Engineering Fracture Mechanics最新文献

Full-time domain rust expansion investigation and visual evaluation of reinforced concrete under synergistic protection

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110677

Dongya Ren , Zilin Wang , Lin Kong , Pengfei Wu , Jinkun Sun , Gang Dai , Changfa Ai

Reinforced concrete undergoes corrosion-induced expansion in chloride environments. To enhance the chloride resistance of reinforced concrete and analyze the corrosion behavior before and after protection, The steel bar was treated with a γ-aminopropyltriethoxysilane (KH550) solution using molecular self-assembly and incorporated a cementitious capillary crystalline waterproofing material during concrete mixing. Electrochemical tests accelerated chloride erosion, while digital image correlation (DIC) technology continuously monitored strain and displacement fields on the specimen’s surface. X-ray CT provided a three-dimensional visualization and analysis of corrosion products. Scanning electron microscopy and X-ray energy spectroscopy revealed the microstructural degradation and failure mechanisms of the concrete under various protective measures. The study indicates that chloride-induced rebar corrosion generates expansive stresses that drive the integration, coherence, and propagation of cracks in the concrete protective layer. Both silane coupling agent molecular coatings and cementitious capillary crystalline waterproofing material effectively inhibit chloride-induced rebar corrosion and delay the development of corrosion-induced cracks. Combined use of self-assembly technology and cementitious capillary crystalline waterproofing material offers superior resistance to chloride erosion compared to single protective measures.

{"title":"Full-time domain rust expansion investigation and visual evaluation of reinforced concrete under synergistic protection","authors":"Dongya Ren , Zilin Wang , Lin Kong , Pengfei Wu , Jinkun Sun , Gang Dai , Changfa Ai","doi":"10.1016/j.engfracmech.2024.110677","DOIUrl":"10.1016/j.engfracmech.2024.110677","url":null,"abstract":"<div><div>Reinforced concrete undergoes corrosion-induced expansion in chloride environments. To enhance the chloride resistance of reinforced concrete and analyze the corrosion behavior before and after protection, The steel bar was treated with a γ-aminopropyltriethoxysilane (KH550) solution using molecular self-assembly and incorporated a cementitious capillary crystalline waterproofing material during concrete mixing. Electrochemical tests accelerated chloride erosion, while digital image correlation (DIC) technology continuously monitored strain and displacement fields on the specimen’s surface. X-ray CT provided a three-dimensional visualization and analysis of corrosion products. Scanning electron microscopy and X-ray energy spectroscopy revealed the microstructural degradation and failure mechanisms of the concrete under various protective measures. The study indicates that chloride-induced rebar corrosion generates expansive stresses that drive the integration, coherence, and propagation of cracks in the concrete protective layer. Both silane coupling agent molecular coatings and cementitious capillary crystalline waterproofing material effectively inhibit chloride-induced rebar corrosion and delay the development of corrosion-induced cracks. Combined use of self-assembly technology and cementitious capillary crystalline waterproofing material offers superior resistance to chloride erosion compared to single protective measures.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110677"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164992","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}

引用次数: 0

Integrated preparation and compression behavior of novel 3D-Kagome lattice sandwich composite assembled by semi-rigid mortise-tenon joints

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110738

Yi Chang , Le Yang , Liang Gao , Minhui Xie , Zisu Li , Cuicui Zhang

Lightweight lattice sandwich composites have shown the excellent mechanical property and potential multi-functionality. As the classic lattice topology, the potential advantage of 3D-Kagome lattice core is well underutilized due to the preparation limitation. In this paper, a modified 3D-Kagome lattice core is designed, which can be sequentially assembled using three specific types of core-rods based on the clever semi-rigid mortise-tenon joints. The method perfectly resolves issues related to the overlapping of 3D-Kagome core-rods and weak connections between face-sheets and lattice cores. The mechanical properties of the Kagome lattice sandwich composites are investigated under out-of-plane and in-plane compression. The variations of out-of-plane compressive curves are analyzed to explore the multiple failure modes and quasi-static energy absorption mechanism. The different deformation patterns under in-plane compression are also recorded to illustrate the stiffness matching effect between face-sheets and lattice cores. Moreover, the effects of geometric parameters on the mechanical behaviors of sandwich structures are studied. Compared to the other lattice materials, the integrated 3D-Kagome lattice sandwich composites with the semi-rigid mortise-tenon joints demonstrate superior compressive properties, deformation tolerance, and energy absorption characteristics. These findings suggest that the sandwich structures with semi-rigid mortise-tenon joint are expected to show good bending and torsional properties.

{"title":"Integrated preparation and compression behavior of novel 3D-Kagome lattice sandwich composite assembled by semi-rigid mortise-tenon joints","authors":"Yi Chang , Le Yang , Liang Gao , Minhui Xie , Zisu Li , Cuicui Zhang","doi":"10.1016/j.engfracmech.2024.110738","DOIUrl":"10.1016/j.engfracmech.2024.110738","url":null,"abstract":"<div><div>Lightweight lattice sandwich composites have shown the excellent mechanical property and potential multi-functionality. As the classic lattice topology, the potential advantage of 3D-Kagome lattice core is well underutilized due to the preparation limitation. In this paper, a modified 3D-Kagome lattice core is designed, which can be sequentially assembled using three specific types of core-rods based on the clever semi-rigid mortise-tenon joints. The method perfectly resolves issues related to the overlapping of 3D-Kagome core-rods and weak connections between face-sheets and lattice cores. The mechanical properties of the Kagome lattice sandwich composites are investigated under out-of-plane and in-plane compression. The variations of out-of-plane compressive curves are analyzed to explore the multiple failure modes and quasi-static energy absorption mechanism. The different deformation patterns under in-plane compression are also recorded to illustrate the stiffness matching effect between face-sheets and lattice cores. Moreover, the effects of geometric parameters on the mechanical behaviors of sandwich structures are studied. Compared to the other lattice materials, the integrated 3D-Kagome lattice sandwich composites with the semi-rigid mortise-tenon joints demonstrate superior compressive properties, deformation tolerance, and energy absorption characteristics. These findings suggest that the sandwich structures with semi-rigid mortise-tenon joint are expected to show good bending and torsional properties.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110738"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164993","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}

引用次数: 0

Multivariate interpolation and machine learning models for extreme defects-based fatigue life prediction of Ti6Al4V specimens fabricated by SLM

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110756

Jan Horňas , Aleš Materna , Jonathan Glinz , Miroslav Yosifov , Sascha Senck

The paper proposes a novel methodology for extreme defects-based fatigue life prediction of Ti6Al4V specimens fabricated by selective laser melting (SLM) technique. The introduced framework is represented by a traditional ranking method based on the three highest values of maximum stress intensity factor (

K_{m a x}

) with related defect parameters (size, distance from the free surface, compactness and sphericity), training set augmentation using variational autoencoder (VAE) and optimized data-driven models. The defects were observed using micro-computed tomography (µ-CT) prior to the fatigue tests. As data-driven methods a multivariate interpolation and machine learning (ML) models were employed and tuned using Bayesian optimization algorithm called tree-structured Parzen estimator (TPE). The proposed methodology was validated on the test set and the highest prediction accuracy was achieved by random forest (RF) model with value of coefficient of determination

R_{test}^{2} = 0.956

. Additionally, the SHapley Additive exPlanations (SHAP) analysis was conducted to gain a deeper insights of applied data-driven models.

{"title":"Multivariate interpolation and machine learning models for extreme defects-based fatigue life prediction of Ti6Al4V specimens fabricated by SLM","authors":"Jan Horňas , Aleš Materna , Jonathan Glinz , Miroslav Yosifov , Sascha Senck","doi":"10.1016/j.engfracmech.2024.110756","DOIUrl":"10.1016/j.engfracmech.2024.110756","url":null,"abstract":"<div><div>The paper proposes a novel methodology for extreme defects-based fatigue life prediction of Ti6Al4V specimens fabricated by selective laser melting (SLM) technique. The introduced framework is represented by a traditional ranking method based on the three highest values of maximum stress intensity factor (<span><math><msub><mi>K</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span>) with related defect parameters (size, distance from the free surface, compactness and sphericity), training set augmentation using variational autoencoder (VAE) and optimized data-driven models. The defects were observed using micro-computed tomography (µ-CT) prior to the fatigue tests. As data-driven methods a multivariate interpolation and machine learning (ML) models were employed and tuned using Bayesian optimization algorithm called tree-structured Parzen estimator (TPE). The proposed methodology was validated on the test set and the highest prediction accuracy was achieved by random forest (RF) model with value of coefficient of determination <span><math><mrow><msubsup><mi>R</mi><mrow><mi>test</mi></mrow><mn>2</mn></msubsup><mo>=</mo><mn>0.956</mn></mrow></math></span>. Additionally, the SHapley Additive exPlanations (SHAP) analysis was conducted to gain a deeper insights of applied data-driven models.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110756"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165258","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}

引用次数: 0

Strength and damage constitutive model of backfill body after high temperature treatment

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110686

Rui Zhan, Bo Zhang, Lang Liu, Weiji Sun, Chao Huan, Haiwei Ji, Jin Zhang

Constructing mine heat storage reservoirs with water-blocking capabilities using functional filling technology is an innovative approach for underground high-temperature heat storage. However, high-temperature environments can easily cause thermal damage to the backfill body, posing significant risks to the safety of the heat storage reservoir. In this study, we conducted mechanical and microstructural tests on heated backfill body samples to observe changes in their mechanical properties and microstructure at varying temperatures. The test results show that as the temperature goes from room temperature (25 °C) to 350 °C, the backfill body’s compressive strength goes down a lot, with peak stress dropping from about 7 MPa to 3 MPa. At the same time, its ductility and ability to deform go up. Higher temperatures intensify shear failure, leading to the extension of cracks along the shear direction and subsequent surface spalling. The proportion of shear failure increased from 27.86 % to 68.21 %. The microstructure of ettringite, calcium silicate hydrate, and calcium hydroxide breaks down at different temperatures, which makes the pores bigger and the structure less rigid. This study developed a thermal damage constitutive model that incorporates acoustic emission parameters. We can use this model to evaluate and predict the deformation and strength characteristics of backfill after exposure to high-temperature treatment.

{"title":"Strength and damage constitutive model of backfill body after high temperature treatment","authors":"Rui Zhan, Bo Zhang, Lang Liu, Weiji Sun, Chao Huan, Haiwei Ji, Jin Zhang","doi":"10.1016/j.engfracmech.2024.110686","DOIUrl":"10.1016/j.engfracmech.2024.110686","url":null,"abstract":"<div><div>Constructing mine heat storage reservoirs with water-blocking capabilities using functional filling technology is an innovative approach for underground high-temperature heat storage. However, high-temperature environments can easily cause thermal damage to the backfill body, posing significant risks to the safety of the heat storage reservoir. In this study, we conducted mechanical and microstructural tests on heated backfill body samples to observe changes in their mechanical properties and microstructure at varying temperatures. The test results show that as the temperature goes from room temperature (25 °C) to 350 °C, the backfill body’s compressive strength goes down a lot, with peak stress dropping from about 7 MPa to 3 MPa. At the same time, its ductility and ability to deform go up. Higher temperatures intensify shear failure, leading to the extension of cracks along the shear direction and subsequent surface spalling. The proportion of shear failure increased from 27.86 % to 68.21 %. The microstructure of ettringite, calcium silicate hydrate, and calcium hydroxide breaks down at different temperatures, which makes the pores bigger and the structure less rigid. This study developed a thermal damage constitutive model that incorporates acoustic emission parameters. We can use this model to evaluate and predict the deformation and strength characteristics of backfill after exposure to high-temperature treatment.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110686"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165309","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}

引用次数: 0

On the crack-tip stress singularity in the Mooney-Rivlin material

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110734

L. Han, L.X. Li

Large deformation fracture of hyperelastic materials is a straightforward extension of the linear elastic fracture under small deformation, which is, however, more complicated and abundant for the crack-tip field. In this paper, the apparent singularity of crack-tip stress of the Mooney-Rivlin material is studied through the large deformation analysis. Firstly, the theoretical results of Cauchy and first Piola-Kirchhoff (PK1) asymptotic stress fields at the mode-I crack-tip are summarized for typical hyperelastic materials such as the neo-Hookean solid, the generalized neo-Hookean material and the exponentially hardening material. Next, a procedure is suggested for numerically computing the apparent singularity. Variations of the apparent singularities in the Cauchy stress

σ_{22}

and the PK1 stress

P_{22}

are finally obtained with the far-field applied strain for the Mooney-Rivlin material. The results show that the apparent singularity in

σ_{22}

is monotonically intensified from 1/2 (the asymptotic one at the infinitesimal strain) to 1 (the asymptotic one at the infinite strain), and it has a narrow interval of weakening oscillation in

P_{22}

, both of which appear in the range of small applied strains. These outcomes are explained by the mechanism that the zone of large deformation near the tip is rapidly enlarged during the change of far-field loading. The present work suggests that different hyperelastic models possess their apparent singularities of stress per se at the crack tip. This is helpful in establishing a criterion related to crack-tip singularity for precisely studying the constitutive law of hyperelastic materials.

{"title":"On the crack-tip stress singularity in the Mooney-Rivlin material","authors":"L. Han, L.X. Li","doi":"10.1016/j.engfracmech.2024.110734","DOIUrl":"10.1016/j.engfracmech.2024.110734","url":null,"abstract":"<div><div>Large deformation fracture of hyperelastic materials is a straightforward extension of the linear elastic fracture under small deformation, which is, however, more complicated and abundant for the crack-tip field. In this paper, the apparent singularity of crack-tip stress of the Mooney-Rivlin material is studied through the large deformation analysis. Firstly, the theoretical results of Cauchy and first Piola-Kirchhoff (PK1) asymptotic stress fields at the mode-I crack-tip are summarized for typical hyperelastic materials such as the neo-Hookean solid, the generalized neo-Hookean material and the exponentially hardening material. Next, a procedure is suggested for numerically computing the apparent singularity. Variations of the apparent singularities in the Cauchy stress <span><math><mrow><msub><mi>σ</mi><mn>22</mn></msub></mrow></math></span> and the PK1 stress <span><math><mrow><msub><mi>P</mi><mn>22</mn></msub></mrow></math></span> are finally obtained with the far-field applied strain for the Mooney-Rivlin material. The results show that the apparent singularity in <span><math><mrow><msub><mi>σ</mi><mn>22</mn></msub></mrow></math></span> is monotonically intensified from 1/2 (the asymptotic one at the infinitesimal strain) to 1 (the asymptotic one at the infinite strain), and it has a narrow interval of weakening oscillation in <span><math><mrow><msub><mi>P</mi><mn>22</mn></msub></mrow></math></span>, both of which appear in the range of small applied strains. These outcomes are explained by the mechanism that the zone of large deformation near the tip is rapidly enlarged during the change of far-field loading. The present work suggests that different hyperelastic models possess their apparent singularities of stress per se at the crack tip. This is helpful in establishing a criterion related to crack-tip singularity for precisely studying the constitutive law of hyperelastic materials.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110734"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165916","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}

引用次数: 0

Phase-field modeling of interfacial fracture in quasicrystal composites

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110731

Hongzhao Li , Weidong Li , Yu Tan , Xiandong Zhou , Haidong Fan , Qingyuan Wang , Peidong Li

Quasicrystals (QCs) have been used as a particle reinforcement phase in polymer or metal matrix composites to enhance the material strength, hardness and wear resistance while maintaining the lightweight advantages of the composites. In this paper, a phase-field fracture model (PFM) is proposed to predict crack propagation and interfacial debonding in QC composites. The phase-field and interface-field variables are introduced to regularize the cracks and interfaces in the composites, respectively. An equivalent critical energy release rate is introduced to characterize the influence of the interface on crack propagation. The present model is numerically implemented in Comsol Multiphysics based on the Weak Form PDE module. Several numerical examples are simulated to demonstrate the ability of the proposed model to predict crack propagation and interfacial failure of QC composites and to analyze the influence of QC reinforcement phase on fracture behaviors of QC composites. Numerical results indicate that the interface significantly influences the crack propagation paths, and the phason elastic field has a remarkable influence on the peak force and failure displacement in the fracture test of QC composites. The developed phase-field model and numeral implementation approach provide a convenient tool for predicting interfacial failure and assessing the safety of QC composites in engineering.

{"title":"Phase-field modeling of interfacial fracture in quasicrystal composites","authors":"Hongzhao Li , Weidong Li , Yu Tan , Xiandong Zhou , Haidong Fan , Qingyuan Wang , Peidong Li","doi":"10.1016/j.engfracmech.2024.110731","DOIUrl":"10.1016/j.engfracmech.2024.110731","url":null,"abstract":"<div><div>Quasicrystals (QCs) have been used as a particle reinforcement phase in polymer or metal matrix composites to enhance the material strength, hardness and wear resistance while maintaining the lightweight advantages of the composites. In this paper, a phase-field fracture model (PFM) is proposed to predict crack propagation and interfacial debonding in QC composites. The phase-field and interface-field variables are introduced to regularize the cracks and interfaces in the composites, respectively. An equivalent critical energy release rate is introduced to characterize the influence of the interface on crack propagation. The present model is numerically implemented in <span>Comsol</span> Multiphysics based on the W<span>eak</span> F<span>orm</span> PDE module. Several numerical examples are simulated to demonstrate the ability of the proposed model to predict crack propagation and interfacial failure of QC composites and to analyze the influence of QC reinforcement phase on fracture behaviors of QC composites. Numerical results indicate that the interface significantly influences the crack propagation paths, and the phason elastic field has a remarkable influence on the peak force and failure displacement in the fracture test of QC composites. The developed phase-field model and numeral implementation approach provide a convenient tool for predicting interfacial failure and assessing the safety of QC composites in engineering.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110731"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166099","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}

引用次数: 0

Direct mixed-mode I&II partitioning in beam-like geometries using Digital Image Correlation and the decomposed J-integral

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110704

Lucas Binsfeld , Riccardo Bonato , Zeno Pagliaro , Neal Murphy , Alojz Ivankoviç

In the current work, a direct method of mode partitioning is developed, based on the application of the partitioned

J

-integral to strain fields directly measured using Digital Image Correlation. The method has first been validated using strain fields obtained from Finite Element Analysis of Double Cantilever Beam, End-Loaded Split and Fixed-Ratio Mixed-Mode test specimen geometries. Then, a Cracked Lap Shear specimen has been designed, modelled and tested. Very good agreement was achieved for all standard specimens. As for the Cracked Lap Shear geometry, there are no accepted partitioning solutions. The new direct mixed-mode partitioning method results in

\frac{G_{I}}{G_{I I}} = 0.35

. This method has also been successfully extended to asymmetric cases using the Asymmetric Fixed Ratio Mixed Mode test specimen with 5 different beam thickness ratios:

γ

= 0.5, 1, 1.8, 3 & 3.94. The results are found to compare very well with both FEA and the semi-analytical cohesive analysis (SACA) partitioning method from Conroy et al. (2015).

{"title":"Direct mixed-mode I&II partitioning in beam-like geometries using Digital Image Correlation and the decomposed J-integral","authors":"Lucas Binsfeld , Riccardo Bonato , Zeno Pagliaro , Neal Murphy , Alojz Ivankoviç","doi":"10.1016/j.engfracmech.2024.110704","DOIUrl":"10.1016/j.engfracmech.2024.110704","url":null,"abstract":"<div><div>In the current work, a direct method of mode partitioning is developed, based on the application of the partitioned <span><math><mi>J</mi></math></span>-integral to strain fields directly measured using Digital Image Correlation. The method has first been validated using strain fields obtained from Finite Element Analysis of Double Cantilever Beam, End-Loaded Split and Fixed-Ratio Mixed-Mode test specimen geometries. Then, a Cracked Lap Shear specimen has been designed, modelled and tested. Very good agreement was achieved for all standard specimens. As for the Cracked Lap Shear geometry, there are no accepted partitioning solutions. The new direct mixed-mode partitioning method results in <span><math><mrow><mfrac><mrow><msub><mrow><mi>G</mi></mrow><mrow><mi>I</mi></mrow></msub></mrow><mrow><msub><mrow><mi>G</mi></mrow><mrow><mi>I</mi><mi>I</mi></mrow></msub></mrow></mfrac><mo>=</mo><mn>0</mn><mo>.</mo><mn>35</mn></mrow></math></span>. This method has also been successfully extended to asymmetric cases using the Asymmetric Fixed Ratio Mixed Mode test specimen with 5 different beam thickness ratios: <span><math><mi>γ</mi></math></span> = 0.5, 1, 1.8, 3 & 3.94. The results are found to compare very well with both FEA and the semi-analytical cohesive analysis (SACA) partitioning method from Conroy et al. (2015).</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110704"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165255","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}

引用次数: 0

The influence of rolling process on fatigue properties of 316L/2Cr13 multilayered steel and analysis of its fracture process

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110726

Xin Zhou , Rui Cao , Jingping Ma , Xiaoxia Jiang , Yingjie Yan

In order to investigate the effect of the rolling process on the fatigue properties of 316L/2Cr13 Multilayered Steel (MLS), high-cycle fatigue tests of MLS at a stress ratio of 0.1 are performed on the universal testing machine. The MLS composed of the austenitic stainless steel 316L and martensitic stainless steel 2Cr13 is prepared by accumulative roll-bonding (ARB). Furthermore, MLS is prepared under a variety of rolling temperatures and rolling sequences. The changes of microstructure and properties as well as fracture mechanism are analyzed by means of Scanning Electron Microscope (SEM), Electron Back Scatter Diffraction (EBSD), tensile tests, fatigue tests and interruption tests. The results reveal that in contrast to the full martensite and full austenitic MLS, the fatigue properties of 316L/2Cr13 MLS are improved. When the rolling process is “1130℃ 4 + 6 passes” and “1200℃ 10 passes”, the MLS possesses the optimal performance. In addition, the fatigue strength of MLS first increases and then decreases with the increase of tensile strength. Interruption test shows that the fatigue crack of multilayered steel starts from ferrite phase of 2Cr13 layer. When the crack propagates, if there are cracks initiated by adjacent 2Cr13 layers near the crack tip, the crack will connect and accelerate the propagation rate.

{"title":"The influence of rolling process on fatigue properties of 316L/2Cr13 multilayered steel and analysis of its fracture process","authors":"Xin Zhou , Rui Cao , Jingping Ma , Xiaoxia Jiang , Yingjie Yan","doi":"10.1016/j.engfracmech.2024.110726","DOIUrl":"10.1016/j.engfracmech.2024.110726","url":null,"abstract":"<div><div>In order to investigate the effect of the rolling process on the fatigue properties of 316L/2Cr13 Multilayered Steel (MLS), high-cycle fatigue tests of MLS at a stress ratio of 0.1 are performed on the universal testing machine. The MLS composed of the austenitic stainless steel 316L and martensitic stainless steel 2Cr13 is prepared by accumulative roll-bonding (ARB). Furthermore, MLS is prepared under a variety of rolling temperatures and rolling sequences. The changes of microstructure and properties as well as fracture mechanism are analyzed by means of Scanning Electron Microscope (SEM), Electron Back Scatter Diffraction (EBSD), tensile tests, fatigue tests and interruption tests. The results reveal that in contrast to the full martensite and full austenitic MLS, the fatigue properties of 316L/2Cr13 MLS are improved. When the rolling process is “1130℃ 4 + 6 passes” and “1200℃ 10 passes”, the MLS possesses the optimal performance. In addition, the fatigue strength of MLS first increases and then decreases with the increase of tensile strength. Interruption test shows that the fatigue crack of multilayered steel starts from ferrite phase of 2Cr13 layer. When the crack propagates, if there are cracks initiated by adjacent 2Cr13 layers near the crack tip, the crack will connect and accelerate the propagation rate.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110726"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165863","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}

引用次数: 0

Experimental and numerical simulation study of rough jointed rock samples under triaxial compression conditions

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110707

Renliang Shan, Nianzeng Liu, Peng Sun, Ziyue Zhao, Ruiyu Dong, Haoyu Dou, Haozhe Meng, Yao Bai

The presence of joint planes significantly affects the mechanical properties of rock and poses a threat to the safety of engineering construction. To examine the influence of Joint Roughness Coefficient (JRC) and joint plane inclination on the mechanical behavior of jointed rock masses, this research employed 3D printing technology to fabricate jointed rock samples with varying JRC and joint inclination angles. Triaxial compression tests were then conducted on these samples in the laboratory. The results indicate that an increase in JRC strengthens the serrated interlocking effect of joint planes, leading to a corresponding increase in both the peak failure strength and elastic modulus of samples with different inclination angles. For samples with the same JRC, the peak strength initially decreases with increasing inclination angle, followed by a subsequent rise. The variation trend of Poisson’s ratio, however, shows the opposite pattern. The joint inclination significantly impacts the failure mode of the samples. However, as JRC changes, the failure mode does not show significant variation. Furthermore, drawing from the laboratory test results, numerical simulations were performed using the Particle Flow Code in 2 Dimensions (PFC2D) to analyze mesoscopic crack propagation mechanisms in jointed rock models subjected to triaxial compression. Finally, this research discusses the effects of JRC and joint plane inclination on the anisotropic characteristics of jointed samples and offers a detailed analysis of the failure mechanisms.

{"title":"Experimental and numerical simulation study of rough jointed rock samples under triaxial compression conditions","authors":"Renliang Shan, Nianzeng Liu, Peng Sun, Ziyue Zhao, Ruiyu Dong, Haoyu Dou, Haozhe Meng, Yao Bai","doi":"10.1016/j.engfracmech.2024.110707","DOIUrl":"10.1016/j.engfracmech.2024.110707","url":null,"abstract":"<div><div>The presence of joint planes significantly affects the mechanical properties of rock and poses a threat to the safety of engineering construction. To examine the influence of Joint Roughness Coefficient (<em>JRC</em>) and joint plane inclination on the mechanical behavior of jointed rock masses, this research employed 3D printing technology to fabricate jointed rock samples with varying <em>JRC</em> and joint inclination angles. Triaxial compression tests were then conducted on these samples in the laboratory. The results indicate that an increase in <em>JRC</em> strengthens the serrated interlocking effect of joint planes, leading to a corresponding increase in both the peak failure strength and elastic modulus of samples with different inclination angles. For samples with the same <em>JRC</em>, the peak strength initially decreases with increasing inclination angle, followed by a subsequent rise. The variation trend of Poisson’s ratio, however, shows the opposite pattern. The joint inclination significantly impacts the failure mode of the samples. However, as <em>JRC</em> changes, the failure mode does not show significant variation. Furthermore, drawing from the laboratory test results, numerical simulations were performed using the Particle Flow Code in 2 Dimensions (PFC2D) to analyze mesoscopic crack propagation mechanisms in jointed rock models subjected to triaxial compression. Finally, this research discusses the effects of <em>JRC</em> and joint plane inclination on the anisotropic characteristics of jointed samples and offers a detailed analysis of the failure mechanisms.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110707"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165864","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}

引用次数: 0

Two-dimensional weight function of stress intensity factors for surface cracks emanating from weld toes of butt-welded plates

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110723

Mengqi Gu , Wanlin Guo

The two-dimensional weight function method, which is proposed by Wang and Glinka (2009), is adopted here to calculate stress intensity factors for surface cracks emanating from weld toes of butt-welded plates with different toe angles. Two-dimensional point load weight function is derived based on reference stress intensity factors and accurate stress distribution on virtual crack face obtained from comprehensive finite element analyses. The obtained weight function is validated against finite element calculations and shows high accuracy. Explicit fitted empirical formulae are obtained for semi-elliptical surface cracks with wide ranges of crack aspect ratio

0.2 ⩽ a / c ⩽ 1.0

, crack depth ratio

0.2 ⩽ a / B ⩽ 0.9

, crack angular parameter

0.05 ⩽ 2 ϕ / π ⩽ 0.95

, at weld toes with toe angles

φ = 0^{°}, 15^{°}, 30^{°}, 45^{°}

and toe radius ratio

r / B = 0.0, 0.1, 0.2, 0.3

for quick fatigue crack growth prediction in engineering structures providing a foundation for durability and damage tolerance design. It is shown that sharp transition (

r / B = 0.0

) between the weld toe and the base metal will lead to a significant increase of weight function coefficient M at the front of shallow cracks (

a / B = 0.02

) near the surface.

{"title":"Two-dimensional weight function of stress intensity factors for surface cracks emanating from weld toes of butt-welded plates","authors":"Mengqi Gu , Wanlin Guo","doi":"10.1016/j.engfracmech.2024.110723","DOIUrl":"10.1016/j.engfracmech.2024.110723","url":null,"abstract":"<div><div>The two-dimensional weight function method, which is proposed by Wang and Glinka (2009), is adopted here to calculate stress intensity factors for surface cracks emanating from weld toes of butt-welded plates with different toe angles. Two-dimensional point load weight function is derived based on reference stress intensity factors and accurate stress distribution on virtual crack face obtained from comprehensive finite element analyses. The obtained weight function is validated against finite element calculations and shows high accuracy. Explicit fitted empirical formulae are obtained for semi-elliptical surface cracks with wide ranges of crack aspect ratio <span><math><mrow><mn>0.2</mn><mo>⩽</mo><mrow><mi>a</mi><mo>/</mo><mi>c</mi></mrow><mo>⩽</mo><mn>1.0</mn></mrow></math></span>, crack depth ratio <span><math><mrow><mn>0.2</mn><mo>⩽</mo><mrow><mi>a</mi><mo>/</mo><mi>B</mi></mrow><mo>⩽</mo><mn>0.9</mn></mrow></math></span>, crack angular parameter <span><math><mrow><mn>0.05</mn><mrow><mrow><mo>⩽</mo><mn>2</mn><mi>ϕ</mi></mrow><mo>/</mo><mi>π</mi></mrow><mo>⩽</mo><mn>0.95</mn></mrow></math></span>, at weld toes with toe angles <span><math><mrow><mi>φ</mi><mo>=</mo><msup><mn>0</mn><mo>°</mo></msup><mrow><mtext>,</mtext><mspace></mspace></mrow><msup><mn>15</mn><mo>°</mo></msup><mrow><mtext>,</mtext><mspace></mspace></mrow><msup><mn>30</mn><mo>°</mo></msup><mo>,</mo><msup><mn>45</mn><mo>°</mo></msup></mrow></math></span> and toe radius ratio <span><math><mrow><mrow><mi>r</mi><mo>/</mo><mi>B</mi></mrow><mo>=</mo><mn>0.0</mn><mo>,</mo><mn>0.1</mn><mo>,</mo><mn>0.2</mn><mo>,</mo><mn>0.3</mn></mrow></math></span> for quick fatigue crack growth prediction in engineering structures providing a foundation for durability and damage tolerance design. It is shown that sharp transition (<span><math><mrow><mrow><mi>r</mi><mo>/</mo><mi>B</mi></mrow><mo>=</mo><mn>0.0</mn></mrow></math></span>) between the weld toe and the base metal will lead to a significant increase of weight function coefficient <em>M</em> at the front of shallow cracks (<span><math><mrow><mrow><mi>a</mi><mo>/</mo><mi>B</mi></mrow><mrow><mspace></mspace><mtext>= 0.02</mtext></mrow></mrow></math></span>) near the surface.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110723"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165865","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}

引用次数: 0