Engineering Fracture Mechanics最新文献

{"title":"Enhancement of fracture toughness and mechanical properties of ultra-high performance concrete with ZnO nanoparticles under mixed-mode loading conditions: a multi-scale numerical investigation","authors":"Arzu Çağlar ,&nbsp;Hakan Çağlar","doi":"10.1016/j.engfracmech.2025.111626","DOIUrl":"10.1016/j.engfracmech.2025.111626","url":null,"abstract":"<div><div>This study is the first to thoroughly examine the effects of zinc oxide (ZnO) nanoparticles (NP) on fracture toughness, particularly in mixed-mode (I-II) conditions. It also pioneers the measurement of the impact of ZnO NP on the mechanical and fracture properties of Ultra-High Performance Concrete (UHPC). In order to simulate the behavior of ZnO nanoparticles in the UHPC matrix while taking into account different fracture modes (Mode I, Mode II, and mixed-mode I-II), the study presents a novel multi-scale finite element (FE) model. In order to improve the durability and performance of cementitious materials under complex loading scenarios, the study determines the ideal dosage of ZnO NP for increasing tensile strength and fracture toughness. The UHPC matrix behavior was simulated by the Concrete Damaged Plasticity (CDP) model, which was calibrated using experimental uniaxial compression and direct tension data. The fracture behavior of the UHPC specimens was examined using the Cracked Straight-Through Brazilian Disc (CSTBD) test configuration with different central crack inclination angles (β). The numerical model’s validity was confirmed against experimental results for β = 0° and β = 45°. A subsequent parametric study assessed the impact of ZnO NPs volume fraction and crack inclination angle on Mode I, Mode II, and mixed-mode (I-II) fracture toughness. Findings indicate that an optimal 0.4 wt% ZnO NPs addition significantly enhances mixed-mode fracture toughness, particularly at critical inclination angles dominated by combined tensile-shear mechanisms. While the optimal dosage for maximizing compressive strength was 0.6 wt% (yielding a 20.6 % increase), 0.4 wt% ZnO proved optimal for enhancing tensile strength (up to 40 % increase) and fracture toughness. Notably, at 0.4 wt%, the pure shear (Mode II) fracture toughness increased by over 2.1 times. This research highlights the substantial potential of ZnO NPs to improve UHPC mechanical properties and fracture resistance under complex, mixed-mode loading conditions.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111626"},"PeriodicalIF":5.3,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264162","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":"Structural cohesive element for the modelling of delamination in composite laminates without the cohesive zone limit","authors":"Xiaopeng Ai,&nbsp;Boyang Chen,&nbsp;Christos Kassapoglou","doi":"10.1016/j.engfracmech.2025.111586","DOIUrl":"10.1016/j.engfracmech.2025.111586","url":null,"abstract":"<div><div>Delamination is a critical mode of failure that occurs between plies in a composite laminate. The cohesive element, developed based on the cohesive zone model, is widely used for modelling delamination. However, standard cohesive elements suffer from a well-known limit on the mesh density—the element size must be much smaller than the cohesive zone size. This work extends the line of research on <em>structural</em> cohesive elements onto 3D mixed-mode problems. A new triangular Kirchhoff–Love shell element is developed for orthotropic materials to model the plies. A new <em>structural</em> cohesive element, conforming to the shell elements of the plies, is developed to model the interface delamination. The proposed method is verified and validated on the classical benchmark problems of Mode I, Mode II, and mixed-mode delamination of unidirectional laminates, a recent unidirectional benchmark problem with curved delamination front, as well as the single-leg bending problem of a multi-directional laminate, significantly increasing the range and complexity of applicable problems as compared to the previous works. All the results show that the element size in the proposed models can be ten times larger than that in the standard cohesive element models, with more than 90% reduction in CPU time, while retaining prediction accuracy. This would then allow more effective and efficient modelling of delamination in composites without worrying about the cohesive zone limit on the mesh density.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111586"},"PeriodicalIF":5.3,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264160","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":"The finite element framework for nonlocal digital image correlation (NL-DIC) for discontinuous displacement fields","authors":"Tushar Bhandari,&nbsp;Debasis Deb","doi":"10.1016/j.engfracmech.2025.111610","DOIUrl":"10.1016/j.engfracmech.2025.111610","url":null,"abstract":"<div><div>A numerical procedure of finite element (FE) method for nonlocal displacement measurement from digital images is proposed. The method is a two-scale model of displacement measurement, which constitutes the classical FE displacement, and a nonlocal displacement measured from the attenuated relative displacement of the neighboring pixels. The traditional finite element-based digital image correlation (FE-DIC) method suffers from noisy and overestimated displacement fields near singularities, analogous to the Gibbs phenomenon. Due to its selective displacement adjustment, the proposed Nonlocal DIC (NL-DIC), detects the displacement jump with reasonable accuracy and smoothen the noise in the vicinity of discontinuity. The algorithm does not require input regarding the affected region from the discontinuity and works as an automated system. The method’s de-noising property helps to decrease the displacement uncertainty for finer meshes. A robust, three-parameter Discontinuity Resolution Index (DRI) is introduced to assess the metrological performance of DIC algorithms for discontinuous displacement measurement. The proposed framework is validated on three numerical experiments exhibiting discontinuities. Practical guidelines are provided, underscoring its applicability in capturing sharp kinematic features with improved robustness.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111610"},"PeriodicalIF":5.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264097","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":"Quantification of pipe-end restraint effects on J and COD for circumferential through-wall cracked pipes in tension","authors":"Jae-Yoon Kim ,&nbsp;Yun-Jae Kim ,&nbsp;Nam-Su Huh ,&nbsp;Do Jun Shim","doi":"10.1016/j.engfracmech.2025.111588","DOIUrl":"10.1016/j.engfracmech.2025.111588","url":null,"abstract":"<div><div>This paper provides analytical equations to quantify the effect of the pipe-end rotation restraint effect on elastic and elastic–plastic <em>J</em> and COD for circumferential through-wall cracked pipes in axial tension. Analytical equations to relate the bending moment in the cracked section and axial tension are derived using displacement and rotation compatibility equations. It is found that negative (crack-closing) bending moment in the cracked section is generated due to end restraint, which is proportional to axial tension due to internal pressure. The method to calculate <em>J</em> and COD for restrained pipe is proposed using the equivalent combined tension and bending moment without end restraint. The Proposed equations are used to predict bending moments in the cracked section, which are then compared with elastic and elastic–plastic FE results for various parametric conditions (such as the axial tension magnitude, crack location, crack length, strain hardening exponent), showing good agreement. FE <em>J</em> and COD from restrained pipes are also compared with the proposed method, showing good agreement.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111588"},"PeriodicalIF":5.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264098","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":"An implicit ordinary state-based peridynamic framework for quasi-brittle fracture problems","authors":"Dong Yang ,&nbsp;Jiaqi Zhu ,&nbsp;Xiaohua Huang ,&nbsp;Xiaoqiao He ,&nbsp;Yajie Deng","doi":"10.1016/j.engfracmech.2025.111609","DOIUrl":"10.1016/j.engfracmech.2025.111609","url":null,"abstract":"<div><div>To robustly and accurately predict quasi-brittle fracture problems using peridynamics (PD), irrespective of the restriction of Poisson’ ratio, a rigorous implicit ordinary state-based peridynamic (OSBPD) fracture framework is developed in this study. The stiffness matrix of an OSBPD bond is established firstly on the basis of a complex truss cluster, which consists of a standard truss element and two groups of affiliated non-standard truss elements. And the correction factors in the stiffness matrix for the discretized model are also clearly revisited. Then, a nonlocal CZM is implemented in OSBPD to describe quasi-brittle behaviors of PD bonds, which is composed of an effective combined damage initiation criterion and a well-established degradation curve. Finite elements are also coupled with OSBPD to reduce the computational cost. To accurately predict fracture problems with snap-back phenomenon, the tangent stiffness matrix is explicitly derived and also the indirect displacement-controlled Newton-Raphson method is exploited in detail. Finally, the validity and robustness of the proposed model is well demonstrated through several representative quasi-brittle fracture examples including the overflow-induced fracture of the Koyna dam of 103 m height. More importantly, the proposed model shows grid size independence, and it behaves as a better alternative to the extrinsic CZM in terms of both accuracy and capability for complex crack.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111609"},"PeriodicalIF":5.3,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264148","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 mechanism underpinning the evolution of rockburst-collapse compound hazards in a deep-buried drilling and blasting tunnel","authors":"Zhihao Kuang ,&nbsp;Shaojun Li ,&nbsp;Shili Qiu ,&nbsp;Yong Huang ,&nbsp;Shuaipeng Chang","doi":"10.1016/j.engfracmech.2025.111590","DOIUrl":"10.1016/j.engfracmech.2025.111590","url":null,"abstract":"<div><div>Two consecutive rockburst-collapse compound hazards that occurred during the drilling and blasting excavation of a deep-buried tunnel in southwestern China were investigated. A systematic engineering geological survey and on-site monitoring were conducted in the hazard-affected zone and adjacent tunnel sections. Utilizing microseismic (MS) monitoring technology and tunnel seismic prediction (TSP), the macroscopic damage of the compound hazards, the spatio-temporal evolution of MS events, the fracture mechanisms, and the inelastic deformation of the source region were characterized. Numerical simulation methods were further employed to reveal the stress-induced mechanisms of the hazards and the rock mass response. The findings are as follows: (1) Rockburst-collapse compound hazards are more likely to occur in areas with abrupt changes in the rock-mass integrity, where the integrity of rock masses in the hazard zone is significantly lower than that in adjacent sections; (2) MS monitoring reveals that the hazard evolution process exhibits a “long quiet period–short active period” pattern, with a sudden increase in high-energy MS events during the active period serving as a critical precursor to the occurrence of a hazard; (3) In the three days preceding the hazard, the inelastic deformation in the source region intensified rapidly, with significant local stress concentration triggering energy release; (4) The mechanism of MS events is characterized by predominantly tensile fracturing in the evolution period, while alternating shear-tensile fracturing occurs during the hazard, with tensile fracturing dominating, revealing the evolutionary path of complex fracture modes; (5) Numerical calculations indicate that zones with significant differences in the integrity of rock masses, the intersection of structural surfaces, and their intersections with the tunnel profile are sensitive areas of stress concentration, prone to forming local high-energy release zones, thereby inducing compound hazards. This study systematically analyzed the mechanisms underpinning the formation of frequent rockburst-collapse compound hazards in deep-buried tunnels, and proposed dynamic excavation adjustment and hazard warning strategies based on MS characteristics and geological conditions. The results offer theoretical support and practical reference for the identification and prevention of similar hazards in engineering practice.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111590"},"PeriodicalIF":5.3,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264094","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":"Differences in fragment size distribution between air-coupling blasting and water-coupling blasting and their formation mechanism","authors":"Jianhua Yang ,&nbsp;Yun Xia ,&nbsp;Zhiwei Ye ,&nbsp;Chi Yao ,&nbsp;Xiaobo Zhang ,&nbsp;Yongli Ma","doi":"10.1016/j.engfracmech.2025.111591","DOIUrl":"10.1016/j.engfracmech.2025.111591","url":null,"abstract":"<div><div>Through using integrated theoretical analysis and numerical simulation, this study addresses the differences in fragment size distribution (FSD) between air-coupling blasting (ACB) and water-coupling blasting (WCB) and reveals their formation mechanism. Firstly, the borehole wall blast load, the stress field of the rock near the borehole, and the extent of the rock failure zones were theoretically calculated. FSD differences between the blasting methods were qualitatively analyzed. Then, a three-hole blasting model was used to simulate blast-induced rock damage under both blasting methods. Based on this, image recognition was used to quantify FSD data, revealing quantitative differences in FSD between the blasting methods. By combining the rock-breaking process with the rock fracture characteristics, a novel failure zone division method was developed to investigate the formation mechanism of the differences. The results show that the fragment size in the two blasting methods follows the Rosin-Rammler distribution. Under identical decoupling coefficients, WCB exhibits a smaller characteristic size parameter <em>x</em>_c yet a higher uniformity index <em>n</em> compared to ACB. With increasing decoupling coefficient, <em>x</em>_c increases linearly while <em>n</em> decreases linearly in both ACB and WCB. Corresponding formulas for <em>x</em>_c and <em>n</em> were established, respectively. In addition, with increasing decoupling coefficient, the difference in overall fragment size between the two methods increases, while the difference in the inhomogeneity of the rock fragments remains stable. The above differences are mainly caused by the different blast loads, which result in different rock fracture patterns and degrees of rock fragmentation in the fracture zone around the borehole, the reflected tensile zone around the free surface, and the superposition zone of compression waves and tension waves. ACB generates fine fragments near boreholes and the free surface in front of the center position of adjacent boreholes, whereas WCB primarily generates them near free surfaces. The formation of boulders in both blasting methods is primarily caused by insufficient rock fragmentation within the fracture zone around the borehole and the superposition zone of compression waves and tension waves.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111591"},"PeriodicalIF":5.3,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264096","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":"Size effect in the J–R curves for the nonlinear shear failure of woven composites","authors":"John Park,&nbsp;Malik John,&nbsp;Kedar Kirane","doi":"10.1016/j.engfracmech.2025.111583","DOIUrl":"10.1016/j.engfracmech.2025.111583","url":null,"abstract":"<div><div>The objective of this study is to investigate the specimen size dependence in the nonlinear shear failure of woven composites. The selected test geometry involves the recently developed modified lap shear test, particularly suited for the characterization of the in-plane shear failure of specimens of multiple sizes. The test involves uniaxial compression of a double-cracked S-shaped specimen, resulting in a predominantly shear induced failure in the specimen ligament. An epoxy/carbon twill woven composite was used to fabricate geometrically scaled specimens of three different sizes. The modified lap shear test on these specimens resulted in a geometrically similar shear failure of all specimens. The behavior was observed to be pseudoductile with a marked nonlinearity and a prolonged post-yield hardening response, followed by specimen self-contact and friction, terminating the test. The propagation of the failure was characterized using the J–R curve approach, generated via J-integral and compliance calibration approach. The calculated J–R curves are found to exhibit a strong dependence on specimen size, with a smaller size exhibiting a smaller toughness for a given effective crack extension. An approximate framework to infer a size-independent J–R curve is proposed, which is verified via cohesive crack simulations and validated via Iosipescu shear failure experiments. These findings emphasize the importance of accounting for this size effect in the J–R curve in designs and numerical models for composite structures subjected to intralaminar shear failure.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111583"},"PeriodicalIF":5.3,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264163","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":"On distribution softening in the yielding of porous materials","authors":"A. Cruzado,&nbsp;A.A. Benzerga","doi":"10.1016/j.engfracmech.2025.111607","DOIUrl":"10.1016/j.engfracmech.2025.111607","url":null,"abstract":"<div><div>The effect of void distribution on yielding is investigated using periodic single-void tetragonal unit cells subjected to symmetric and asymmetric loading conditions. The behavior is compared to that of reference, cubic lattice and random dispersions across porosity levels spanning two orders of magnitude. Small-strain FFT-based simulations are performed using three-dimensional periodic cells with equiaxed voids embedded in an elastic–perfectly plastic matrix. Emphasis is placed on a regime termed unhomogeneous yielding, where deformation localizes into “layered” bands or columnar regions the orientation of which depends on void distribution as well as on the loading. A key feature is the percolation of nondeforming regions within the cell. It is found that elongated tetragonal distributions consistently exhibit a softer response compared to both cubic and random distributions. On the other hand, flat cells are found to alter the mode of percolation. The extent of the apparent first-order effect of void distribution on yielding is analyzed in terms of the concept of band porosity.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111607"},"PeriodicalIF":5.3,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264180","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 the 3D-GMTSN criterion with XFEM to simulate the spatial propagation trajectory of hydraulic fractures interacting with natural fractures","authors":"Yihao Zhang ,&nbsp;Yang Ju","doi":"10.1016/j.engfracmech.2025.111605","DOIUrl":"10.1016/j.engfracmech.2025.111605","url":null,"abstract":"<div><div>The accurate prediction of the spatial propagation trajectory of hydraulic fractures (HFs) that interact with natural fractures (NFs) remains a fundamental challenge in hydraulic fracturing engineering. A notable challenge arises from the formation of complex three-dimensional (3D) fracture networks at the intersections of HFs and NFs, and precise 3D fracture criteria and effective simulation techniques are lacking. In research conducted previously, the 3D-generalized maximum tangential strain (3D-GMTSN) criterion was developed to accurately predict both the direction and onset of 3D fracture initiation. In this study, the 3D-GMTSN criterion was first systematically integrated with the extended finite element method (XFEM) to simulate the spatial propagation trajectory of 3D fractures. To overcome numerical challenges associated with 3D fracture intersections, a redundant enrichment node removal technique to mitigate stiffness matrix singularity, and a coupled element-by-element approach with the conjugate gradient method that eliminates explicit global stiffness matrix assembly. This framework was further enhanced using OpenMP-based parallelization, achieving substantial computational efficiency gains for large-scale engineering simulations. Finally, the spatial propagation trajectory of the interaction between HFs and NFs was successfully simulated. This work establishes an integrated framework combining physics-driven criteria, robust numerical algorithms, and high-performance parallel computing. The numerical model used in this study can effectively simulate complex fracture interactions, thereby overcoming a notable challenge in hydraulic fracturing engineering.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"329 ","pages":"Article 111605"},"PeriodicalIF":5.3,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264100","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}