Theoretical and Applied Fracture Mechanics最新文献

{"title":"Mixed-mode crack growth simulation in rock-like materials with the smoothing gradient-enhanced damage model associated with a novel equivalent strain","authors":"Chanh Dinh Vuong ,&nbsp;Thanh-Trung Vo ,&nbsp;Tinh Quoc Bui","doi":"10.1016/j.tafmec.2024.104768","DOIUrl":"10.1016/j.tafmec.2024.104768","url":null,"abstract":"<div><div>Accurately modeling mixed-mode crack propagation in rock-like materials remains challenging due to the complexity of the deformation states and mechanism of fracture throughout the loading history. The objective of this paper is to analyze the damage process in rock-like materials using an enhanced smeared damage model. The mixed-mode failure in rocks is captured using our recently developed smoothing gradient damage model in conjunction with a novel equivalent strain formulation, which is developed by combining both the bi-energy norm equivalent strain and the four-parameter equivalent strain. To validate the accuracy of the developed method, several commonly reported rock fracture examples are considered in which complex crack paths and responses are reproduced and compared with the available experimental data.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"135 ","pages":"Article 104768"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098665","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 direct crack sizing approach from DIC strain analyses under elasto-plastic and dynamic conditions","authors":"Cheng Chen,&nbsp;Xudong Qian","doi":"10.1016/j.tafmec.2025.104861","DOIUrl":"10.1016/j.tafmec.2025.104861","url":null,"abstract":"<div><div>This paper proposes a novel approach to quantify the crack size from strain fields measured from digital image correlation (DIC), by extrapolating the positions at peak strain or peak strain increments identified along paths parallel to the crack plane. The proposed approach does not require data in the immediate vicinity of the crack tip, where DIC measurement is usually less accurate. This study utilizes the modified boundary layer model to demonstrate the strain pattern underpinning the crack size from HRR theory and the single edge notched bend model to verify the crack sizing accuracy from the strain fields. The experimental study further validates the proposed method in plane-sided and side-grooved specimens and evaluates the plastic wake effects on the crack-sizing accuracy for propagating cracks under elasto-plastic conditions. The proposed method identifies the crack tip location directly without measuring the elastic compliance, which enables fast and convenient crack sizing under challenging conditions such as the impact tests. This study demonstrates enhanced fracture resistance of the S550 material under increasing loading rates using the proposed crack sizing method.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104861"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143197088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of failure characteristics and constitutive model development for sandstone with different ligament angles under biaxial loading based on infrared radiation","authors":"Longfei Chang ,&nbsp;Lu Chen ,&nbsp;Mingyuan Zhang ,&nbsp;Bo Hu ,&nbsp;Weichen Li ,&nbsp;Dejian Li ,&nbsp;Yingjun Li","doi":"10.1016/j.tafmec.2025.104856","DOIUrl":"10.1016/j.tafmec.2025.104856","url":null,"abstract":"<div><div>The instability and failure mechanisms of engineering rock masses are significantly influenced by fissures, increasing their uncertainty. Under the action of a lateral constraint load, the bearing characteristics and deformation behavior of rock masses become more complex. To investigate the impact of the ligament angle on failure mechanisms and provide precursor information for rock instability, this study conducted biaxial compression experiments on pre-cracked sandstones with varying ligament angles. Infrared thermal imaging (ITI), acoustic emission (AE), and digital image correlation (DIC) were employed. The results indicate the following: First, pre-cracked sandstone samples with different ligament angles exhibited variations in elastic modulus and strength. However, under lateral load constraints, these variations were minimal, and the failure mode demonstrated ductile characteristics. As the ligament angle increases, the crack coalescence mode transitions from the shear crack coalescence mode to the tension-dominated tensile-shear mixed mode. Second, a predictive infrared radiation-based index, the difference in average infrared radiation temperature (<em>DIRT</em>), was proposed to monitor the evolution of rock damage. The rate of change in the <em>DIRT</em> can be divided into three phases: the “steady phase–accelerated growth phase–rapid growth phase,” corresponding to different stages of damage development during rock loading. Finally, a damage variable was defined on the basis of the <em>DIRT</em>, and a damage constitutive model for rock was established. The model’s computational results closely match the experimental curves, validating the rationality of the defined damage variable.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104856"},"PeriodicalIF":5.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic fracture simulation of flawed rocks under varying loading rates by the rate-dependent SW-DVIB model combined with EPM","authors":"Yuezong Yang ,&nbsp;Yujie Wang","doi":"10.1016/j.tafmec.2025.104857","DOIUrl":"10.1016/j.tafmec.2025.104857","url":null,"abstract":"<div><div>The mechanical characteristics of rocks are substantially influenced by their strain rate, and the intricacy of rock dynamic failure is compounded by the presence of flaws within the rock structure. In this study, a rate-dependent Stillinger-Weber (SW) potential based discretized virtual internal bond (DVIB) model is proposed and integrated with the element partition method (EPM) to simulate the dynamic fracture of flawed rocks under varying loading rates. The rate-dependent SW potential, which is an improvement of the conventional trilinear damage potential, is produced by altering material properties to account for strain rate effects. A series of Split Hopkinson Pressure Bar (SHPB) experiments were simulated on various flawed specimens, including single-flawed, parallel-flawed and cross-flawed specimens, to validate the accuracy of our model for simulating rock dynamic fracture. The simulated findings demonstrate that all specimens’ dynamic strengths increase as the strain rate increases. For single-flawed and parallel-flawed specimens, the dynamic strength initially decreases and then increases as the flaw angle increases. Asymmetric cross-flawed specimens exhibit higher dynamic strengths compared to their symmetric counterparts. An increase in strain rate can exacerbate the dynamic failure characteristics and failure degree of different kinds of flawed specimens. The single-flawed and parallel-flawed specimens’ tensile failure characteristics deteriorate and their shear failure characteristics rise with an increase in flaw angle. The failure pattern of parallel-flawed specimens is more sensitive to changes in flaw angle than to variations in flaw spacing. Under the same strain rate conditions, the failure pattern of asymmetric cross-flawed specimen is more complex than that of symmetric cross-flawed specimen. The comparison between the simulated and experimental results confirms that the developed rate-dependent SW-DVIB model combined with EPM proves to be an effective tool for simulating the dynamic fracture behavior of flawed rocks under varying loading rates.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104857"},"PeriodicalIF":5.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue behaviors of pre-flawed orthoclase granite under monotonic and multi-level cyclic loadings","authors":"Yue Li ,&nbsp;Sheng-Qi Yang ,&nbsp;De-An Zheng ,&nbsp;Yu Song ,&nbsp;Xiang-Xi Meng ,&nbsp;Ke-Sheng Li","doi":"10.1016/j.tafmec.2025.104858","DOIUrl":"10.1016/j.tafmec.2025.104858","url":null,"abstract":"<div><div>Fissures with various inclination angles are present in engineering rocky slopes, a structural geological product, profoundly influence the long-term stability of rock engineering; whereas, exploration on its macroscopic failure mechanisms and fatigue mechanical characteristics of pre-flawed granite specimens are insufficient. Therefore, this study investigated the fatigue mechanical responses and meso-macro fracture mechanisms of pre-flawed granites with different pre-flaw spaces under monotonic and multilevel fatigue loadings using the CT imaging and three-dimensional crack reconstruction technology. Results showed that the strength of granites with short, medium and long flaw-spacing and intact specimens increased sequentially. Under multilevel fatigue loading, the stiffness of pre-flawed granite produced a significant hardening and a staged increase, similar variation pattern was also reflected by the input energy density and elastic strain energy. Meanwhile, In the last fatigue stage, the damage factor of granites appeared a ‘<span><math><mrow><mfenced><mrow><munder><mrow><mspace></mspace><mspace></mspace><mspace></mspace></mrow><mo>̲</mo></munder><mspace></mspace></mrow></mfenced></mrow></math></span>’ − shaped upward trend, the damage deterioration rate of the specimens was the fastest during this stage. Finally, the type of pre-flaw spacing controlled the macroscopic failure patterns and crack network of granite. The non-uniform stresses at tips of pre-flawed flaws were responsible for inhibiting cracks development. The smaller the non-uniform stress was, crack network had the more possible properties to develop. Consequently, the crack network was more developed in granite with longer pre-flaw spacing.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104858"},"PeriodicalIF":5.0,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130761","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":"Mixed-mode I/II fracture investigation of 3D printed poly ether ether ketone (PEEK)","authors":"Gaurav Sharma ,&nbsp;Amol Vuppuluri ,&nbsp;Anirudh Udupa ,&nbsp;Kurra Suresh","doi":"10.1016/j.tafmec.2025.104854","DOIUrl":"10.1016/j.tafmec.2025.104854","url":null,"abstract":"<div><div>3D printed PEEK components are now routinely utilized in dental, automotive, and aerospace sectors as PEEK can potentially replace metals. However, a correct evaluation of the fracture behavior and structural integrity especially under mixed-mode loading situations is highly desired to avail the benefits of 3D printed PEEK structures fully. In the present study, the mixed-mode I/II fracture response of additively manufactured PEEK thin sheets is explored using the essential work of fracture (EWF) approach. The length of the actual fracture process zone is incorporated into the mathematical formulation of the EWF approach for the first time to assess the mixed-mode fracture phenomena accurately. The<!--> <!-->mode-mixity<!--> <!-->of loading is introduced by varying the orientations of the pre-cracks in 3D printed PEEK specimens. We found that both the essential work of fracture w_e and the plastic dissipation w_p increased monotonically with the pre-crack angle. This indicates that the mixed-mode fracture toughness is substantially greater than the Mode-I toughness. Furthermore, the tendency of the pre-cracks to deviate from the notch-plane was characterized by ex-situ microscopy. The fractured surfaces of 3D-printed cracked specimens are also investigated to recognize the potential mixed-mode failure mechanisms. The observations and analyses presented in this study provide necessary directives for evaluating the strength and longevity of additively manufactured PEEK components.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104854"},"PeriodicalIF":5.0,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372475","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":"Preface to the special issue of Theoretical and applied fracture mechanics - fatigue crack growth - multiscale modelling and crack path analysis in engineering materials","authors":"Stanislav Seitl (Guest editor) ,&nbsp;Jiří Man (Guest editor) ,&nbsp;Michal Jambor (Guest editor)","doi":"10.1016/j.tafmec.2025.104860","DOIUrl":"10.1016/j.tafmec.2025.104860","url":null,"abstract":"","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104860"},"PeriodicalIF":5.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430054","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":"Anisotropic phase-field model for fracture analysis of thin fiber-reinforced composites","authors":"Hao-Jie Wang,&nbsp;Jing-Fen Chen","doi":"10.1016/j.tafmec.2025.104855","DOIUrl":"10.1016/j.tafmec.2025.104855","url":null,"abstract":"<div><div>In this work, an anisotropic phase-field model (PFM) which is able to combine various damage initiation criteria is developed for the fracture analysis of thin fiber-reinforced composites. In order to prevent the unrealistic contribution of the fiber/matrix driving force to the failure of the matrix/fiber, two activation parameters are introduced in the crack driving force to determine the damage initiations of both the fiber and matrix, respectively. To improve computational efficiency and alleviate convergence difficulties, explicit time integration rules are adopted to solve the nonlinear governing equations. The present model is implemented in the finite element procedure ABAQUS through the user-defined element subroutine VUEL, and the efficiency of the present model is verified by the fracture analysis of unidirectional composite laminates. The predicted results agree well with the experimental and other numerical results reported in the literature. In addition, the necessity of separately introducing two activation parameters for fiber and matrix failure in the present phase-field model is investigated.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104855"},"PeriodicalIF":5.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348897","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":"Differential evolution of the anisotropic fracture characteristics of laminated rock under monotonic and fatigue loading","authors":"Cunbao Li,&nbsp;Yanshao Deng,&nbsp;Heping Xie,&nbsp;Peng Chu,&nbsp;Yifei Liu","doi":"10.1016/j.tafmec.2025.104859","DOIUrl":"10.1016/j.tafmec.2025.104859","url":null,"abstract":"<div><div>To study the difference anisotropic fracture evolution of laminated rock between monotonic loading and fatigue loading, this study conducts three-point bending and real-time digital image correlation (DIC) monitoring tests on shale with 7 different bedding orientations under these two different loading paths. DIC is used to analyze the anisotropic horizontal and shear strain fields, crack dominant parameters (CDP), crack tip opening displacement (CTOP), and fracture process zone (FPZ) characteristics. The results indicate that the peak load is generally lower under fatigue loading than under monotonic loading, and the difference becomes more pronounced as the bedding angle increases. Under fatigue loading, the load–displacement curve has four stages: the elastic, stable microcrack evolution, unstable microcrack evolution, and failure stages. Three stages are observed under monotonic loading without obvious unstable microcrack evolution stages. The CDP values are smaller under fatigue loading than under monotonic loading, indicating that shear stress has a more pronounced effect on crack evolution under fatigue loading, and the shale samples are more prone to tensile-shear failure. The CTOD shows anisotropic characteristics influenced by the bedding angle. The variance of CTOD values measured for seven bedding angle specimens under monotonic load is 2.68, while it is 2.94 under fatigue load. The average length and width of the FPZ under fatigue loading are 1.2 to 1.3 times greater than those under monotonic loading, resulting in a larger damage zone. Under fatigue loading, the bedding structure accelerates the formation of microcracks and the anisotropy of shale mechanical behavior is more pronounced. This is because damage accumulates gradually with increasing load during monotonic loading, while repeated loading and unloading in fatigue loading results in significantly more cracks and crack expansion propagation.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104859"},"PeriodicalIF":5.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130760","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":"Investigating the mixed-mode creep crack growth behavior of GH4169 superalloy: Experimental and numerical approaches","authors":"Xin Huang ,&nbsp;Hongyu Qi ,&nbsp;Shaolin Li ,&nbsp;Qikun Xie ,&nbsp;Xiaoguang Yang ,&nbsp;Duoqi Shi","doi":"10.1016/j.tafmec.2025.104852","DOIUrl":"10.1016/j.tafmec.2025.104852","url":null,"abstract":"<div><div>Time-dependent fracture mechanics primarily addresses creep crack growth (CCG) in creep-ductile materials. However, certain superalloys exhibit creep-brittle behavior, where CCG rates are governed by <em>K</em>. In this study, the mode I and I/II mixed mode CCG behavior of the superalloy GH4169 at 550 °C were investigated using experimental and numerical methods. Scanning electron microscope observations showed that intergranular fracture dominated the initial and stable crack growth stages. Finite element analysis indicated that the crack tip remained small scale creep and predominantly exhibited mode I behavior once crack growth initiated. For various loading angles, the d<em>a</em>/d<em>t</em>-<em>K</em>_I curves aligned along a single line. The crack growth angle, predicted by MTS theory, showed good agreement with experimental results. Additionally, FRANC3D software was used to simulate the CCG behavior.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104852"},"PeriodicalIF":5.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143130755","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}