Engineering Fracture Mechanics最新文献

{"title":"Multi-axial fatigue of high-strength concrete: Model-enabled interpretation of punch-through shear test response","authors":"Mario Aguilar,&nbsp;Abedulgader Baktheer,&nbsp;Rostislav Chudoba","doi":"10.1016/j.engfracmech.2024.110532","DOIUrl":"10.1016/j.engfracmech.2024.110532","url":null,"abstract":"<div><div>This paper aims to fill the gap in multi-axial fatigue characterization of concrete by presenting a comprehensive numerical analysis of data from the punch-through shear test (PTST), which allows control over combined shear and compression loads in the tested ligament. To accurately reproduce the degradation process in this multi-axial configuration, a material model must capture two key effects: (i) dissipative behavior at the inter-aggregate level during subcritical pulsating loading and (ii) fatigue-induced tri-axial stress redistribution in the test ligament. The recently published MS1 model by the authors effectively incorporates these features, thereby enabling a deeper interpretation of the experimental data. The former effect is seamlessly integrated into the model using the Lemaitre-type fatigue hypothesis, facilitating the direct derivation of general evolution equations. The latter effect is efficiently represented through the microplane homogenization framework. The model’s predictions for PTST response under monotonic shear loading with varying levels of radial confinement align well with experimental results. Similarly, the simulated fatigue response accurately reproduces the experimentally observed S-N (Wöhler) curves. Further studies demonstrate the model’s ability to predict the effect of fatigue loading sequence. A thermodynamically-based formulation provides an energetic interpretation of this effect, offering a quantitative breakdown of energy dissipation attributed to individual dissipative mechanisms over the lifetime of the material. The studies show that damage-induced dissipation remains almost constant regardless of different fatigue loading histories.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"311 ","pages":"Article 110532"},"PeriodicalIF":4.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529421","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":"Identification of Novel Biomarkers Using Serum and Urinary Proteomics for Early Detection of Hypoxic Ischemic Encephalopathy.","authors":"Sumrati Gurtoo, Chinmaya Narayana Kotimoole, K S Sahana, A B Arun","doi":"10.1007/s12291-023-01143-2","DOIUrl":"10.1007/s12291-023-01143-2","url":null,"abstract":"<p><p>Hypoxic-ischemic encephalopathy (HIE) is a severe birth complication affecting neonates. Around 40-60% of affected neonates die by two years of age or have severe disabilities and neurodevelopmental delays. The early assessments of brain injury using traditional clinical and biochemical indicators do not always align with its severity and recovery. This delays identifying neonates who may benefit from adjuvant therapeutic strategies and monitoring therapy response. Our aim was to identify specific proteins using proteomic approach to predict the severity of neonatal asphyxia so that its outcome can also be prevented. To achieve this goal a case-control study was conducted on 38 neonates, and serum and urine samples were collected within 24 h of life. Clinical findings, biochemical parameters, and outcomes of the neonates were recorded. A tandem mass spectrometry-based quantitative proteomics approach was used to identify proteins in the serum and urine of HIE neonates. Bioinformatics analyses were performed to assess the potential features and competence of the identified differentially expressed proteins. This resulted in identification of 51 differentially expressed proteins which were found common to both serum and urine proteomic data. Some of the promising biomarkers found were APOD, ORM1, SOD1, and FABP1. These proteins were associated with the pathways like Amyloid fiber formation, diseases of programmed cell death, detoxification of reactive oxygen species, and neurodegenerative diseases. This study will pave the way for identifying the biomarkers (proteins) that can screen neonates for brain injury and monitor the disease progression, which may reduce mortality and neurodevelopmental impairment.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s12291-023-01143-2.</p>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"243 1","pages":"506-518"},"PeriodicalIF":1.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11436606/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88485439","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":"Influence mechanism of initial mechanical damage on concrete permeability and tunnel lining leakage","authors":"Chenyang Zhao ,&nbsp;Mingfeng Lei ,&nbsp;Chaojun Jia ,&nbsp;Chaoguang Wu ,&nbsp;Zihan Yang ,&nbsp;Yuanbo Shi","doi":"10.1016/j.engfracmech.2024.110531","DOIUrl":"10.1016/j.engfracmech.2024.110531","url":null,"abstract":"<div><div>The stress state is not effectively considered in existing studies when researching the permeability evolution of concrete with initial mechanical damages, causing ambiguity in the influence mechanism of initial mechanical damage on tunnel lining leakage. This deficiency can lead to significant uncertainty in predicting the probability and evaluating the consequences of tunnel leakage diseases, further affecting the formulation of relevant prevention strategies. Therefore, mechanical damage is induced to concrete specimens by subjecting them to certain stress levels, and triaxial compression seepage tests are subsequently conducted to study the influence of initial mechanical damage on permeability evolution and macrocracks. Furthermore, the relationship between microcrack characteristics and concrete permeability is studied, ultimately revealing the influence mechanism of initial mechanical damage on tunnel lining leakage. Research results indicate that the concrete permeability decreases first, becomes stable, and then continuously increases during testing, and is positively related to changes in horizontal deformation ratio. When the damage-inducing stress reaches 80% of the uniaxial compressive strength (UCS), the impact of initial mechanical damage on concrete permeability increases significantly. The increase in initial mechanical damage can lead to a significant rise in permeability, even when the crack volume is in a compacted state. Additionally, cracks on the surface of the specimen become clearly visible when the test terminates, once the damage-inducing stress reaches 85% UCS. Two factors contribute to the gradual increase in concrete permeability with the rise in initial damage-inducing stress. Firstly, microcracks inside the concrete gradually widen and propagate. Secondly, the microcracks resulting from the initial damage progressively enlarge due to water pressure during the triaxial compression seepage test. Influenced by the blockage of seepage channels, concrete permeability can occasionally decrease during testing. The accidental load induces the gradual propagation of microcracks inside the mechanically damaged concrete. Then, the rebound deformation of concrete after the removal of the accidental load causes the closed microcracks to reopen significantly, leading to an increase in permeability and subsequent tunnel lining water leakage.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110531"},"PeriodicalIF":4.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422619","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":"Mode-I fracture failure mechanism of 3-D braided composites under low-velocity wedge-loaded impact","authors":"Juan Fang,&nbsp;Baozhong Sun,&nbsp;Bohong Gu","doi":"10.1016/j.engfracmech.2024.110533","DOIUrl":"10.1016/j.engfracmech.2024.110533","url":null,"abstract":"<div><div>Mode-I low-velocity impact fracture very often happens during the lifetime service of fiber-reinforced composites. Three-dimensional braided carbon fiber/epoxy composites (3DBC) have higher fracture toughness than laminate, while the Mode-I fracture is also an important behavior. Here we report the Mode-I fracture of 3DBC under low-velocity impact. A single cleavage triangle (SCT) specimen was prepared for the Mode-I impact test. A high-speed camera was used to capture images of the fracture initiation and growth. The inner damages were observed using X-ray microcomputed tomography (Micro-CT). The fracture behaviors were also compared among three braided angles and three impact energies. We found that the crack propagation follows the path of the crimped yarn. The propagation direction changes upon reaching interweaved points. The energy absorption at rupture increases as the braiding angle. A finite element analysis (FEA) model was developed to analyze the internal crack propagation behaviors and failure mechanisms. The fracture mechanisms of 3DBC have been compared between the tests and the FEA results. It was found the braided angle of 45°has a higher impact fracture toughness than the can 10°, 20° and 30° samples.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110533"},"PeriodicalIF":4.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422621","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":"Atomistic analysis of nano He bubble evolution in Al: considering stress triaxiality and Lode parameter effects","authors":"Wei-Dong Wu ,&nbsp;Jian-Li Shao","doi":"10.1016/j.engfracmech.2024.110527","DOIUrl":"10.1016/j.engfracmech.2024.110527","url":null,"abstract":"<div><div>The He bubble is of utmost importance for understanding the dynamics and evaluating the performance of irradiated metals. This work systematically investigates the effect of the stress triaxiality and Lode parameter on the evolution of He bubble in Al via molecular dynamic simulations. Numerical results show that implanting He atoms into the cavity reduces the yield strength but boosts the ductility of the material, with this effect becoming more pronounced as both the stress triaxiality and Lode parameter decrease. One important discovery is the He bubble fragmentation under low stress triaxiality, and the underlying mechanism mediated by dislocation slip and surface diffusion is clearly revealed. Conversely, the He bubble tends to coalesce under high stress triaxiality, and the coalescence strain increases with the increasing He concentration. Additionally, the heuristic applications of coalescence onset criteria for He bubble are explored. The extended Thomason criterion, considering the hardening effect, provides qualitatively acceptable predictions.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110527"},"PeriodicalIF":4.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422624","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":"Experimental study on the macroscopic and mesoscopic mechanical characteristics of deep damaged and fractured rock","authors":"Qingbin Meng ,&nbsp;Xuan Zhang ,&nbsp;Shuailing Zhu ,&nbsp;Hai Pu ,&nbsp;Jiangfeng Liu ,&nbsp;Yanlong Chen ,&nbsp;Jiangyu Wu","doi":"10.1016/j.engfracmech.2024.110529","DOIUrl":"10.1016/j.engfracmech.2024.110529","url":null,"abstract":"<div><div>Most of the rock surrounding deep roadways is in a fractured state; fractured rock has significant rheological properties, and the time-dependent mechanical properties of fractured rock affect excavation construction, support design, and long-term stability of deep roadways. Triaxial compression and mercury intrusion tests are conducted on the bearing characteristics of severely damaged and fractured rock samples, indicating the strength degradation properties of these samples. The evolution of the internal pore structure in damaged and fractured rock samples is analyzed in relation to changes in unloading points (pre-peak stage, peak point, and post-peak stage), leading to the establishment of a quantitative evaluation index for rock damage based on the porosity evolution. Short-term rheological testing is performed on rock samples with varying degrees of damage and fracture, demonstrating the evolution of creep and stress relaxation characteristics. The findings contribute to a deeper theoretical understanding of the post-peak mechanical properties of coal and rock masses, which hold significant theoretical implications and can inform research on long-term stability in underground engineering applications, such as deeply buried roadways, tunnels, and chambers.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110529"},"PeriodicalIF":4.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422622","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 the plastic J integral of ductile material using the XFEM with only Heaviside function and variable-node elements","authors":"Huachao Deng,&nbsp;Bo Yan,&nbsp;Liming Chen,&nbsp;Kaiwen Wu,&nbsp;Hanxu Yang","doi":"10.1016/j.engfracmech.2024.110524","DOIUrl":"10.1016/j.engfracmech.2024.110524","url":null,"abstract":"<div><div>In this paper, the extended finite element method (XFEM) with only Heaviside function is proposed for the elastic–plastic fracture mechanics (EPFM) modeling. The proposed method removes tip enrichment functions depending on the polar coordinates at the crack front, and a step function only determined by the level set function is utilized to track the crack front. To alleviate the volumetric locking phenomena caused by the plastic incompressibility, the B-bar method is incorporated into the three dimensional (3D) XFEM program. Therefore, the fully integration scheme can be chosen to ensure the accuracy when addressing large plastic deformation in EPFM analysis. Additionally, the material tangent stiffness matrix of Ramberg-Osgood constitutive is given, and the local refinement technique using variable-node elements is adopted to reduce the number of elements and nodes for efficient analysis. A Newton-Raphson iterative algorithm is developed to solve the nonlinear algebraic equations caused by material nonlinearity. Several numerical examples including the determination of crack opening displacement, and the fully plastic <em>J</em> integral in the ductile materials are presented to test the performance of the proposed method. Comparisons with the results from the existing methodologies show that the new enrichment scheme can save computational cost and obtain sufficient accuracy even in the case of 3D curved crack.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110524"},"PeriodicalIF":4.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422620","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":"Reactive molecular dynamics of the fracture behavior in geopolymer: Crack angle effect","authors":"Mengxiang Fang ,&nbsp;Tongfang Wang ,&nbsp;Tong Guo ,&nbsp;Pan Shi ,&nbsp;Biao Jiang ,&nbsp;Chao Wang ,&nbsp;Yongming Tu ,&nbsp;Gabriel Sas","doi":"10.1016/j.engfracmech.2024.110521","DOIUrl":"10.1016/j.engfracmech.2024.110521","url":null,"abstract":"<div><div>Reactive molecular dynamics was applied in this study to construct the sodium aluminosilicate hydrate (N-A-S-H) and tensile fracture models with various crack angles. The impact of crack angle on the behavior of N-A-S-H fractures was explored while considering structural mechanical properties and energy evolution. Furthermore, the fracture toughness and brittleness index for various crack angle models were calculated. The findings indicated that the ultimate strength and elastic modulus of the fracture models grew linearly with the increase in crack angle. The fracture toughness value progressively grew while the model’s elastic energy efficiency and new surface energy efficiency decreased simultaneously. The 45° crack model possessed the largest oblique crack development surface in the fracture process due to the coupling effect of tensile and shear stress. Its elastic energy efficiency decreased as well the most, while the new surface energy efficiency increased and the fracture toughness value dropped sharply. It is crucial to place a stronger emphasis on spotting cracks both in the in-service structures or structures being demolished. This ensures optimal performance and safety by enabling more effective adjustments to the direction of external forces and energy input.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"311 ","pages":"Article 110521"},"PeriodicalIF":4.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425300","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 fatigue life model for MCrAlY coated superalloys considering interfacial microstructure evolution","authors":"Mengqi Chen ,&nbsp;Jianan Song ,&nbsp;Jia Huang","doi":"10.1016/j.engfracmech.2024.110528","DOIUrl":"10.1016/j.engfracmech.2024.110528","url":null,"abstract":"<div><div>MCrAlY coatings, extensively utilized for safeguarding turbine blades against oxidation and erosion, encounter impediments due to inter-diffusion between the coating and substrate, thereby exacerbating fatigue life degradation at elevated temperatures. In this study, we introduce a novel approach involving the modification of critical depth in interfacial strain energy density to elucidate the impact of interfacial microstructure evolution on mechanical properties. Building upon this concept, we propose a fatigue life prediction model, which incorporates the dynamic evolution of interfacial structure and mechanical characteristics. Validation against empirical data underscores the commendable precision of the model. Our inquiry not only advances the comprehension of mechanical-chemical coupled behaviors but also yields significant insights for the optimization and maintenance of turbine blades.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110528"},"PeriodicalIF":4.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422623","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":"Fracture strength analysis of large-size and thin photovoltaic monocrystalline silicon wafers","authors":"Dameng Cheng,&nbsp;Yufei Gao,&nbsp;Guanzheng Li","doi":"10.1016/j.engfracmech.2024.110523","DOIUrl":"10.1016/j.engfracmech.2024.110523","url":null,"abstract":"<div><div>Diamond wire slicing technology is the main method to manufacture the substrate of the monocrystalline silicon-based solar cells. With the development of technology, the size and thickness of monocrystalline silicon wafer are respectively getting larger and thinner, which cause an increase in silicon wafer fracture probability during wafer processing and post-processing. And the change of the sawing speed, saw wire diameter and abrasive size also affect the wafer’s surface characteristics, thereby affect its fracture strength. In this paper, monocrystalline silicon wafer with large size of 210 mm × 210 mm was taken as the research object, 4-point bending test was carried out on each series of silicon wafers. The load–displacement curves during bending test were collected, and the fracture stress values were calculated by finite element method. The characteristic fracture strength and Weibull modulus of each series of silicon wafers were obtained through the statistical analysis of the data using Weibull distribution function. The effect of the silicon wafer thickness, the position of the silicon wafer in the silicon brick (usage time of the saw wire varies), and the bending test direction on the fracture characteristics was analyzed. The results showed that the increase of thickness increase the characteristic fracture strength of silicon wafer. The characteristic fracture strength of the front wafers (sawn by the fresh wire) is the smallest, while the characteristic fracture strength of the middle wafers and the rear wafers (sawn by the worn wire) are similar. The characteristic fracture strength of bending in the direction of perpendicular to the saw marks is 2–3 times that of bending in the direction of parallel to the saw marks. The reason of the difference of characteristic fracture strength was analyzed based on the surface morphology, roughness, and the saw marks of silicon wafer. In this paper, the fracture characteristics of large size monocrystalline silicon wafer are studied to provide fracture data support for industry production. The mechanism and main effect factors of silicon wafer fracture are revealed, which provides directions for improving the sawing quality and reducing the fracture probability during wafer production process and post-processing.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"310 ","pages":"Article 110523"},"PeriodicalIF":4.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357299","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}