to fractures under high-speed train loads. These fractures would seriously affect the operation of track systems and need to be repaired timely. However, the performance improvement mechanisms and the fracture characteristics of polymer-repaired FLSCC have rarely been studied. Thus, this study focused on investigating the fracture characteristics of FLSCC specimens before and after repairing using acoustic emission (AE) and scanning electron microscope (SEM) techniques through three-point bending (TPB) tests. The results indicated that the carrying capacity and ductility of the specimens were improved by 1.2 and 1.4 times after repair, respectively. Both types of specimens ultimately failed due to the FLSCC fracture, with distinct failure mechanisms. For instance, the specimen toughness doubled after repair based on the calculated fracture parameters. The critical crack extension rate of the repaired specimens was 3 times higher than that of the original ones. Consequently, the AE events detected in the repaired specimens were twice as large as those in the original ones. Meanwhile, the repaired specimens produced a large magnitude of b-value fluctuations and released more AE energy with increasing loads. Additionally, the penetrating, bonding, coating and filling effects of the repair polymer observed by micro-analysis improved the fracture performance by interlocking structures. A Mode-I fracture model considering repairing effects was proposed and validated. The results could provide better retrofitting suggestions for the operation and maintenance of CRTS-III.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111497"},"PeriodicalIF":5.3,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144912731","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 adhesion response of elastomers with square and circular cross-sections","authors":"ZiJian Chen ,&nbsp;TianYan Gao ,&nbsp;Tao Wang ,&nbsp;Yang Zhao ,&nbsp;Ping Gu","doi":"10.1016/j.engfracmech.2025.111508","DOIUrl":"10.1016/j.engfracmech.2025.111508","url":null,"abstract":"<div><div>The dynamic adhesion performance of adhesive materials has drawn a lot of attention. Under dynamic adhesion, there is a competition between two types of indicators: the force-related indicators (pull-off force <em>P</em>_c and work of adhesion <em>W</em>_ad) and the holding-adhesion indicators (delamination time <em>T</em>_c and impulse of adhesion <em>I</em>_ad). The dynamic adhesion response of these four key parameters of square and circular cross-section elastomers will be examined in this research. Based on the correlation between the work of adhesion per unit area and the crack propagation rate, as well as the similarity of the delamination processes at various pulling speeds, the theoretical power function relationship between the above four adhesion parameters and pulling speed <em>v</em>_pull is derived: <em>P</em>_c ∝ <em>v</em>_pull<em>ⁿ</em>^/(2+<em>ⁿ</em>⁾, <em>W</em>_ad ∝ <em>v</em>_pull²<em>ⁿ</em>^/(2+<em>ⁿ</em>⁾, <em>T</em>_c ∝ <em>v</em>_pull^-2/(2+<em>ⁿ</em>⁾, <em>I</em>_ad ∝ <em>v</em>_pull⁽<em>ⁿ</em>^-2)/(2+<em>ⁿ</em>⁾. Here, <em>n</em> is the exponential of the crack propagation rate in the Gent-Schultz law, reflecting the energy dissipation during the elastomer’s dynamic adhesion. The above theoretical power function relationship successfully describes the experimental results of elastomers with circular and square cross-sections, including center and edge delamination modes. Furthermore, a conservative prediction of the maximum speed for unconstrained dynamic adhesion is given based on the relationship between <em>I</em>_ad and <em>v</em>_pull. These findings are expected to provide theoretical insights to guide the dynamic application of adhesive materials.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111508"},"PeriodicalIF":5.3,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896710","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":"Finite element analysis of the asymmetric ENF test specimen","authors":"J. Bonhomme ,&nbsp;V. Mollón","doi":"10.1016/j.engfracmech.2025.111504","DOIUrl":"10.1016/j.engfracmech.2025.111504","url":null,"abstract":"<div><div>The objective of this article is to investigate the asymmetric end notched flexure (AENF) test. The AENF test specimen consists of two sublaminates with different stiffnesses (dissimilar elastic properties and/or thicknesses). A key observation in this test is that AENF test specimens exhibit different fracture behaviour depending on their positioning in the test. Depending on the position of the stiffer sublaminate, ‘local contact’ or ‘global contact’ may occur along the cracked arms giving rise to different contact pressure distribution. This variation in the contact pressure distribution leads to different fracture behaviour at the crack tip: mixed-mode I/II or pure mode II. This work demonstrates that a straightforward experimental or numerical compliance calibration (CC) procedure can effectively determine the total energy release rate (ERR) in mixed-mode conditions (<em>G</em>​=<em>G_I</em>​+<em>G_II</em>​) or the mode II component (<em>G_II</em>​) when pure mode II is present, depending on the positioning of the specimen. The criterion established by other authors under which the AENF test configuration exhibits pure mode II at the crack tip was also reviewed. In this case, analytical formulations developed by other authors were compared with the CC procedure and the virtual crack closure technique (VCCT). Finally, this article examines the influence of several test parameters on the mode mixity. These parameters include the specimen degree of asymmetry, the initial crack length, and the degree of the deformation applied during the test. The entire investigation was conducted using the finite element method (FEM).</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111504"},"PeriodicalIF":5.3,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896751","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":"Liquid metal embrittlement of Cu-30%Zn by EGaIn: Microscale fracture toughness by in situ SEM testing","authors":"Marco Ezequiel ,&nbsp;Eva Héripré ,&nbsp;Ingrid Proriol Serre ,&nbsp;Thierry Auger","doi":"10.1016/j.engfracmech.2025.111505","DOIUrl":"10.1016/j.engfracmech.2025.111505","url":null,"abstract":"<div><div>Liquid Metal Embrittlement (LME) of Cu-30 %Zn brass induced by liquid Ga-In eutectic (EGaIn) is investigated through a novel approach that combines <em>in situ</em> scanning electron microscopy (SEM) and micromechanical testing. Unlike macroscopic measurements, at a small scale, the crack initiation process can be sufficiently monitored such that a crack initiation fracture toughness can be derived using Finite Element Modeling (FEM) both at the continuum level or within a Crystal Plasticity framework (CPFEM). Using this new analysis methodology, the measured fracture initiation toughness values, <em>K_Jc</em> = 2.00 (FEM) and 2.36 MPa·m^½ (CPFEM), are found to be considerably lower than the ones previously measured in the LME literature, thanks to the minimization of plastic zone size effects. These results highlight the critical role of real-time observations in capturing crack nucleation and open a pathway for direct comparison with atomistic fracture models.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111505"},"PeriodicalIF":5.3,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907767","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":"Microseismic response characteristics of overlying strata failure and unusual gas emissions in deep mining","authors":"Erhui Zhang ,&nbsp;Hongqing Zhu ,&nbsp;Jinhai Liu ,&nbsp;Linsheng Gao","doi":"10.1016/j.engfracmech.2025.111498","DOIUrl":"10.1016/j.engfracmech.2025.111498","url":null,"abstract":"<div><div>Unusual gas emissions constitute a critical dynamic hazard threatening mining safety. Severe fracturing within the overlying strata during deep mining substantially increases the likelihood of such incidents. A high-precision microseismic monitoring system was employed to investigate the spatiotemporal distribution and evolution patterns of microseismic events during mining operations at the 1200 mining face in Shanxi, China. This approach enabled analysis of the dynamic microseismic response characteristics linked to overlying strata fracturing and unusual gas emissions during deep mining. Microseismic events exhibited high-density distribution within 0–20 m above the coal seam, low-density distribution between 20–80 m above the seam, and within 0–10 m below the floor. Thirty-six percent of microseismic events had counts between 10 and 30, whereas 24 % ranged from 30 to 60 events. Additionally, 72.3 % of microseismic events had energies concentrated within 10³ to 10⁴ J. The caving zone (0–16 m above the coal seam) displayed microseismic events distributed laterally across its extent; this zone exhibited an intense microseismic response and high event concentration. The fracture zone (16–39 m above the seam) contained fewer microseismic events, though distribution was relatively concentrated. Within the bending subsidence zone, the microseismic response was weak, with events being scattered and infrequent. Utilizing the minimum cumulative energy threshold (9.8 × 10⁵ J) of microseismic events intercepted by the roof, we determined the advance influence distance of overlying strata fractures to be 5–20 m. Patterns of unusual gas emissions showed correlation with microseismic event magnitude, location, and distribution density across the area. This study was designed to reveal the intrinsic relationship between overlying strata fracturing and unusual gas emissions. The findings are expected to provide effective early warning systems and control strategies, facilitate real-time monitoring of mine safety, mitigate catastrophic accidents, and safeguard miners’ lives. These results offer a novel perspective on coal-rock failure–gas emission relationships at high-gas mining faces, enhancing gas prevention measures and overall mine safety.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111498"},"PeriodicalIF":5.3,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908315","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":"Fatigue life prediction of ultrasonic impact treatment aluminum alloy weld joint based on the continuous damage model and artificial neural network","authors":"Jiahui Cong ,&nbsp;Zhuo Liu ,&nbsp;Song Zhou ,&nbsp;Xuyang Zhu ,&nbsp;Shoulong Gao","doi":"10.1016/j.engfracmech.2025.111503","DOIUrl":"10.1016/j.engfracmech.2025.111503","url":null,"abstract":"<div><div>In this paper, fatigue tests were conducted on specimens of 2024-T4 aluminum alloy weld joint before and after ultrasonic impact treatment (UIT). The test results show that after UIT, the fatigue life of the specimens significantly increased under identical stress levels (Δσ of 200 MPa, 175 MPa, 150 MPa, and 125 MPa), all reaching 10⁷ cycles, indicating a substantial increase in the fatigue limit of the specimens. Building on these findings, a new model for studying fatigue life was employed, effectively integrating Continuous Damage Mechanics (CDM) theory with Artificial Neural Networks (ANN). Initially, a CDM model considering residual stresses was developed theoretically, and fatigue life was numerically calculated based on this model. More than 400 sets of data were collected to train the ANN; subsequently, predictions and validations of fatigue life were performed. The research results demonstrate that the proposed predictive model can accurately evaluate the effect of UIT on the fatigue life of 2024-T4 aluminum alloy welded joint specimens, showcasing its effectiveness and applicability in predicting fatigue behavior.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111503"},"PeriodicalIF":5.3,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896754","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":"Model testing and numerical study on directional fracture induced by arc-shaped charge hydraulic blasting","authors":"Guoqing Xu ,&nbsp;Junmu Wang ,&nbsp;Hongtao Li ,&nbsp;Mengnan Shi ,&nbsp;Jun Zeng ,&nbsp;Qiang Yao","doi":"10.1016/j.engfracmech.2025.111500","DOIUrl":"10.1016/j.engfracmech.2025.111500","url":null,"abstract":"<div><div>Directional fracture-controlled blasting technology is widely applied in rock excavation projects; however, traditional pre-splitting blasting and smooth blasting are increasingly struggling to fulfill the engineering demands posed by complex geological conditions, prompting the emergence of various directional fracturing blasting techniques. An arc-shaped charge hydraulic blasting technology integrating slit-cutting, shaped charge, and water-pressure blasting mechanisms is proposed. Pre-split directional notches are formed along the borehole wall using shaped charge blasting, while water medium is employed to enhance detonation energy utilization and promote crack propagation along the predetermined notch direction. A two-dimensional blasting model test apparatus was developed in this study, which fully incorporates the quasi-static effects of detonation gases. Directional fracture mechanisms of arc-shaped charge hydraulic blasting were investigated through scaled model tests, with experimental results validated and supplemented by dynamic finite element numerical analysis. Experimental results demonstrate that the quasi-static effect of detonation gases plays a crucial role in crack propagation. During two-dimensional blasting tests, it is essential to constrain the venting of detonation gases along the outward normal direction of the specimen surface. Compared with the air medium, the peak strain under the condition of complete water medium is increased by 37.6%, and the crushing area is increased by 60 %; However, water is uniformly distributed when transmitting explosion load, so it has no directional crack effect. Compared to air medium, when water was placed on the non-shaped-charge side of the liner charge while maintaining a jet slit in the shaped-charge direction, the peak borehole wall pressure in the shaped-charge direction increased by 47%, with 20% greater main crack length. The borehole wall on the non-shaped charge side remained intact, and fracture length on this side decreased by 45%. The study elucidates the directional fracturing mechanism of arc-shaped charge hydraulic blasting and experimentally validates its effectiveness, providing a novel strategy for contour control in underground engineering blasting excavation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"327 ","pages":"Article 111500"},"PeriodicalIF":5.3,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144889860","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}