Engineering Fracture Mechanics最新文献_第2页

Hydro-mechanical coupling non-uniform discretization peridynamics and its application in hydro-fracturing 水-力耦合非均匀离散周动力学及其在水力压裂中的应用

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-10-02 DOI: 10.1016/j.engfracmech.2025.111608

Er-Bao Du , Xiao-Ping Zhou

{"title":"Hydro-mechanical coupling non-uniform discretization peridynamics and its application in hydro-fracturing","authors":"Er-Bao Du , Xiao-Ping Zhou","doi":"10.1016/j.engfracmech.2025.111608","DOIUrl":"10.1016/j.engfracmech.2025.111608","url":null,"abstract":"<div><div>This paper proposes a hydro-mechanical coupling peridynamic model with non-uniform discretization, incorporating both constant and variable horizon approaches, to investigate hydraulic fracturing in rocks. The computational efficiency and accuracy of the two horizon schemes are systematically compared. The constant horizon method employs a uniform radius, simplifying implementation but leading to coarser crack representations and reduced efficiency in multi-field coupling. In contrast, the variable horizon approach dynamically adjusts the horizon radius, significantly reducing computational costs while improving crack resolution and coupling efficiency.</div><div>Several numerical examples are conducted to analyze key factors influencing hydraulic fracturing, validating the proposed model against conventional peridynamic methods and the continuous-discontinuous element method. The results demonstrate excellent agreement, confirming the model’s reliability. Notably, the study reveals that fracturing can occur even in intact materials without pre-existing cracks, though it requires higher injection pressure and longer initiation time. Furthermore, the shape of the water injection port and the arrangement of material points critically influence the fracture propagation path, particularly in cases involving circular injection ports. These findings provide new insights into rock fracturing mechanisms and offer a computationally efficient framework for simulating hydraulic fracturing in complex geological settings.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111608"},"PeriodicalIF":5.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264149","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}

引用次数: 0

Multiphase flow and heat transfer-driven fracture in saturated buffers for a nuclear waste repository: A novel phase-field cohesive zone model 核废料储存库饱和缓冲层中多相流和传热驱动断裂：一种新的相场内聚区模型

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-10-01 DOI: 10.1016/j.engfracmech.2025.111589

Jia Liu , Weihua Li , Qi Zhang , Yifeng Hu , Shengfei Cao , Jingli Xie

{"title":"Multiphase flow and heat transfer-driven fracture in saturated buffers for a nuclear waste repository: A novel phase-field cohesive zone model","authors":"Jia Liu , Weihua Li , Qi Zhang , Yifeng Hu , Shengfei Cao , Jingli Xie","doi":"10.1016/j.engfracmech.2025.111589","DOIUrl":"10.1016/j.engfracmech.2025.111589","url":null,"abstract":"<div><div>During the operational lifespan of high-level nuclear waste repositories, significant gas generation is anticipated through various physicochemical processes, including metal corrosion, water radiolysis, and microbial degradation. The subsequent migration of these gases through a saturated buffer poses significant challenges to the integrity of the engineering barrier. ‌Given the complex coupled interactions among gas, liquid, and solid phases within buffer materials during gas breakthrough processes under high-temperature environments, this study developed a novel phase-field cohesive zone model that captures fracture propagation jointly driven by multiphase flow, temperature, and pore pressure. The relative permeability contrast between the matrix and the fracture region is considered to capture the sustained gas breakthrough paths. The model demonstrates enhanced robustness through stabilized fluid source terms, particularly when employing low-order quadrilateral elements. Model validations are performed against both analytical solutions and numerical benchmarks. Field-scale simulations revealed that thermal effects on gas properties significantly accelerate gas breakthrough phenomena. The contact stiffness between the buffer material and the natural barrier has a significant impact on gas breakthrough, which is closely related to the rate of gas generation. Material heterogeneity governs preferential breakthrough pathways. This work establishes fundamental theoretical frameworks for optimizing buffer material composition and informing the design of deep geological repositories. The findings provide critical insights into gas migration mechanisms in nuclear waste containment systems.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111589"},"PeriodicalIF":5.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227540","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}

引用次数: 0

Crack propagation and distribution characteristics of deep-buried rock masses under water-coupled presplit blasting 水耦合预裂爆破下深埋岩体裂纹扩展及分布特征

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111600

Xiaofeng Huo , Xianyang Qiu , Xiuzhi Shi , Zhi Yu , Liyun Yang , Wenpeng Wei , Xiaoming Lou

{"title":"Crack propagation and distribution characteristics of deep-buried rock masses under water-coupled presplit blasting","authors":"Xiaofeng Huo , Xianyang Qiu , Xiuzhi Shi , Zhi Yu , Liyun Yang , Wenpeng Wei , Xiaoming Lou","doi":"10.1016/j.engfracmech.2025.111600","DOIUrl":"10.1016/j.engfracmech.2025.111600","url":null,"abstract":"<div><div>In deep rock blasting excavation, high in-situ stress often leads to difficulties in presplitting and poor contour quality, which affect engineering safety. To counteract the inhibitory effect of in-situ stress, water-coupled charge can be used due to its high energy transfer efficiency. In this study, an improved calculation model of crack propagation driven by the quasi-static pressure of explosion gas–water is proposed to analyze the crack propagation and coalescence under in-situ stress. Following, a three-hole numerical model is established to verify the theoretical results and investigate the inter-hole crack characteristics. The results show that the in-situ stress inhibits presplitting, while water is more conducive to presplitting than air, especially under high in-situ stress and low rock fracture toughness. The hole spacing and decoupling ratio should be reduced under high in-situ stress. Using water as the filling medium and aligning holes with the maximum principal stress significantly enhance the directional effect and are beneficial to rock damage control. Finally, optimization schemes are verified based on the excavation of deep-buried stopes. Evaluations of the 3D-scanned contour reveal that water and parallel layout increase the hole spacing by 20 % and 50 % respectively, while maintaining or even improving the contour quality.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111600"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264099","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}

引用次数: 0

Crack deflection in liquid crystal elastomers determined by energy release rate maximization: Experiments and simulations 由能量释放率最大化决定的液晶弹性体裂纹挠度：实验与模拟

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111602

Qiang Guo , Shengjia Zhang , Shengqiang Cai

{"title":"Crack deflection in liquid crystal elastomers determined by energy release rate maximization: Experiments and simulations","authors":"Qiang Guo , Shengjia Zhang , Shengqiang Cai","doi":"10.1016/j.engfracmech.2025.111602","DOIUrl":"10.1016/j.engfracmech.2025.111602","url":null,"abstract":"<div><div>This study investigates crack deflection in monodomain liquid crystal elastomers (LCEs) using a combined experimental and numerical approach. Fracture tests were performed on pure shear specimens with various initial mesogen orientations. Despite the pronounced anisotropy in stress–stretch behavior when mesogens are aligned parallel or perpendicular to the loading direction, the measured fracture toughness exhibits only a moderate dependence on orientation. Crack deflection was also characterized experimentally, revealing the influence of mesogen alignment on crack path deviation. To interpret the experimental observations, a finite element model incorporating the anisotropic constitutive behavior and mesogen reorientation of LCEs was developed to compute the energy release rate in cracked specimens. The model successfully predicted crack deflection by assuming propagation along the path of maximum energy release rate. These results provide critical insights into the fracture behavior of LCEs and offer guidance for the design of more robust LCE-based structures for diverse applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111602"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264161","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}

引用次数: 0

Numerical study on micro-cracking behavior and damage model for granite during thermal-cooling cycles 花岗岩热冷循环微裂纹行为及损伤模型数值研究

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111601

Shifeng Zhang , Yuqing Xu , Qinze Xing , Xinying Cui , Wenzhuo Ji , Jiabao Li

{"title":"Numerical study on micro-cracking behavior and damage model for granite during thermal-cooling cycles","authors":"Shifeng Zhang , Yuqing Xu , Qinze Xing , Xinying Cui , Wenzhuo Ji , Jiabao Li","doi":"10.1016/j.engfracmech.2025.111601","DOIUrl":"10.1016/j.engfracmech.2025.111601","url":null,"abstract":"<div><div>Deep energy exploitation involves heat exchange between fluids and rocks, where temperature variations can induce rock damage and lead to engineering challenges. In this study, a numerical rock core was established using a discrete element method (DEM)-based particle flow model to analyze the effects of mineral composition, heterogeneity, and particle size on microcrack development and mechanical behavior under heating–cooling thermal cycles. When the thermal heating temperature rises, thermal cracks evolve from intergranular tensile cracks to intragranular shear cracks within quartz grains. During cooling, intergranular tensile cracks are predominantly generated. Compared to heterogeneity and particle size, quartz content was the more important factor to affect the damage in mechanical property of rock after thermal cycles. Rocks with 70 % quartz content exhibit reductions in compressive strength and elastic modulus by 97.3 % and 98.2 %, respectively, after two cycles with cyclic temperature of 600 °C without confining, while when the confining pressure increased to be 120 MPa, rock compressive strength and elastic modulus reduce by 34.1 % and 30.9 %, respectively. Confining pressure can suppress crack numbers while the ratio of shear to tensile cracks increases. In this study, the Weibull function was verified to effectively characterize the evolution of rock thermal damage with respect to the maximum volumetric thermal strain. Confining pressure has a more significant influence on the damage model parameters than the microstructural factors. Our study results can provide theoretical support for rock mechanical property prediction after irregular thermal cycles damage, which is the basis for the safety analysis for engineering applications such as deep well drilling and geothermal energy exploitation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111601"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264095","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}

引用次数: 0

Experimental and numerical study on the loading rate effect of deep CRLD anchored soft rock 深部CRLD锚固软岩加载速率效应的试验与数值研究

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111594

Xiaoming Sun , Lei Wang , Li Cui , Yixiang Wen , Shuo Li

{"title":"Experimental and numerical study on the loading rate effect of deep CRLD anchored soft rock","authors":"Xiaoming Sun , Lei Wang , Li Cui , Yixiang Wen , Shuo Li","doi":"10.1016/j.engfracmech.2025.111594","DOIUrl":"10.1016/j.engfracmech.2025.111594","url":null,"abstract":"<div><div>The accelerated deformation effect of the surrounding rock in deep high-stress, strongly disturbed soft rock roadways is particularly pronounced, leading to frequent failures in anchoring system and surrounding rock instability. To address this issue, this paper conducts a comparative study through biaxial compression physical model experiments, examining the mechanical behavior and failure mechanisms of a novel constant-resistance large-deformation (CRLD) anchor cable and conventional high-strength (HS) anchor cable in anchoring soft rock under different loading rates. Experimental results indicate: As the loading rate increases, the peak strength, elastic modulus, and energy absorption values of both types of anchored rock gradually increase, while the residual strength shows a trend of first decreasing and then increasing. At high loading rates, the relative growth rates of mechanical parameters and energy absorption values in CRLD anchored rocks are significantly enhanced. Acoustic emission data indicate that, with increasing loading rates, the maximum count values and cumulative energy values of both types of anchored rock gradually increase, along with a relative increase in the number of high-count events. However, the overall distribution of counts in CRLD anchored rock is more uniform, the energy release process is smoother, and the acoustic emission characteristic values are significantly lower. Observations of failure characteristics reveal that, with increasing loading rates, the degree of crack development in CRLD anchored rock significantly increases, with the failure mode gradually shifting from a tensile crack-dominated to a shear crack-dominated tensile-shear mixed failure mode. Finally, based on the PFC-FLAC coupled numerical simulation method, a numerical model of CRLD anchored rock is constructed. Through statistical analysis of its mesoscopic damage evolution characteristics, the reliability of the physical model experimental results is validated.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111594"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264159","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}

引用次数: 0

Assessment for the service life of cable wire under corrosion fatigue coupling effect in extreme marine environment 海洋极端环境下腐蚀疲劳耦合作用下电缆导线使用寿命评估

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111603

Jian Guo , Jiaxuan Liu , Yile Zhong

{"title":"Assessment for the service life of cable wire under corrosion fatigue coupling effect in extreme marine environment","authors":"Jian Guo , Jiaxuan Liu , Yile Zhong","doi":"10.1016/j.engfracmech.2025.111603","DOIUrl":"10.1016/j.engfracmech.2025.111603","url":null,"abstract":"<div><div>With the widespread application of cable-stayed bridges, the issues of cable failure caused by atmospheric corrosion and vehicle alternating loads have received increasing attention. In the typical tropical marine environment, this failure is especially early to occur. To determine the service time in this condition, a simulation method for evaluating the service life of hot-dip galvanized steel wire and cable is proposed in a broad sense. The full lifecycle is divided into two stages: before crack propagation and after crack propagation. Therefore, the whole model includes model I and model II. The enhancement factor of fatigue on corrosion is obtained based on previous research for the model I. The enhancement factor of corrosion on fatigue is added into the paris formula for the model Ⅱ. Cellular automaton is used to simulate the corrosion developments of single steel and cable, verifying the accuracy of model I. Comparison of load cycle times calculated from model Ⅱ and the corrosion fatigue tests conducted by others before indicate that this model Ⅱ has accuracy over 90%. The novel fatigue life simulation of the cable is also completed by quantifying the progression relationship between corrosion and crack propagation, which has not been involved before.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111603"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227542","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}

引用次数: 0

The influence of specimen length on the residual stress and fatigue life 试样长度对残余应力和疲劳寿命的影响

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111581

Jorrit Rodenburg , Henk Slot , Sjoerd Hengeveld , Johan Maljaars

{"title":"The influence of specimen length on the residual stress and fatigue life","authors":"Jorrit Rodenburg , Henk Slot , Sjoerd Hengeveld , Johan Maljaars","doi":"10.1016/j.engfracmech.2025.111581","DOIUrl":"10.1016/j.engfracmech.2025.111581","url":null,"abstract":"<div><div>This paper studies the influence of specimen length on residual stress redistribution and fatigue life in welded cruciform joints made of steel grade S355. It uses numerical methods to simulate the common practice in fatigue testing, where specimens are cut from a larger welded plate assembly. A transient thermo-mechanical finite element model is used to simulate the welding and cutting processes, enabling a detailed analysis of residual stress relaxation due to reduced structural constraints when cutting the specimens. Fatigue life is assessed using linear elastic fracture mechanics, incorporating residual stress effects from the finite element simulations via a mean stress correction. Results show that shorter specimens exhibit reduced residual stress and increased fatigue resistance. For assemblies with a single pass weld, a minimum specimen length of 40 mm is recommended for deriving reliable S–N curves for welded joints in fatigue standards. The findings are in good agreement with experimental data and highlight the importance of specimen size in fatigue testing protocols.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111581"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227589","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}

引用次数: 0

Fracture simulation in hyperelastic materials and soft tissues by a novel finite strain smoothing gradient damage approach 基于有限应变平滑梯度损伤方法的超弹性材料和软组织断裂模拟

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-30 DOI: 10.1016/j.engfracmech.2025.111604

Chanh Dinh Vuong , Minh Ngoc Nguyen , Nhung Nguyen , Tinh Quoc Bui

{"title":"Fracture simulation in hyperelastic materials and soft tissues by a novel finite strain smoothing gradient damage approach","authors":"Chanh Dinh Vuong , Minh Ngoc Nguyen , Nhung Nguyen , Tinh Quoc Bui","doi":"10.1016/j.engfracmech.2025.111604","DOIUrl":"10.1016/j.engfracmech.2025.111604","url":null,"abstract":"<div><div>Fracture of hyperelastic materials and load-bearing soft tissues is particularly important to various biomechanical applications. The underlying knowledge and mechanisms associated with the initiation and evolution of crack, leading to (bio)material failure, have not been fully understood. We present a novel finite strain smoothing gradient-enhanced damage approach for modeling complicated fracture processes in isotropic/anisotropic hyperelastic materials, in particular, in rubber-like materials and aortic walls. Our recently developed smoothing gradient-enhanced damage model (SGDM), which owns several desirable features for modeling complicated fracture phenomena like crack-branching and mixed mode failure in brittle/quasi-brittle materials, is significantly extended to finite strain with a suitable constitutive model to capture the fracture in hyperelastic materials. For crack growth in arterial walls, the damage model accounts for both the elastin matrix and the anisotropy of the collagen fibers. Numerically, a second-order structural tensor that represents the orientation of collagen fibers is incorporated into the finite strain SGDM framework. The strain energy density is also mathematically augmented with a description of fibers, enabling a thorough investigation of anisotropic soft tissues. Numerical simulations of damage growth in rubber-like and aortic walls using the developed approach, are presented and analyzed. The computed results are thus compared with reference experimental and numerical solutions to show the accuracy and performance of the developed finite strain damage model.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111604"},"PeriodicalIF":5.3,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264093","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}

引用次数: 0

Mechanical and fracture behavior of coal under different loading modes: Experimental investigation on anisotropy and mixed-mode fracture toughness 不同加载模式下煤的力学与断裂行为：各向异性与混合模式断裂韧性试验研究

IF 5.3 2区工程技术

Engineering Fracture Mechanics Pub Date : 2025-09-29 DOI: 10.1016/j.engfracmech.2025.111597

Chaolin Wang, Wei Wang, Yu Zhao, Huasu Wang, Kun Zhang

{"title":"Mechanical and fracture behavior of coal under different loading modes: Experimental investigation on anisotropy and mixed-mode fracture toughness","authors":"Chaolin Wang, Wei Wang, Yu Zhao, Huasu Wang, Kun Zhang","doi":"10.1016/j.engfracmech.2025.111597","DOIUrl":"10.1016/j.engfracmech.2025.111597","url":null,"abstract":"<div><div>Coalbed methane (CBM) is an important unconventional natural gas resource whose efficient extraction relies heavily on understanding the fracture characteristics of coal reservoirs. This study investigates the mechanical behavior and fracture characteristics of bedded coal under varying loading modes using uniaxial compression, Brazilian splitting, and edge-notched disc bending (ENDB) tests. The results demonstrate that coal strength exhibits strong bedding-angle dependence, with tensile strength following a left-skewed S-shaped trend. ENDB tests reveal size-dependent fracture toughness: smaller specimens show greater resistance to Mode-III (tearing) fracture, while larger specimens favor Mode-I (tensile) resistance. The toughness index Rs increases from 1.38 (Mode-I) to 2.34 (Mode-III), reflecting rougher fracture surfaces and higher energy dissipation during torsional failure. Acoustic emission (AE) analysis further distinguishes tensile-dominated signals in Mode-I from shear-dominated signals in Mode-III loading. Bedding anisotropy strongly controls crack initiation, trajectory, and energy demand, with Mode-I governed by tensile opening and Mode-III involving torsional deformation with higher energy consumption. Despite the apparent Mode-III toughness, failure is still dominated by tensile mechanisms. The experimental results were further analyzed using improved fracture criteria incorporating critical radius and T-stress effects, enabling more accurate prediction of fracture behavior. These findings provide fundamental mechanical parameters and fracture characterization methods essential for optimizing hydraulic fracturing design in CBM reservoirs.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111597"},"PeriodicalIF":5.3,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227514","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}

引用次数: 0