Engineering Fracture Mechanics最新文献

{"title":"Coupling of elastoplastic phase field and micromechanics for fatigue fracture in CNT/metal composites","authors":"Yang Sun ,&nbsp;Qihang Zhou ,&nbsp;Jiarui Wei ,&nbsp;Wei Zhang ,&nbsp;Fan Zhang ,&nbsp;Weipeng Hu","doi":"10.1016/j.engfracmech.2025.111158","DOIUrl":"10.1016/j.engfracmech.2025.111158","url":null,"abstract":"<div><div>In this study, we developed a coupled method of micromechanics and elastoplastic phase field to elucidate the inherent connection between the microscopic characteristics and macroscopic fatigue performances of CNT/metal composites. A micromechanical model is initially established utilizing the mean field homogenization approach to assess the elastoplastic constitutive and fracture properties of CNT/metal composites. Based on this foundation, the phase field cohesive zone method is subsequently extended to the realm of elastoplastic fatigue. The predicted constitutive properties and fatigue life is verified by the tensile and cyclic test results of CNT/metal composites. Moreover, the efficiency and robustness of the presented framework for portraying fatigue crack propagation in CNT/metal composites is demonstrated through three typical cases.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111158"},"PeriodicalIF":4.7,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886737","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":"Prediction reliability improvement on long-term creep life for P91 steel using a hybrid method of artificial neural network and CDM model","authors":"Kai Zhang,&nbsp;Xinbao Liu,&nbsp;Lin Zhu","doi":"10.1016/j.engfracmech.2025.111172","DOIUrl":"10.1016/j.engfracmech.2025.111172","url":null,"abstract":"<div><div>In present study, a hybrid method had been proposed to improve the low prediction reliability of long-term creep life for P91 steel using a single conventional model. It combined the continuum damage mechanics (CDM) model with the error-trained back-propagation artificial neural network (BP-ANN) model. Firstly, both the conventional CDM model and the Larson-Miller (L-M) parameter method were employed to predict the long-term creep life. Subsequently, the short-term rupture life data of P91 steel obtained with creep experiments and the related data from the National Institute for Materials Science (NIMS) database and other researchers were utilized to train the hybrid method, respectively. Meanwhile, the extrapolation optimization of the CDM model was carried out with relative errors from the error-trained BP-ANN model.<!--> <!-->Consequently, the long-term creep life of P91 steel was obtained using three different models. The results demonstrated that, in contrast to the L-M parameter method and single CDM model, the present hybrid method with training data lower than 10,000 h exhibits enhanced prediction reliability of the creep life of P91 steel up to 200,000 h, with a relative error of less than 8 %.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"323 ","pages":"Article 111172"},"PeriodicalIF":4.7,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917615","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":"Phase field modeling of damage evolution in nickel-based superalloys","authors":"Jin Wang ,&nbsp;Lan Shang ,&nbsp;Jie Wang","doi":"10.1016/j.engfracmech.2025.111118","DOIUrl":"10.1016/j.engfracmech.2025.111118","url":null,"abstract":"<div><div>The failure of nickel-based superalloys, which is mainly caused by the evolution of damage, has attracted much attention. The damage evolution is highly dependent on the energy release rates and volume fractions of precipitate phase <span><math><mi>γ</mi><mo>'</mo></math></span> in matrix phase <span><math><mi>γ</mi></math></span>. In this work, the influence of precipitate phases with different energy release rates and volume fractions on the damage evolution and the stress–strain curve is investigated by using a continuous damage phase model. It is found that the crack propagation path is almost straight when the energy release rates of the precipitate and matrix phases are close to each other. However, when the energy release rate of the precipitate phase is much larger than that of the matrix phase, the crack propagates along the interface of the two phases. Phase field simulation results indicate that the volume fraction of precipitated phase has a significant impact on the maximum fracture stress. When the volume fraction of precipitate phase increases, the fracture strength of the material is enhanced. Finally, the influence of the pre-crack on the damage evolution is also studied. It is found that the pre-crack decreases the fracture strength of the superalloys significantly. This study not only provides an effective method to predict the damage evolution of nickel based superalloys, but also explains the mechanism of the influence of precipitation and pre-crack on the failure process.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111118"},"PeriodicalIF":4.7,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881795","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":"Engineering definition of small scale yielding condition using imaginary crack tip opening displacement: A practical approach of elastic-plastic fracture mechanics","authors":"Taeseul Park ,&nbsp;Toshiyuki Ishina ,&nbsp;Tatsujiro Miyazaki ,&nbsp;Shigeru Hamada ,&nbsp;Hiroshi Noguchi","doi":"10.1016/j.engfracmech.2025.111137","DOIUrl":"10.1016/j.engfracmech.2025.111137","url":null,"abstract":"<div><div>This study integrates Linear Elastic Fracture Mechanics (LEFM) parameters into Elastic-Plastic Fracture Mechanics (EPFM), employing Imaginary Crack Tip Opening Displacement (I-CTOD) as a unifying metric. Generalized non-dimensional parameters based on I-CTOD enable unified analysis across small-scale yielding (SSY) and large-scale yielding (LSY) domains. Elastic-plastic finite element simulations validate these parameters, evaluating crack length effects on the critical stress intensity factor (<em>K</em>_C) and establishing a theoretical basis for SSY. The proposed SSY condition is compared with empirical formulae, highlighting limitations and refining LSY guidelines. The I-CTOD enhances crack resistance characterization, expanding LEFM’s applicability to diverse fracture mechanics scenarios.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111137"},"PeriodicalIF":4.7,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the mechanism of LF-DAS fiber-optic strain rate evolution and automatic interpretation method for multivariate monitoring wells","authors":"Yalong Hao,&nbsp;Mian Chen,&nbsp;Su Wang","doi":"10.1016/j.engfracmech.2025.111178","DOIUrl":"10.1016/j.engfracmech.2025.111178","url":null,"abstract":"<div><div>Low Frequency Distributed Acoustic Sensing (LF-DAS) data has gradually demonstrated its unique value in hydraulic fracture monitoring. This is due to its ability to reflect the small deformation of rock caused by the propagation of underground fractures during the fracturing process. Furthermore, it serves as a conduit between mechanics and optics. By analyzing the fiber optic strain rate data, the relevant situation of fracture propagation can be obtained, which can provide valuable information for field engineers to adjust the parameters of the fracturing design. However, the existing monitoring results in the field show that the fiber strain rate evolution characteristics are complex and diverse, and the fiber strain rate characteristics vary greatly under different monitoring well types, which poses great challenges to fiber optic interpretation work. Given the inadequacy of systematic analysis of fiber optic strain rate characteristics in existing fiber optic interpretation studies, this paper initially develops a forward LF-DAS fiber optic strain rate model using the finite element method to calculate fiber optic strain rate signals during a single-fracture propagation process. The model is validated by comparison with both the traditional Khristianovich-Geertsma-de Klerk (KGD) model and field LF-DAS data, demonstrating high consistency and confirming its reliability. Furthermore, the evolution of fiber optic strain rate induced by hydraulic fracture propagation is examined under horizontal, vertical, and inclined monitoring well conditions, ultimately identifying eight characteristic patterns of strain rate evolution. We also analyze the effects of parameters such as height difference, monitoring distance, and well inclination on strain rate evolution. Finally, using the LF-DAS strain rate dataset generated by the forward strain rate model, a lightweight CNN model is developed for the automatic identification of fiber optic strain rate evolution patterns, achieving high recognition accuracy on the validation set and demonstrating potential for field application. The fiber optic strain rate evolution characteristics obtained in this study under the multivariate monitoring wells can provide theoretical guidance for on-site fracture monitoring, assist real-time fracturing method adjustment, and have certain reference value for on-site fiber-optic monitoring well placement. In addition, the proposed CNN-based strain rate waterfall plot identification method has certain inspiration for the future intelligent construction of the fracturing site.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111178"},"PeriodicalIF":4.7,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877248","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 thermodynamic consistent phase field fracture model for micropolar medium considering tension–torsion coupling effect","authors":"Hongjun Yu ,&nbsp;Canjie Huang ,&nbsp;Shuai Zhu ,&nbsp;Yaode Yin ,&nbsp;Yingbin Zhang ,&nbsp;Jianshan Wang","doi":"10.1016/j.engfracmech.2025.111170","DOIUrl":"10.1016/j.engfracmech.2025.111170","url":null,"abstract":"<div><div>Materials containing microporous structures or helical inclusions can be homogenized as the micropolar media and usually display a tension–torsion coupling (TTC) mechanical behaviors, resulting in crack deflection phenomena under pure tensile test. The phase field method has increasingly attracted scholars’ interests because of its versality and concision for simulating the fracture failure process. The pre-existing phase field methods for isotropic micropolar materials cannot predict the observation of tension-induced crack deflection behaviors. This paper proposes a new phase field model through introducing a TTC coefficient to character the coupling between the tensile/compressed and shear deformation. Subsequently, the theoretical analysis shows that as the magnitude of TTC coefficient increases, the elastic modulus and ultimate load of micropolar materials decrease. The phase field simulations show that a crack deflection angle increases with the magnitude of TTC coefficient increasing in a micropolar specimen under pure tension and pure shear tests. The TTC coefficient has significant impact on the crack growth pattern and the stiffness compared with the ultimate load. Finally, the present phase field model provides good predictive results of crack deflections in micropolar materials including a limpet tooth under uniaxial tensile test, a human compact bone under mixed-mode test and a L-shaped concrete plate under mixed-mode load.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111170"},"PeriodicalIF":4.7,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899888","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":"Modeling of post-excavation mixed-mode fracture propagation in fluid-saturated porous rock subjected to overburden load","authors":"Swapnil Kar ,&nbsp;Abhijit Chaudhuri ,&nbsp;Vidya Bhushan Maji","doi":"10.1016/j.engfracmech.2025.111125","DOIUrl":"10.1016/j.engfracmech.2025.111125","url":null,"abstract":"<div><div>The present study demonstrates the efficacy of employing a mixed-mode phase field method to comprehensively depict the fracture/crack propagation in mining and excavation environments. When a relatively weak rock formation with pre-existing natural fractures is under compressive overburden load, the stress change due to excavation may instigate Mode I and Mode II types of fracturing by tensile and shear failure, respectively. For fluid-saturated fractures and rock matrix systems, the pore pressure evolution associated with the excavation also gradually alters the effective compressive stress and thus the fracture propagation. To numerically model the fracture propagation, the equations of geomechanics and mixed-mode phase field for fracture mechanics are solved using finite element method (FEM), while the flow equation is solved using finite volume method (FVM). The permeability alteration due to fracture growth is also included. The numerical code for simulating mixed-mode fracturing in solid elastic medium is validated with published results of benchmark problems considering both unstructured and structured grids, showcasing the capability of diffuse crack model and structured grid to simulate mixed-mode fracturing. From the separate simulations of post-excavation fracture propagation using original (only tensile) and mixed-mode phase field methods for fracture networks of different average natural fracture length, it is observed that Mode I type fracturing dominates at the early stage, but at later stages, Mode II type fractures propagate for longer natural fractures. The simulation producing no fracture propagation in the case of dry fractured rock, suggests the involvement of pore pressure diffusion and permeability alteration on fracture propagation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111125"},"PeriodicalIF":4.7,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874593","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":"Solving plane crack problems via enriched holomorphic neural networks","authors":"Matteo Calafà,&nbsp;Henrik Myhre Jensen,&nbsp;Tito Andriollo","doi":"10.1016/j.engfracmech.2025.111133","DOIUrl":"10.1016/j.engfracmech.2025.111133","url":null,"abstract":"<div><div>An efficient and accurate method to solve crack problems in plane linear elasticity via physics-informed neural networks is proposed. The method leverages holomorphic neural networks to learn the complex Kolosov–Muskhelishvili potentials that fulfill the problem boundary conditions. The use of the complex potentials implies that the governing differential equations are satisfied a priori. Therefore, only training points on the domain boundary are needed, leading to superior efficiency compared to analogous approaches based on real-valued networks. To accurately capture the stress singularities at the crack tips, two enrichment strategies are introduced. The first consists in enriching the holomorphic neural networks with the square root term from Williams’ series that provides the correct asymptotic profile near the crack tip. The second leverages Rice’s exact global representation of the solution for a straight crack, which effectively decouples the holomorphic part of the solution from the singular, non-holomorphic terms. The integration of the holomorphic neural network representation with the proposed enrichments significantly enhances the accuracy of the learned solution while maintaining a compact network size and reduced training time. Moreover, both enrichment strategies demonstrate stability and are potentially well-suited for crack detection analyses and simulating crack propagation through the use of transfer learning.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111133"},"PeriodicalIF":4.7,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874595","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":"Fractal analysis of limestone damage under successive impact by shield disc cutters","authors":"Baoping Zou ,&nbsp;Jiahao Yin ,&nbsp;Wengang Zhang ,&nbsp;Xu Long","doi":"10.1016/j.engfracmech.2025.111163","DOIUrl":"10.1016/j.engfracmech.2025.111163","url":null,"abstract":"<div><div>In tunnel constructions, when a shield machine crosses karst areas characterized by soft upper and hard lower layers, the presence of complex fractures and heterogeneities within the limestone significantly affects the tunneling efficiency. The debris produced during shield tunneling contains abundant information that can provide comprehensive feedback on ground conditions and shield machine operational status. Therefore, it is crucial to investigate the microscopic mechanical behavior of limestone under successive impact of shield disc cutters. To address this, a scaled disc cutter model was designed and placed in a dynamic impact mechanical test device for rock. Different successive impact pressures were applied to three groups of limestone to simulate the limestone-breaking process of shield disc cutters under realistic working conditions. Based on fractal mechanics and fracture mechanics theories, a fractal fitting function for crack propagation and failure during successive impact limestone-breaking by the disc cutter was established. The relationship between the fractal dimension of limestone fragmentation, microstructural parameters, and energy absorption was analyzed. The results demonstrated that the fractal dimension of limestone fragmentation predominantly ranged from 1.30 to 1.56, exhibiting clear fractal characteristics. When the fractal dimension approaches 1.5 or its increase reaches 20 %–27 %, it is crucial to promptly implement enhanced support measures to effectively prevent surrounding rock collapse. Moreover, there is a positive correlation between the fractal dimension of limestone fragmentation and the cumulative specific energy absorption. When the cumulative specific energy absorption reaches 60 J·cm⁻³ and the fractal dimension approaches 1.5, it is recommended to reduce the cutterhead pressure and advancement speed, and to conduct preventive maintenance on the cutting tools. These findings provide valuable insights for enhancing the efficiency of shield tunneling operations.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111163"},"PeriodicalIF":4.7,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881814","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":"Numerical simulation of fracture height growth with interference of bedding plane and stiffness contrast in shale reservoirs","authors":"Xiyu Chen ,&nbsp;Manqing Qian ,&nbsp;Yongming Li ,&nbsp;Yitao Huang ,&nbsp;Tai Chang ,&nbsp;Xin Kang","doi":"10.1016/j.engfracmech.2025.111161","DOIUrl":"10.1016/j.engfracmech.2025.111161","url":null,"abstract":"<div><div>Shale formations typically exhibit heterogeneous structures, including bedding planes and interlayers. The mechanical differences between layers, together with bedding planes, significantly affect the vertical propagation of hydraulic fractures. In this study, a finite element model incorporating bedding planes was developed to simulate hydraulic fracture height growth. The model employs global cohesive elements based on a traction–separation law to capture multidirectional fracture propagation. Using the presented model, parametric analyses were conducted to investigate the combined effects of key parameters on fracture growth (either traversing or diversion), including the dip angle, bedding strengths, stress conditions and Young’s modulus contrast between the reservoir with barrier layers. The research reveals how the failure modes of bedding planes and stiffness contrast can affect the vertical fracture extension. The results indicate that varying stress states resulting from changing dip angles can give rise to two distinct failure modes of bedding planes, namely shear-dominated failure and tensile-dominated failure, thus leading to different fracture propagation behaviors. In each regime, only the corresponding strength parameter (shear or tensile strength) influences the fracture height growth. Higher corresponding strength (<em>R</em>_s &gt; 0.30 or <em>R</em>_t &gt; 0.4) increases the tendency of fractures to traverse bedding planes. Furthermore, it was found that the behavior of fracture propagation under stiffness contrast is influenced by the failure mode. When fractures propagate from a hard layer into a soft layer (<em>Y</em>_c &gt; 1) under tensile- or shear-dominated conditions, a softer barrier layer requires a higher corresponding strength to prevent fracture diversion. Conversely, when fractures propagate from a softer layer into a harder layer (<em>Y</em>_c &lt; 1), the stiffness contrast has little impact on fracture behavior under shear-dominated failure of bedding planes; however, under tensile-dominated failure, the stiffness contrast is almost linearly correlated with the tensile strength required for the bedding planes to resist fracture diversion. The study results provide insights that are expected to improve our understanding of fracture height growth mechanisms and contribute to engineering optimization.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"322 ","pages":"Article 111161"},"PeriodicalIF":4.7,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874592","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}