Engineering Fracture Mechanics最新文献

{"title":"Finite element analyses of rail head cracks: Influence of load characteristics on direction and rate of rolling contact fatigue crack growth","authors":"Mohammad Salahi Nezhad ,&nbsp;Elena Kabo ,&nbsp;Anders Ekberg ,&nbsp;Fredrik Larsson","doi":"10.1016/j.engfracmech.2025.111322","DOIUrl":"10.1016/j.engfracmech.2025.111322","url":null,"abstract":"<div><div>The influence of operational loads on predicted rolling contact fatigue crack growth rates and directions in a rail head is studied. A 3D finite element based numerical framework is adopted featuring a 60E1 rail with an inclined surface-breaking, semi-circular gauge corner crack. The influence of magnitude and position of (normal) contact load, wheel–rail tractive forces, thermal loads, and rail bending under different support conditions is investigated. An accumulative vector crack tip displacement criterion is employed to predict crack growth direction, whereas growth rates are estimated using Paris-type relations. Results are assessed along the crack front for different crack radii. It is found that the crack growth rate is primarily influenced by the contact load magnitude and position. Additional rail bending and thermal loading will somewhat increase predicted growth rates, especially for larger cracks. Crack growth direction under combined loading generally depends on the ratio between the contact load and the bending/thermal load in that poor track support conditions and/or an increased thermal loading (cooling) promote downward growth. Results are useful for rail maintenance planning as illustrated in the study by quantifying the effects of loading conditions on estimated rail life.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111322"},"PeriodicalIF":4.7,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322036","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":"Fiber–matrix interface debonding and transverse cracking in macro fiber composites","authors":"Behrad Koohbor ,&nbsp;Zaynab Hazaveh ,&nbsp;Aurélien Doitrand ,&nbsp;Hugo Girard","doi":"10.1016/j.engfracmech.2025.111345","DOIUrl":"10.1016/j.engfracmech.2025.111345","url":null,"abstract":"<div><div>Fiber–matrix interface debonding is a precursor to transverse matrix cracking at the mesoscopic scale in fiber composites. The mechanisms controlling fiber–matrix interface debonding and subsequent transverse crack formation have been explored primarily by computational methods with limited experimental verification. This study aims to establish an experimental approach for characterizing fiber–matrix interface debonding in model macro fiber specimens that replicate realistic microstructures. The primary goal is to measure strain fields at individual fiber–matrix interfaces using optical digital image correlation (DIC) and link these measurements to the initiation and propagation of transverse cracks. Macro fiber composite specimens are fabricated by embedding dozens of randomly distributed glass macro fibers (1 mm dia.) in an epoxy matrix. These specimens are then subjected to controlled transverse loading, and their local strain fields are monitored and quantified with high-magnification optical DIC. The experimentally obtained kinematic fields are first used to connect global and local deformation responses and to investigate the mechanisms governing matrix cracking between the fibers. The experimental data are then used to set up and validate a modeling framework created based on cohesive zone and phase field formulations to investigate fiber–matrix interface debond initiation and matrix cracking, respectively. The experimental protocols described here provide a practical approach for characterizing deformation and failure at the fiber–matrix interface and tracking their evolution into larger transverse cracks. Complementary simulation studies highlight the significance of boundary conditions and the uncertainty in the fiber–matrix interface fracture properties in realistic and reliable predictions of debonding kinetics and matrix crack formation. The presented approach is transferable to smaller length scales to enable the quantitative assessment of the effects of geometric and morphological factors, such as inter-fiber distance and angle, on transverse crack formation in fiber composites.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111345"},"PeriodicalIF":4.7,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291006","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 the fracture mechanics validity of small scale tests","authors":"Chuanjie Cui ,&nbsp;Livia Cupertino-Malheiros ,&nbsp;Ziyao Xiong ,&nbsp;Emilio Martínez-Pañeda","doi":"10.1016/j.engfracmech.2025.111321","DOIUrl":"10.1016/j.engfracmech.2025.111321","url":null,"abstract":"<div><div>There is growing interest in conducting small-scale tests to gain additional insight into the fracture behaviour of components across a wide range of materials. For example, micro-scale mechanical tests inside of a microscope (<em>in situ</em>) enable direct, high-resolution observation of the interplay between crack growth and microstructural phenomena (e.g., dislocation behaviour or the fracture resistance of a particular interface), and sub-size samples are increasingly used when only a limited amount of material is available. However, to obtain quantitative insight and extract relevant fracture parameters, the sample must be sufficiently large for a <span><math><mi>J</mi></math></span>- (HRR) or a <span><math><mi>K</mi></math></span>-field to exist. We conduct numerical and semi-analytical studies to map the conditions (sample geometry, material) that result in a valid, quantitative fracture experiment. Specifically, for a wide range of material properties, crack lengths and sample dimensions, we establish the maximum value of the <span><math><mi>J</mi></math></span>-integral where an HRR field ceases to exist (i.e., the maximum <span><math><mi>J</mi></math></span> value at which fracture must occur for the test to be valid, <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>max</mi></mrow></msub></math></span>). Maps are generated to establish the maximum valid <span><math><mi>J</mi></math></span> value (<span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>max</mi></mrow></msub></math></span>) as a function of yield strength, strain hardening and minimum sample size. These maps are then used to discuss the existing experimental literature and provide guidance on how to conduct quantitative experiments. Finally, our study is particularised to the analysis of metals that have been embrittled due to hydrogen exposure. The response of relevant materials under hydrogen-containing environments are superimposed on the aforementioned maps, determining the conditions that will enable quantitative insight.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111321"},"PeriodicalIF":4.7,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307874","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 buckling model of fiber-reinforced composite lattice cylinders with the cutout imperfections","authors":"Wenyu Wang ,&nbsp;Jian Xiong","doi":"10.1016/j.engfracmech.2025.111343","DOIUrl":"10.1016/j.engfracmech.2025.111343","url":null,"abstract":"<div><div>The lattice load-bearing cylinder structure, with its exceptional strength-to-weight ratio, holds great promise for application in aerospace engineering. To facilitate structural assembly or the embedding of electronic equipment, various types of cutout structures are often designed on the main load-bearing lattice cylinder. The existing theoretical research on the failure mechanism of lattice cylinders primarily focuses on regular structures without cutouts. When the lattice cylinder with cutouts undergoes buckling, the complexity of the ribs’ shape hinders the establishment of the energy function. An analysis of the mechanical performance of lattice cylinders with localized cutouts is undertaken. Based on the buckling patterns derived from simulation analyses, displacement function assumptions are formulated. A multi-failure analysis model is established for lattice cylinders with cutouts, revealing their underlying failure mechanisms. The validity of the theoretical model is confirmed through simulations and experiments. The study’s findings demonstrate the influence of cross-sectional size and helical angle on the type of failure. A three-dimensional failure mechanism diagram is constructed, bridging the gap in the theory of failure modes for this type of structure. The study delves into the correlation between the maximum critical loads and the dimensions of rectangular and circular beams that traverse the interstitial spaces within lattice cylinders characterized by cutouts. The bearing efficiency is also explored in the study, with the optimal geometric point being identified through mapping structural mass contours and following the optimal bearing efficiency trajectory. This approach broadens the design space and provides a theoretical basis for engineering applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111343"},"PeriodicalIF":4.7,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314084","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":"Tensor-involved peridynamics: A unified framework for isotropic and anisotropic materials","authors":"Hao Tian ,&nbsp;Jinlong Shao ,&nbsp;Chenguang Liu ,&nbsp;Shuo Liu ,&nbsp;Xu Guo","doi":"10.1016/j.engfracmech.2025.111294","DOIUrl":"10.1016/j.engfracmech.2025.111294","url":null,"abstract":"<div><div>In this paper, we present a novel bond-based peridynamic model, termed Tensor-Involved Peridynamics (Ti-PD), which offers a unified framework for simulating both isotropic and anisotropic materials. This model enhances the conventional linear bond-based peridynamics by integrating a fourth-order tensor into the micromodulus function. The tensor components are calibrated to ensure the peridynamic equations converge to the classical continuum elasticity equations as the horizon parameter approaches zero. For isotropic materials with Poisson’s ratios of 1/4 in three dimensions and 1/3 in two dimensions with plane stress condition, the Ti-PD model aligns exactly with traditional bond-based peridynamics. To further expand its applicability, we introduce a damage model specifically designed for isotropic materials, incorporating a novel critical stretch criterion distinct from ordinary state-based peridynamics. The effectiveness of the Ti-PD model in simulating general anisotropic materials is demonstrated through numerical experiments. Additionally, the damage model is validated via simulations of crack propagation in a two-dimensional plate, showcasing superior agreement with experimental data compared to conventional ordinary state-based peridynamics.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111294"},"PeriodicalIF":4.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322040","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":"Molecular dynamics study on the anisotropy of α-quartz fracture properties","authors":"Yin Fangxi,&nbsp;Pan Yongtai,&nbsp;Zhang Chuan,&nbsp;Cao Xingjian,&nbsp;Lu Meiquan,&nbsp;Ye Qianyu","doi":"10.1016/j.engfracmech.2025.111335","DOIUrl":"10.1016/j.engfracmech.2025.111335","url":null,"abstract":"<div><div>The anisotropy of micro fracture properties of α-quartz was systematically studied under tensile loading based on molecular dynamics simulations<strong>.</strong> Tensile loads were applied to α-quartz models with various defects to investigate fracture phenomena, energy evolution, and trends in mechanical properties along the <em>x</em> ([2 1 0]), <em>y</em> ([0 1 0]), and <em>z</em> ([0 0 1]) directions. The results show that loading direction significantly affects fracture mode, mechanical properties, and energy distribution: the <em>x</em> direction exhibits greater elastic energy storage capacity, the <em>y</em> direction has the highest surface energy consumption, and the <em>z</em> direction shows superior fracture strength and structural stability. However, the anisotropy of the fracture process decreases as defect size increases. Prefabricated defects markedly reduce the material’s fracture strength and energy demand. The maximum reductions in fracture strength are 44.87 %, 41.57 %, and 23.12 % for the <em>x</em> ,<em>y</em>, and <em>z</em> directions, respectively, while input energy reductions are 62.98 %, 62.03 %, and 46.00 %. This study systematically elucidates how prefabricated defects and loading directions influence fracture mechanisms and mechanical properties at the atomic scale, highlighting the critical role of anisotropy in energy distribution during fracture. The findings offer theoretical support for energy optimization in mineral crushing and dissociation while providing new insights into the mechanical properties of brittle materials.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111335"},"PeriodicalIF":4.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291192","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":"Crack nucleation mechanism of rock fracture","authors":"Chunlai Wang,&nbsp;Baokun Zhou,&nbsp;Chaoyang Zhu,&nbsp;Changfeng Li,&nbsp;Liang Sun","doi":"10.1016/j.engfracmech.2025.111328","DOIUrl":"10.1016/j.engfracmech.2025.111328","url":null,"abstract":"<div><div>Engineering geological disasters caused by rock damage evolution are closely related to the evolution of crack nucleation. This study developed a damage evolution model of granite under uniaxial loading based on multi-source acoustic emission (AE) data, including AE events time, spatial distribution, and AE energy. The spatial clustering degree of crack evolution was evaluated by visualizing the three-dimensional (3D) AE events and integrating them with the 3D Ripley’s K function. A 3D automatic reconstruction algorithm for crack nucleation bodies was developed, combining the DBSCAN clustering algorithm and Alpha Complex Shape. This approach allows comprehensive quantification of the morphology, number, and volume of crack nucleation bodies, representing an improvement over most existing methods. The crack nucleation growth factor (<em>CNGF</em>), defined by the ratio of crack nucleation body volume to quantity, was introduced to investigate the progressive damage process in rocks further. This helps enhance the understanding of the crack nucleation and damage mechanisms involved in rock crack propagation. It provides valuable insights for both the inversion and prevention of rock-related geological hazards.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111328"},"PeriodicalIF":4.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271966","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":"Accurate fractographic strength estimates in single-crystal silicon via neural network approach","authors":"Lingyue Ma ,&nbsp;Roberto Dugnani","doi":"10.1016/j.engfracmech.2025.111342","DOIUrl":"10.1016/j.engfracmech.2025.111342","url":null,"abstract":"<div><div>Unstable cracks in single-crystal silicon generate smooth fracture surfaces at low crack velocity while forming rough surface features when deflecting onto more energy-favorable cleavage planes at higher propagating speeds. In this study, the surface features induced by cracks propagating on the (110) plane due to a flexural stress field were studied. An iteration approach was used to predict the locations where the crack tip branched onto the {111} plane. The numerical scheme successfully predicted the deflection boundaries for specimens within a broad range of strengths. Characteristic fractographic dimensions discernable on the fracture surfaces produced by 3-point bending were first defined and then utilized to train a neural network model. The proposed model significantly improved the strength estimations in single-crystal silicon compared to traditional fractographic methods. Notably, unlike traditional fractography, the neural networks model displayed comparable strength prediction accuracy when analyzing asymmetric fractographic fracture surfaces formed in the presence of secondary surface damage or lateral cracks.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111342"},"PeriodicalIF":4.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299025","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":"Influences of bedding properties on the mixed-mode fracture behavior of shale under different dynamic loadings","authors":"Dongyang Wu ,&nbsp;Haijian Su ,&nbsp;Liyuan Yu ,&nbsp;Shentao Geng ,&nbsp;Zizheng Sun ,&nbsp;Tao Zhang ,&nbsp;Wenjie Li","doi":"10.1016/j.engfracmech.2025.111337","DOIUrl":"10.1016/j.engfracmech.2025.111337","url":null,"abstract":"<div><div>Understanding the dynamic mixed fracture behavior of shale is crucial for determining parameters in explosive fracturing. Therefore, a split Hopkinson pressure bar (SHPB) was adopted to conduct dynamic fracture tests on cracked straight-through Brazilian disk (CSTBD) shale under different impact loadings. The results revealed that the effective fracture toughness <em>K</em>_eff of shale increased linearly with the loading rate. The enhancing effect of the loading rate on <em>K</em>_eff increased with the pre-fabricated crack angle, and the effect of loading rate on shale with vertical bedding was greater than that of shale with horizontal bedding. Furthermore, the dissipated energy correlated positively with <em>K</em>_eff. A SHPB simulation system was established on the basis of the coupling between FLAC^3D and PFC^3D. The fracture characteristics of shale samples with different bedding tensile strengths were subsequently investigated. The simulation results indicated that the <em>K</em>_eff of shale with horizontal bedding tended to increase in a power function relationship with the bedding tensile strength, and an increase in pre-fabricated crack angle increased the rate of increase. In contrast, the <em>K</em>_eff of shale with vertical bedding was more significantly influenced by the mixed mode than by the bedding tensile strength. The ratio of kinetic energy to dissipated energy was approximately 15%. The fracture energy increased with increasing bedding tensile strength, and shale with horizontal bedding had a more significant effect on the fracture energy. Finally, the effect of bedding properties on shale crack propagation is discussed.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111337"},"PeriodicalIF":4.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291003","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":"Parameter identification for phase-field modeling of brittle fracture in spruce wood","authors":"Matthieu Noel ,&nbsp;Florent Pled ,&nbsp;Luc Chevalier ,&nbsp;François Wilquin","doi":"10.1016/j.engfracmech.2025.111304","DOIUrl":"10.1016/j.engfracmech.2025.111304","url":null,"abstract":"<div><div>Understanding and predicting fracture mechanisms in complex anisotropic materials, such as spruce wood and other biological materials, is essential for structural applications requiring reliability and durability, particularly in the furniture industry. This paper presents a comprehensive two-step approach to identify the elastic and fracture/damage properties of spruce wood by combining numerical predictions from phase-field fracture simulations with experimental measurements from physical experiments. Uniaxial compression tests were conducted on 18 drilled spruce specimens, with displacement fields and critical crack initiation forces measured experimentally using Digital Image Correlation (DIC) techniques. An <em>ad hoc</em> phase-field model for brittle fracture, adapted to anisotropic elastic materials, was employed to numerically simulate crack initiation and propagation in spruce wood. The transversely isotropic elastic properties of spruce wood are identified using a modified Finite Element Model Updating (FEMU) method that incorporates displacement field and global reaction force measurements obtained in the linear elastic regime. The damage/fracture properties of spruce wood, in particular the critical energy release rate characterizing the fracture toughness, are determined through a classical FEMU-based optimization approach that consists of matching the experimental crack initiation forces identified from DIC residual fields and the numerical critical reaction forces predicted by phase-field simulations. The identified material parameters are consistent with values reported in the literature for spruce wood. Numerical results demonstrate the ability of the phase-field fracture model to accurately capture crack initiation forces and replicate the experimentally observed crack paths in perforated spruce specimens under compression. These findings provide valuable insights into the fracture behavior of wood and highlight the potential of phase-field modeling as a robust tool for characterizing and predicting failure in anisotropic elastic materials.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"325 ","pages":"Article 111304"},"PeriodicalIF":4.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307868","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}