Engineering Fracture Mechanics最新文献

{"title":"The mechanism of rock-breaking using disc cutter assisted by pre-slotting","authors":"Congcong Gu ,&nbsp;Wenjie Bao ,&nbsp;Xiaodi Zhang ,&nbsp;Fuyou Chen ,&nbsp;Hongxiang Jiang ,&nbsp;Songyong Liu","doi":"10.1016/j.engfracmech.2025.111165","DOIUrl":"10.1016/j.engfracmech.2025.111165","url":null,"abstract":"<div><div>To reveal the rock-breaking mechanism under the pre-slotting assisted disc cutter, an experimental study on rock breaking was conducted based on a disc cutter linear cutting test bench. The relationships between the cutting force, specific energy consumption (SE), rock debris distribution parameters (roughness index <em>CI</em>, uniformity coefficient <em>n_b</em>, characteristic particle size <em>r_e</em>, and fractal dimension <em>D_f</em>) and the pre-slotting depth were analyzed. Additionally, the relationship between SE and rock debris distribution parameters was further investigated. Meanwhile, a two-dimensional discrete element model for the pre-slotting assisted disc cutter rock breaking was established. The rock-breaking mechanism under the presence or absence of pre-slotting was revealed from the perspectives of crack number, crack propagation trend, and internal stress distribution within the rock. The results show that as the pre-slotting depth increases, the rock-breaking force of the disc cutter first decreases and then increases. The SE exhibits a trend of first decreasing and then increasing with the increase in pre-slotting depth. The presence of the pre-slotting can effectively reduce the rock-breaking force on the cutter (up to 58 % reduction in the normal force, and 51 % in the rolling force) and significantly decrease the SE required for rock breaking (up to an 88 % reduction in SE). SE decreases following a power function trend with the increase in <em>CI</em> and <em>r_e</em>, while it increases with <em>D_f</em> and <em>n_b</em>, following power and linear growth trends, respectively. From the strength of the correlation between SE and rock debris (<em>CI</em> &gt; <em>n_b</em> &gt; <em>r_e</em> &gt; <em>D_f</em>), it can be seen that <em>CI</em> is a reasonable debris distribution parameter, which can be used to assess the SE and rock-breaking efficiency of the disc cutter. The distribution trend of crack number can effectively reflect the variation of the cutter’s cutting force. The larger the ratio of tensile cracks to shear cracks, the smaller the cutting force required for rock breaking by the disc cutter. An appropriate pre-slotting depth can effectively guide the crack propagation direction and reduce the number of cracks, thereby improving the fragmentation size of the rock debris. Under the condition without pre-slotting, rock fragmentation is primarily dominated by shear failure driven by compressive stress, while under the condition with pre-slotting, rock fragmentation is mainly dominated by tensile failure driven by tensile stress.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111165"},"PeriodicalIF":4.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868195","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":"Systematic study of bonding behavior at the aggregate-mortar interface: Analysis based on experimental and numerical models","authors":"Yang Liu ,&nbsp;Jianghong Mao ,&nbsp;Yangqing Liu ,&nbsp;Lei Zhou ,&nbsp;Feng Dai ,&nbsp;Zhibing Luo ,&nbsp;Meng Yuan","doi":"10.1016/j.engfracmech.2025.111151","DOIUrl":"10.1016/j.engfracmech.2025.111151","url":null,"abstract":"<div><div>The bond behavior at the aggregate-mortar interface plays a crucial role in determining the mechanical properties and durability of concrete, especially under environmental stressors such as freeze–thaw cycles and abrasion. This study simulates the bond performance of aggregates in concrete by analyzing the bonding behavior between steel semi-ellipsoidal aggregate and mortar, aiming to explore the different contributions and influencing factors of tensile and shear bond forces at the interface. Using a combination of numerical simulation, theoretical analysis, and model test, the research investigates the variation of interface bond strength at different curing ages and assesses the applicability of the traction-separation law and bilinear cohesive zone model for describing steel aggregate bonding behavior in concrete. The research results demonstrate that the contributions of tensile and shear bond strengths to the bonding behavior are influenced by the geometric shape of the aggregate and the interface conditions. As the aggregate aspect ratio (<em>a</em>/<em>c</em>) increases from 0.4 to 2.2, the simulated stiffness values rise from 46.76kN/mm to 82.19kN/mm, the pull-out force initially decreases and then increases, and the displacement at the point of maximum pull-out force reduces from 0.075 mm to 0.015 mm. This study provides a new perspective for analyzing the mechanical behavior of the concrete interface transition zone and offers insights for related research areas such as freeze–thaw and abrasion resistance.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111151"},"PeriodicalIF":4.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860595","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 peridynamics approach for modelling hydrogen- and oxidation-assisted fatigue crack growth","authors":"Shengbao Lu,&nbsp;Shenguang Liu,&nbsp;Xing Zhang,&nbsp;Liguo Zhao","doi":"10.1016/j.engfracmech.2025.111139","DOIUrl":"10.1016/j.engfracmech.2025.111139","url":null,"abstract":"<div><div>High performance superalloys, when exposed to gases such as hydrogen and oxygen, experience material embrittlement and a significant increase in the rate of fatigue crack growth, thereby reducing the service life of their structural components. In this study, a peridynamics model was developed to simulate fatigue crack growth in a nickel-based superalloy exposed to hydrogen and/or oxygen environments. The model leverages on the non-local characteristics of peridynamics theory to simulate the growth of fatigue cracks, while also accounting for hydrogen embrittlement and/or oxidation damage. The model’s capability and reliability were verified by comparing a series of simulation results with experimental data available in literature. Furthermore, this paper also explores the effects of loading frequency and degradation factor on the simulated results of fatigue crack growth. The peridynamics model provides an alternative and effective method for simulating and predicting fatigue crack growth in corrosive gas environment, which can be potentially applied to structural integrity assessment of gas turbine systems.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111139"},"PeriodicalIF":4.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855442","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":"Rupture directivity and poroelastic coupling in earthquakes induced by fluid injection","authors":"Sandro Andrés ,&nbsp;David Santillán ,&nbsp;Juan Carlos Mosquera ,&nbsp;Luis Cueto-Felgueroso","doi":"10.1016/j.engfracmech.2025.111123","DOIUrl":"10.1016/j.engfracmech.2025.111123","url":null,"abstract":"<div><div>Earthquakes induced by the human-made injection or extraction of fluids have recently become a major concern in energy technologies. When frictional and hydromechanical conditions lead to fault reactivation, unstable slip can occur and rupture propagates across the fault with a pattern analogous to two crack tips, spreading away from the hypocenter. During the earthquake the rupture tips can propagate symmetrically or along a preferred direction. These propagation patterns are related with the effects of the earthquake, and are essential due to the predominance of almost-unilateral ruptures in large earthquakes catalogs.</div><div>We study how poroelastic coupling controls the directivity of the rupture in earthquakes induced by pore pressure changes. The directivity patterns observed in earthquakes ruptures may be explained by a contrast in material properties across the fault as previous studies have shown. Here we show that rupture asymmetries may be also promoted by the pressure and stress changes induced by fluid injection prior to rupture, together with the undrained pressure response during coseismic slip. We employ fully coupled hydromechanical simulations of poroelastic media with rate-and-state faults, and analytical solutions to perform a dimensionless analysis. We observe that, depending on the flow conditions and the initial fault stress state, directivity patterns range from almost-symmetric to almost-unilateral.</div><div>We explain the rupture directivity pattern in terms of the conditions of fault confinement and pore pressure diffusion, and identify two mechanisms that control the symmetry of the earthquake rupture. Firstly, the pore pressure distribution prior to earthquake, which depends on the distance between the injection well and the fault, controls the heterogeneity of fault strength along the fault. Secondly, the undrained effect due to coseismic fault slip, which is directly related to the initial confinement, causes an increase or decrease of pore pressure on either side of the fault.</div><div>Our results contribute to understand the impact of poroelasticity on rupture directivity in injection-induced earthquakes and offer a feasible explanation of almost-unilateral rupture patterns.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111123"},"PeriodicalIF":4.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864467","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":"Magnetic flux leakage testing based on the dual testing probes resisting the negative effects of lift-off perturbations","authors":"Shuai Hao ,&nbsp;Peng-Peng Shi ,&nbsp;San-Qing Su","doi":"10.1016/j.engfracmech.2025.111141","DOIUrl":"10.1016/j.engfracmech.2025.111141","url":null,"abstract":"<div><div>The traditional defect evaluation method for magnetic leakage flux (MFL) testing is based on the calibration relationship of signal characteristics on a given lift-off value. The unavoidable lift-off perturbations during the testing process cause changes in the collected MFL signals, leading to challenges in the quantitative evaluation of defect sizes by the traditional method. To address this, we propose an MFL testing system with dual testing probes to test signals containing lift-off information, and develop related algorithms with the Regulargridinterpolator function and particle swarm optimization method to achieve joint high-precision evaluation for radius and depth of defect in the presence of lift-off perturbations. Unlike the single testing probe used in the traditional evaluation method, stacked dual testing probes with a given lift-off difference and a self-developed experimental system for the MFL testing are prepared and optimized, realizing the jointly automatic and continuous acquisition of two sets of signals with a given lift-off difference. Then, the testing experiment of Q235 steel plate containing surface round hole defects (defect radius and depth are 2 mm ∼ 5 mm and 1 mm ∼ 5 mm) is executed, and the experimental results combined with the magnetic dipole model show that both sets of signals are positively correlated with the defect size and closely related to the lift-off value. In addition, the proposed defect evaluation algorithm is used to jointly quantitatively evaluate the radius and depth of surface round hole defects based on the collected MFL testing signals, where the prediction error of defect size based on dual testing probes is controlled within 0.4 mm, indicating that the evaluation capability is significantly higher than that from the traditional evaluation method based on the single testing probe in the presence of lift-off perturbations. The proposed method is demonstrated to resist the negative effects of lift-off perturbations, providing a pathway for the quantitative evaluation of defects under complex testing conditions.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111141"},"PeriodicalIF":4.7,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860594","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 novel structural stress method and stress intensity factor solutions for fatigue analysis of high-strength bolted connections in bolted spherical joints","authors":"Saicong Guo,&nbsp;Xuanzhe Ji,&nbsp;Guoqing Wang,&nbsp;Xiaoling Liu,&nbsp;Hanchao Liu,&nbsp;Honggang Lei","doi":"10.1016/j.engfracmech.2025.111138","DOIUrl":"10.1016/j.engfracmech.2025.111138","url":null,"abstract":"<div><div>Both bolted connections and welded joints in construction engineering are susceptible to fatigue fracture. While the structural stress method has been relatively well-established for evaluating the fatigue behavior of welded joints, it remains unexplored for high-strength bolted connections. This paper presents a novel definition of structural stress and corresponding numerical methods for the fatigue analysis of high-strength bolted connections, based on the equilibrium equations of force and moment. The structural stress, composed of membrane and bending stresses, has shown significant insensitivity to element type and mesh size in both axisymmetric and three-dimensional solid models of bolted spherical joints. On this basis, stress intensity factor (SIF) solutions for bolt cracks based on structural stress have been proposed. This approach decomposes the SIF into membrane and bending stress components, allowing for the quantification of their individual contributions to fatigue life while also considering the effects of bolt specifications. Subsequently, the effects of bolt screwing depth and diameter on stress concentration and fatigue life were discussed. Research indicates that structural stress, which considers stress concentration and loading pattern, consolidates fatigue data across various screwing depths into a narrow range. The structural stress-based SIF considers the effects of stress concentration, bolt specification, and loading pattern, consolidating fatigue data from bolts with varying screwing depths and diameters into a narrow range, with a correlation coefficient of 0.862 and a standard deviation of 0.161. This study provides novel methods and insights for the fatigue assessment of high-strength bolts.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111138"},"PeriodicalIF":4.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the mechanical behavior of GLARE laminates under combined tensile-torsion","authors":"Ying Ai ,&nbsp;Jiucheng Zhao ,&nbsp;Liya Tian ,&nbsp;Shanyue Guan ,&nbsp;Zerui Zhao ,&nbsp;Xiangyu Zong ,&nbsp;Shizhong Zhang ,&nbsp;Hongwei Zhao","doi":"10.1016/j.engfracmech.2025.111142","DOIUrl":"10.1016/j.engfracmech.2025.111142","url":null,"abstract":"<div><div>Fiber metal laminates (FMLs) are extensively utilized as materials for fuselage skin panels in aircraft. Throughout the service life of an aircraft, these fuselage panels endure a range of complex loads, including tensile, bending, and torsional forces. The deformation and damage resulting from these complex loads lead to intricate failure mechanisms. To understand the damage and failure patterns of FMLs under such conditions, this study aims to investigate the mechanical behavior of glass fiber reinforced aluminum laminates (GLARE) under combined tensile-torsion (CTT) loads. The findings reveal that applying pre-torsion to the material significantly reduces its tensile properties. Specifically, when the material is subjected to a pre-torsion-tension (PTO) condition with a 45° pre-torsion angle, the material’s maximum tensile load decreases by 27.7 %, tensile strength drops by 27.6 %, and tensile strain declines by 44.9 % compared to pure tension. Conversely, when the material is subjected to a pre-tension–torsion (PTE) condition with a 500 N pre-tension load, the material’s maximum torque increases by 93.4 % compared to pure torsion. Additionally, when the material is subjected to a PTE condition with a 1500 N pre-tension load, the torsional stiffness rises by 29.3 %, while the torsional angle corresponding to the maximum torque decreases by 74.5 %. To further analyze these effects, digital image correlation (DIC) was used to monitor the distribution and evolutionary trend of strain on the specimen surface under different loading conditions. Scanning electron microscopy (SEM) was used to characterize the damage patterns in the fracture region of the specimens under different conditions. This research provides insights into the reliability assessment and structural optimization design of GLARE laminates, contributing to the advancement of materials used in aerospace applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111142"},"PeriodicalIF":4.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865015","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":"Analytical solution for the stress fields of a hypocycloidal hole with two radial cracks in an infinite plate","authors":"Shengfan Bi,&nbsp;Xiaoting Cui,&nbsp;Yong Huang,&nbsp;Hao Wang","doi":"10.1016/j.engfracmech.2025.111134","DOIUrl":"10.1016/j.engfracmech.2025.111134","url":null,"abstract":"<div><div>Hole structures are widely utilized in engineering applications. Edge cracks may form around holes during manufacturing or operation, potentially leading to structural failure. This study investigates the problem of unequal radial cracks emanating from a hypocycloid-shaped hole in a two-dimensional isotropic infinite plate. Using the Muskhelishvili approach and conformal mapping, a general solution is derived for cracked deltoid and astroid holes. The analytical theory is validated through finite element simulations, with numerical examples for both single-sided and double-sided radial cracks. The effects of crack length and hypocycloid geometry on the stress intensity factor (SIF) are investigated. Under uniaxial tension, an increase in crack length raises the SIF for both the corresponding and opposite crack tips. Due to geometric differences at the crack initiation location, cracks emanating from the cusps of a deltoid hole exhibit reduced sensitivity of SIF to crack length compared to cracks emanating from smoother hole edges.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111134"},"PeriodicalIF":4.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855441","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":"Evaluation of low-temperature fracture and damage of asphalt concrete using SCB test combined with DIC","authors":"Shangshu Zhu ,&nbsp;Zhengfeng Zhou ,&nbsp;Ze Zhang ,&nbsp;Zhenqi Liu ,&nbsp;Xiao Hou","doi":"10.1016/j.engfracmech.2025.111135","DOIUrl":"10.1016/j.engfracmech.2025.111135","url":null,"abstract":"<div><div>This study presents a method for assessing low-temperature damage and cracking in asphalt concrete by monitoring the surface displacement of semicircular bending (SCB) specimens during loading using digital image correlation (DIC) technology. The inflection point on the load line displacement (LLD)-crack tip opening displacement (CTOD) curve is used to identify the damage initiation, while the macroscopic crack morphology is employed to determine the critical fracture point. Based on the crack opening displacement measured along the crack propagation zone, damage evolution is quantified combining the linear softening cohesive zone model (CZM). Local and global damage factors are introduced to characterize the damage process. The results indicate that damage of asphalt concrete initiates before the peak load, occurring at approximately 90 % of the peak load at −10 °C. The horizontal displacement along vertical characteristic lines above the notch effectively evaluates the crack propagation behavior, providing a reliable approach for damage quantification in asphalt concrete.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111135"},"PeriodicalIF":4.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842919","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 toughness behavior of high-Ni/high-Mn Barsebäck 2 reactor pressure vessel welds after 28 years of operation","authors":"Sebastian Lindqvist,&nbsp;Noora Hytönen","doi":"10.1016/j.engfracmech.2025.111111","DOIUrl":"10.1016/j.engfracmech.2025.111111","url":null,"abstract":"<div><div>The safety assessment of reactor pressure vessels (RPV) is based on knowledge obtained from surveillance programs. In this study, the fracture toughness characteristics in the ductile-to-brittle transition region were determined for samples extracted from Barsebäck 2 RPV’s beltline and head high Ni/Mn welds, and the results were compared to the surveillance welds. The fracture toughness results from the surveillance program describe the RPV core welds after 28 years of operation associated to a fluence of 0.1·10¹⁹n/cm² in the beltline region. The results show that the microstructural features of the multilayer weld increase the uncertainty in the reference temperature T₀ to 34 °C. The inhomogeneity of the weld affects more the fracture toughness properties in comparison to impact toughness. The T₀ based embrittlement trend curve obtained for Barsebäck 2 weld subjected to a maximum fluence of 5.9·10¹⁹n/cm² is compared to similar welds. The results contribute to improvements in reliability of aging management programs of nuclear power plants important for availability of carbon free energy.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111111"},"PeriodicalIF":4.7,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842918","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}