Engineering Fracture Mechanics最新文献

{"title":"Investigation of the tensile fracture behavior and failure criteria of domestic Zr-2.5Nb alloy under different stress triaxiality conditions","authors":"Xikai Xu ,&nbsp;Zhiyi Wu ,&nbsp;Chen Bao ,&nbsp;Yupeng Cao ,&nbsp;Guannan Zhao","doi":"10.1016/j.engfracmech.2025.110991","DOIUrl":"10.1016/j.engfracmech.2025.110991","url":null,"abstract":"<div><div>The pressure tube (PT) is a critical component of the CANDU (CANada Deuterium Uranium) heavy water reactor, which imposes extremely high safety standards for its materials. This study investigates the tensile fracture behavior of unirradiated Zr-2.5Nb alloy, a domestically produced material for PTs, through a combination of experiments and finite element simulation. The full-range stress–strain relationship for this alloy was established using the finite-element-analysis aided testing (FAT) method. Based on the geometry of the tube, axial and transverse specimens were prepared and subjected to tensile testing. The deformation of the specimens at different stages was monitored, and the stress triaxiality was extracted through finite element simulation. The stress triaxiality distribution laws of the sheet specimens with notch in the direction of width (SNW) and the sheet specimen with a central hole (SCH) were analyzed. Additionally, the parameters of the Johnson-Cook (J-C) failure model were calibrated, and specimens with notches at different angles were designed for verification. The results showed that the Johnson-Cook failure model effectively simulates the tensile deformation and failure behavior of the domestic Zr-2.5Nb alloy. Fracture morphology was examined using scanning electron microscope (SEM), revealing the morphological characteristics of dimples, elongated dimples, and slip marks. The fracture modes of domestically produced Zr-2.5Nb alloy tensile specimens with different notches and orientations were obtained.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"318 ","pages":"Article 110991"},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528792","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":"Microstructural feature-based physics-informed neural network for creep residual life prediction of P91 steel","authors":"Zhi Liu,&nbsp;Zhou Zheng,&nbsp;Peng Zhao,&nbsp;Jian-Guo Gong,&nbsp;Xiao-Cheng Zhang,&nbsp;Fu-Zhen Xuan","doi":"10.1016/j.engfracmech.2025.110989","DOIUrl":"10.1016/j.engfracmech.2025.110989","url":null,"abstract":"<div><div>Creep residual life prediction of materials at elevated temperature is an important topic in the field of structural integrity. Traditional creep residual life prediction methods only consider mechanical parameters (e.g. stress, strain, temperature), while the microstructural features are rarely mentioned, reducing the prediction accuracy. In this work, taking the P91 steel as an example, a microstructural feature-based physics-informed neural network (PINN) for predicting creep residual life was developed by integrating the microstructural characteristics and mechanical parameters. The influence of microstructural features on the prediction results was discussed, and the prediction results of the proposed model and some conventional machine learning methods were compared. The effect of the strain data on creep residual life prediction results was included. The results indicated that the introduction of the microstructural evolution mechanisms (i.e. coarsening of precipitations and subgrain growth) could enhance the creep residual life prediction capacity of the proposed PINN model. The proposed PINN model outperforms the aforementioned traditional machine learning methods in predicting the creep residual life of materials. This model also exhibits excellent prediction performance without incorporating the creep strain data as an input feature, demonstrating the generalization ability and robustness of the proposed model.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110989"},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578369","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 novel framework of neural network for notch fatigue life prediction by integrating self-attention mechanism and implicit physical constraints","authors":"Chenglong Yu ,&nbsp;Qinzheng Yang ,&nbsp;Xiaoan Hu","doi":"10.1016/j.engfracmech.2025.110994","DOIUrl":"10.1016/j.engfracmech.2025.110994","url":null,"abstract":"<div><div>Notch fatigue life prediction is critical aspect of structural integrity analysis. This study proposes a new neural network framework − Attention Physics-Informed Neural Network (AttPINN), integrating self-attention mechanism and implicit physical constraints with neural networks. The self-attention mechanism was integrated to extract hidden pattern in input data by allocating attention to input features automatically. Implicit physical constraints were introduced to capture nonlinear relationships between input data and fatigue life without any prior knowledge. For the training and validation datasets with five types of notches and a life range of 10³-10⁷ cycles, the AttPINN predictions were within ± 2 scatter bands, while results from conventional machine learning model and traditional fatigue life equations were within ± 6 and even ± 15 scatter bands. Moreover, the prediction accuracies satisfy within the ± 3 scatter bands for test dataset. This study highlights that the self-attention mechanism significantly improves the neural network feature extraction and modeling efficiency. Implicit physical constraints enhance the generalization ability of the model, particularly for fatigue data with various notch geometries and materials. Results show that AttPINN significantly improved the prediction accuracy as well as generalization ability, making it a promising tool for notch fatigue evaluation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110994"},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551589","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 debonding mechanisms of Fe-SMA and CFRP bonded joints","authors":"Niels Pichler ,&nbsp;Wandong Wang ,&nbsp;Hossein Heydarinouri ,&nbsp;Elyas Ghafoori","doi":"10.1016/j.engfracmech.2025.110922","DOIUrl":"10.1016/j.engfracmech.2025.110922","url":null,"abstract":"<div><div>Adhesively bonding iron-based shape memory alloy (Fe-SMA) offers a solution to strengthen fatigue-prone metallic structures and prolong their service life. However, adhesive joints being susceptible to debonding failure, static failure was studied in Mode I, Mode II, and mixed-mode conditions, both experimentally and theoretically. The Fe-SMA material behaviour on the debonding mechanism was shown to be influential, reducing the bond capacity compared to carbon fibre reinforced composites (CFRP) strengthening material. So far the study of static joint failure was mainly confined to the debonding under the controlled lap-shear test conditions, a very common test for joint characterization and not on a component scale. The interaction between the structure end the repair was assumed negligible with the focus being on the interaction between the adhesive and adherend. In this manuscript, the static mixed-mode debonding is approached experimentally and theoretically at component scale. The residual tensile strength of a fully separated structural steel or aluminium element repaired with bonded Fe-SMA or CFRP strips of different width is measured. The repair eccentricity induced bending of the structural element is considered. Analytical and finite element modelling of the structural component are validated with the experiment and allow to perform the mode separation. It is shown that the deformation of the structural element affects the mode mixity. When the repair strip stiffness is high relative to the structural components stiffness, the Mode I contribution increased, negatively affecting the component residual strength. However, this effect was shown to be less important for Fe-SMA repair strips due to their material nonlinearity. These bonded repair were thus shown to be more resilient than their CFRP counterpart.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110922"},"PeriodicalIF":4.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551588","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":"Cohesive zone model for the thermomechanical deformation of a high temperature tubular solid oxide electrolysis cell","authors":"Victoria Kurushina ,&nbsp;Anil Prathuru ,&nbsp;Ajith Soman ,&nbsp;Mamdud Hossain ,&nbsp;Qiong Cai ,&nbsp;Bahman Amini Horri ,&nbsp;Nadimul Haque Faisal","doi":"10.1016/j.engfracmech.2025.110987","DOIUrl":"10.1016/j.engfracmech.2025.110987","url":null,"abstract":"<div><div>High-temperature processes for hydrogen production unlock the potential for high energy efficiency combined with a relatively low environmental impact. However, structural integrity should be carefully considered. Solid oxide electrolysis cells (SOEC) employ a range of ceramic and metallic materials capable of withstanding high temperatures, ranging from 500 °C to 1000 °C, while facilitating active electrochemical reactions. The present structural analysis focuses on the challenge of anticipating the formation of debonding cracks at the interfaces of layers (assumed non-porous) within a single SOEC cell with a tubular design and a metal support. This study includes implementation of material properties for ceramic mixtures, model verification, analysis of deformation, stresses, crack formation using the cohesive zone model (CZM) – a method commonly used to simulate the process of crack initiation and propagation. In this pioneering research, several potential areas of debonding have been identified, with the primary concentration occurring around the fixed-end boundaries. Findings reveal a temperature-dependent curvature for the maximum expected total deformations, where a linear growth pattern turns into a random pattern, peaking at 750 °C. Up to eight deformation zones, which could potentially serve as crack initiation locations, are identified near the fixed boundaries, and up to four zones are indicated by deformation contours for the main body of the tubular cell model. The study establishes and reports the evolution of these debonding zones through the high-temperature operating range.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"318 ","pages":"Article 110987"},"PeriodicalIF":4.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534213","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":"On the accuracy of isotropic damage descriptions for complex load paths—Limits quantified by numerical optimization","authors":"K. Feike,&nbsp;P. Kurzeja,&nbsp;J. Mosler,&nbsp;K. Langenfeld","doi":"10.1016/j.engfracmech.2025.110960","DOIUrl":"10.1016/j.engfracmech.2025.110960","url":null,"abstract":"<div><div>The stress triaxiality and the Lode angle parameter are two well established stress invariants for the characterization of damage evolution. At the same time, their limitations are known in principle as they are not sufficient, but remain to be quantified for a full damage description. This work contributes precisely by quantifying these restrictions through numerical optimization in terms of load paths and characteristic damage values. This is a key requirement for an accurate distinction between damage-mitigating and damage-prone scenarios. Such isotropic damage approximations – among others – are utilized in this work for damage predictions in a continuum damage mechanics framework. For that purpose, two well-established damage models are considered and analyzed for different complex load paths. Two models are used in order to avoid model-specific restrictions. For the different load paths, different isotropic damage indicators such as the stress triaxiality and the Lode angle parameter are controlled. The analyses show that well-established concepts such as fracture surfaces depending on the triple stress triaxiality, Lode angle parameter and equivalent plastic strain have to be taken with care, if complex paths are to be investigated. These include, e.g., load paths observed during metal forming applications with varying load directions or multiple stages.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110960"},"PeriodicalIF":4.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551707","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":"Numerical simulation study on hydraulic fracture propagation of multi-cluster fracturing of horizontal well in deep fractured coal seams","authors":"Bo Chen ,&nbsp;Song Li ,&nbsp;Dazhen Tang","doi":"10.1016/j.engfracmech.2025.110983","DOIUrl":"10.1016/j.engfracmech.2025.110983","url":null,"abstract":"<div><div>In recent years, deep coalbed methane has emerged as a focal point for exploration and development, achieving significant success in extraction through large-scale fracturing measures. However, the widespread development of cleat/fracture systems within coal seams has a significant impact on the propagation of hydraulic fractures, and the increasing stress differences caused by deeper burial depths make hydraulic fracturing more challenging. As a result, this study establishes a hydraulic fracturing model for fractured coal seam using a three-dimensional lattice method, and investigates the impact of cleat/ natural fractures, deep geological stress environments, and engineering intervention measures on the propagation of hydraulic fractures. The results indicate that the existence of cleat/ natural fractures in coal seams induces the formation of a complex fracture network system for hydraulic fractures, however the difference in stimulation volume among various perforation clusters increases. When natural fractures near the wellbore are aligned with the direction of hydraulic fractures propagation, the initiation pressure can be significantly lowered. Under different stress regimes, the reverse stress regime exhibits poor stimulation effects, tending to form horizontal fractures, manifesting as “T” and “Z” shaped fractures; the normal stress regime and strike-slip stress regime can form a considerable scale of primary fractures and branch fractures, which is more favorable for the formation of fracture networks. However, an increase in horizontal stress difference promotes hydraulic fractures length growth. When the horizontal stress difference is 12 MPa, hydraulic fractures can develop uniformly and the dynamic distribution of fracturing fluid tends to stabilize. Increasing the fracturing fluid viscosity reduces the reconstruction volume and shortens the fracture length, which is detrimental to the development of long fractures. However, the rapid increase of pumping volume of fracture fluid is most beneficial to the development of fracture length and improves the efficiency of fracturing fluid, making it the most effective for the transformation of fractured coal seams. The results provide a better understanding of the hydraulic fractures propagation mechanism in deep fractured coal seams, offering a reference for the engineering transformation of deep fractured coal seams.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"318 ","pages":"Article 110983"},"PeriodicalIF":4.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527174","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":"Mechanical modes and acoustic emission fractal characteristics of marble failure under true-triaxial loading","authors":"Chuanyu Hu ,&nbsp;Fuding Mei ,&nbsp;Wakeel Hussain ,&nbsp;Zhenhang Xiao","doi":"10.1016/j.engfracmech.2025.110985","DOIUrl":"10.1016/j.engfracmech.2025.110985","url":null,"abstract":"<div><div>Rock dynamic disasters, such as roof caving, wall spalling, and rockbursts, commonly occur in deep underground mines, posing significant safety risks. Although acoustic emission (AE) monitoring technology has greatly advanced the detection and prediction of rock failures, existing approaches primarily emphasize parameter- or waveform-based analyses, which might inadequately capture fractal characteristics and their predictive value. To address these limitations, true triaxial testing was employed in this study to simulate the evolution of failure characteristics in marble rock specimens obtained from a metal mine under complex stress conditions. AE monitoring systems and high-speed cameras were utilized to document the failure processes, and fractal dimension methods were subsequently employed to analyze AE signal characteristics and associated failure modes. The failure process of the rock mass at the free surface was found to progress through distinct stages, including cracking, buckling deformation, and the ejection of rock fragments. The failure mode of the marble specimens was characterized by a combination of shear and tension, with shear failure predominantly observed as the governing mechanism. Furthermore, AE signal patterns exhibited a “quiet period” with minimal counts before catastrophic failure, which served as early warning indicators for potential catastrophic failure. Fractal analyses confirmed that AE amplitude sequences displayed distinct fractal characteristics, with the correlation dimension <em>D</em> sharply decreasing prior to failure, which indicated a transition from chaotic to more ordered states. This study enhances the understanding of rock failure mechanisms under true triaxial stress conditions through the integration of AE monitoring and fractal analysis. The findings thereby provide a significant contribution to safety management practices in deep mining environments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110985"},"PeriodicalIF":4.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551587","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 investigation on the fragmentation behaviour of hard rock with a pre-existing crack under TBM cutter using cohesive zone model","authors":"Wei Gao ,&nbsp;Bin Liu ,&nbsp;Jie Hu ,&nbsp;Y.T. Feng ,&nbsp;Kui Zhang ,&nbsp;Xuejun Zheng","doi":"10.1016/j.engfracmech.2025.110943","DOIUrl":"10.1016/j.engfracmech.2025.110943","url":null,"abstract":"<div><div>This paper presents a numerical investigation into the fragmentation behaviour of pressure-dependent rock with a pre-existing crack under a TBM cutter. To achieve this purpose, an intrinsic cohesive zone model is employed for modelling the initiation, propagation, intersection and closure of cracks. Additionally, the bilinear constitutive law for the cohesive elements is employed to consider the pressure-dependent behaviour of the hard rock with a tensile strength of 6.5 MPa. Firstly, the effectiveness of rock model is validated by comparing the numerical results with the outcomes of the uniaxial compression and triaxial compression experiments. Subsequently, the fragmentation process of the rock under the indention of an elastic cutter of TBM is simulated to numerically investigate the effects of the position and geometry of the pre-existing crack, and the confining pressure on the rock fragmentation. It is found that the depth, length and position of the pre-existing crack, as well as the confining pressure, have a significant effect on the response and fragmentation of rock , including the crack pattern, the crack area, and the contact force from the TBM cutter. Specifically, a deeper and shorter pre-existing crack farther from the contact zone leads to higher contact force and more initial cracks. Furthermore, cracks in the vicinity of the contact zone are typically induced by shear (i.e. mode-II cracks), while the cracks below the pre-existing crack are generated by tension (i.e. mode-I cracks). As the confining pressure increases, the area of the mode-II cracks increases, while the area of the mode-I ones decreases.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"318 ","pages":"Article 110943"},"PeriodicalIF":4.7,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509605","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":"Determination of fracture toughness of concrete based on actual critical crack length: Theoretical model and experimental validation","authors":"Hongwei Wang ,&nbsp;Mengdi Jia ,&nbsp;Xingyu Yang ,&nbsp;Yanjie Wang ,&nbsp;Rena C. Yu ,&nbsp;Zhimin Wu","doi":"10.1016/j.engfracmech.2025.110966","DOIUrl":"10.1016/j.engfracmech.2025.110966","url":null,"abstract":"<div><div>The fracture toughness of concrete is a critical parameter for the evaluation of the stability of cracks and the subsequent safety of structures. However, the parameter is typically underestimated when it is calculated by substituting the effective critical crack length into linear elastic fracture mechanics formulas, thereby impeding the ability to conduct a reasonable assessment of the safety of structures. In light of the above, this study develops a theoretical model for determining the fracture toughness of concrete based on the actual critical crack length. Firstly, the theoretical foundation for the model is elucidated, and governing equations are formulated based on the competition mechanism of the crack propagation resistance and the driving force. These equations can be used to solve the peak load, actual critical crack length, and fracture toughness. Subsequently, to verify the effectiveness of the model, fracture tests of wedge splitting specimens are performed, and the actual critical crack length is captured using the digital image correlation method. The fracture toughness calculated with the proposed model is then compared with the results measured by the authors and collected form the literature. The findings demonstrate that the fracture toughness calculated using the proposed model correlates well with experimental outcomes. Therefore, it can be concluded that the proposed model can be applied to predict the fracture toughness of concrete when the requisite material parameters, including the tensile strength, fracture energy, Young’s modulus, and initial fracture toughness, are provided. This model offers the advantage of considering the actual critical crack length, which would be difficult to measure directly due to the higher demands on the test equipment. It is anticipated that the investigation will facilitate a comprehensive insight into the fracture mechanism of concrete and an accurate estimation of the mechanical performance of concrete structures.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"318 ","pages":"Article 110966"},"PeriodicalIF":4.7,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520515","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}