Engineering Fracture Mechanics最新文献

The splitting fatigue properties of ultra-large particle size asphalt mixture under the coupling effect of temperature and load

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-03 DOI: 10.1016/j.engfracmech.2025.110990

Tian Tian , Yingjun Jiang , Yong Yi , Chenliang Nie

In this work, the ultra-large particle size asphalt mixture (LSAM-50) was initially molded through the vertical vibration test method, producing cylindrical specimens. Subsequently, the influence of temperature, oil-to-aggregate ratio, and maximum aggregate particle size on the splitting properties was meticulously examined through splitting tests. This investigation culminated in the construction of a temperature-dependent model for this mechanical property. Furthermore, the impact of temperature and stress levels on the splitting fatigue performance was probed, leading to the development and verification of a fatigue equation for LSAM-50 under the combined effect of temperature and load, which was confirmed through indoor fatigue tests conducted at low stress levels. The findings revealed a notable trend: the splitting tensile strength and failure stiffness modulus diminish as temperature increases, with the rate of decrease gradually slowing over time, and the failure tensile strain exhibits an opposing trend. Across a spectrum of temperatures, the splitting tensile strength of asphalt mixtures tends to enhance as the maximum aggregate particle size increases. The cohesive force, denoted as ’c,’ presents an ’inverse S-shaped’ curve with escalating temperature, while the internal friction angle, represented by ’φ,’ remains relatively stable with temperature fluctuations. The Boltzmann function emerges as an effective means to characterize the temperature dependency of the splitting characteristics, boasting an R² value exceeding 0.98. The splitting fatigue life progressively diminishes with the increase in temperature (or stress level), with the fatigue equation under the combined influence of temperature and load expressed as lgN=(4.72–0.076T)-(3.12–0.027T)lg(σ-σ_th), where the fatigue limit σ_th = 0.072e^-0.046^T and R² > 0.85. The overall pattern of LSAM-50′s splitting fatigue life in the low stress region aligns with the curve described by the fatigue equation. The outcomes of this research have laid a solid foundation for the design of LSAM-50, offering invaluable insights into its performance characteristics under various conditions.

{"title":"The splitting fatigue properties of ultra-large particle size asphalt mixture under the coupling effect of temperature and load","authors":"Tian Tian , Yingjun Jiang , Yong Yi , Chenliang Nie","doi":"10.1016/j.engfracmech.2025.110990","DOIUrl":"10.1016/j.engfracmech.2025.110990","url":null,"abstract":"<div><div>In this work, the ultra-large particle size asphalt mixture (LSAM-50) was initially molded through the vertical vibration test method, producing cylindrical specimens. Subsequently, the influence of temperature, oil-to-aggregate ratio, and maximum aggregate particle size on the splitting properties was meticulously examined through splitting tests. This investigation culminated in the construction of a temperature-dependent model for this mechanical property. Furthermore, the impact of temperature and stress levels on the splitting fatigue performance was probed, leading to the development and verification of a fatigue equation for LSAM-50 under the combined effect of temperature and load, which was confirmed through indoor fatigue tests conducted at low stress levels. The findings revealed a notable trend: the splitting tensile strength and failure stiffness modulus diminish as temperature increases, with the rate of decrease gradually slowing over time, and the failure tensile strain exhibits an opposing trend. Across a spectrum of temperatures, the splitting tensile strength of asphalt mixtures tends to enhance as the maximum aggregate particle size increases. The cohesive force, denoted as ’<em>c</em>,’ presents an ’inverse <em>S</em>-shaped’ curve with escalating temperature, while the internal friction angle, represented by ’<em>φ</em>,’ remains relatively stable with temperature fluctuations. The Boltzmann function emerges as an effective means to characterize the temperature dependency of the splitting characteristics, boasting an <em>R</em><sup>2</sup> value exceeding 0.98. The splitting fatigue life progressively diminishes with the increase in temperature (or stress level), with the fatigue equation under the combined influence of temperature and load expressed as lg<em>N</em>=(4.72–0.076<em>T</em>)-(3.12–0.027<em>T</em>)lg(<em>σ</em>-<em>σ</em><sub>th</sub>), where the fatigue limit <em>σ</em><sub>th</sub> = 0.072<em>e</em><sup>-0.046</sup><em><sup>T</sup></em> and <em>R</em><sup>2</sup> > 0.85. The overall pattern of LSAM-50′s splitting fatigue life in the low stress region aligns with the curve described by the fatigue equation. The outcomes of this research have laid a solid foundation for the design of LSAM-50, offering invaluable insights into its performance characteristics under various conditions.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110990"},"PeriodicalIF":4.7,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551694","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

A pre-tension based adhesion-tuning approach: Bridging the gap in peeling test research and application

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-03 DOI: 10.1016/j.engfracmech.2025.110980

Junjun Chen, Hongshi Ruan, Xiaozhe Ju, Yangjian Xu, Xing Chen, Changliang Pan, Lihua Liang

Typically, peeling force increases with a decrease in peeling angle. Thus, altering the peeling angle serves as an effective means of modulating the peeling force. Research indicates that in numerous attachment and detachment applications, such as a gecko climbing on a ceiling, enhancing the normal component of peeling force is critical. However, significant changes to this force component through angle adjustment are limited. Therefore, a novel pre-tension-based attachment and detachment method considering tangential constraints was proposed here, which significantly broadens the range of normal peeling force variation, facilitating the development of various innovative applications. Subsequently, analytical solutions were derived for these peeling models, and the relationship between the normal peeling force and pre-tension was revealed. Furthermore, a finite element simulation method for peeling tests with pre-tension was introduced, and the analytical solutions were validated. Ultimately, the efficacy of the developed method was further qualitatively confirmed through experimental peeling tests. This study provides a novel perspective on the application of peeling tests and offers valuable insights for future research in this domain.

{"title":"A pre-tension based adhesion-tuning approach: Bridging the gap in peeling test research and application","authors":"Junjun Chen, Hongshi Ruan, Xiaozhe Ju, Yangjian Xu, Xing Chen, Changliang Pan, Lihua Liang","doi":"10.1016/j.engfracmech.2025.110980","DOIUrl":"10.1016/j.engfracmech.2025.110980","url":null,"abstract":"<div><div>Typically, peeling force increases with a decrease in peeling angle. Thus, altering the peeling angle serves as an effective means of modulating the peeling force. Research indicates that in numerous attachment and detachment applications, such as a gecko climbing on a ceiling, enhancing the normal component of peeling force is critical. However, significant changes to this force component through angle adjustment are limited. Therefore, a novel pre-tension-based attachment and detachment method considering tangential constraints was proposed here, which significantly broadens the range of normal peeling force variation, facilitating the development of various innovative applications. Subsequently, analytical solutions were derived for these peeling models, and the relationship between the normal peeling force and pre-tension was revealed. Furthermore, a finite element simulation method for peeling tests with pre-tension was introduced, and the analytical solutions were validated. Ultimately, the efficacy of the developed method was further qualitatively confirmed through experimental peeling tests. This study provides a novel perspective on the application of peeling tests and offers valuable insights for future research in this domain.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110980"},"PeriodicalIF":4.7,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551724","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

Impact tensile test and numerical analysis of the dynamic behavior of sandstone ring specimens using a split Hopkinson hollow tensile bar

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-02 DOI: 10.1016/j.engfracmech.2025.111004

Shi Liu , Chuanxin Cai , Shaoxu Hao , Yue Zhai , Xiquan Jiang , Xuqi Liang

Most rock bodies encountered in underground engineering projects are subject to dynamic tensile conditions. The purpose of this study is to analyze the feasibility of using hollow circular rock samples in a dynamic direct tensile test and assess the specimen’s dynamic tensile mechanical properties. We used 26 hollow ring red sandstone specimens (HRRSSs) with different strain rates (53.86 s⁻¹ to 104.44 s⁻¹ in dynamic direct tensile tests using a Split Hopkinson Hollow Tensile Bar (SHHTB) test system. Five parameters, i.e., the initial elastic modulus, elastoplastic modulus, ideal elastic energy, ideal elastic coefficient, and energy dissipation ratio, were used to identify five stress stages during loading. The parameters were used to analyze the stiffness and energy evolution of the HRRSSs during loading. Numerical methods were utilized to simulate the damage evolution and destruction of the 12 specimens under dynamic tensile loading. The experimental and numerical results showed that the hollow ring structure was reliable and effective in determining the dynamic and direct tensile mechanical properties of rock materials and expanded the upper limit of the strain rate. The direct tensile failure of the HRRSSs with a low strain rate was due to the connection of multiple weak surfaces, whereas that of the HRRSSs with a high strain rate occurred due to a central stress concentration area that consumed a large amount of plastic energy by penetrating a strong surface. The proposed testing method, specimen type, and analytical models can be used to investigate the mechanical properties of rocks using dynamic direct tensile tests.

{"title":"Impact tensile test and numerical analysis of the dynamic behavior of sandstone ring specimens using a split Hopkinson hollow tensile bar","authors":"Shi Liu , Chuanxin Cai , Shaoxu Hao , Yue Zhai , Xiquan Jiang , Xuqi Liang","doi":"10.1016/j.engfracmech.2025.111004","DOIUrl":"10.1016/j.engfracmech.2025.111004","url":null,"abstract":"<div><div>Most rock bodies encountered in underground engineering projects are subject to dynamic tensile conditions. The purpose of this study is to analyze the feasibility of using hollow circular rock samples in a dynamic direct tensile test and assess the specimen’s dynamic tensile mechanical properties. We used 26 hollow ring red sandstone specimens (HRRSSs) with different strain rates (53.86 s<sup>−1</sup> to 104.44 s<sup>−1</sup> in dynamic direct tensile tests using a Split Hopkinson Hollow Tensile Bar (SHHTB) test system. Five parameters, i.e., the initial elastic modulus, elastoplastic modulus, ideal elastic energy, ideal elastic coefficient, and energy dissipation ratio, were used to identify five stress stages during loading. The parameters were used to analyze the stiffness and energy evolution of the HRRSSs during loading. Numerical methods were utilized to simulate the damage evolution and destruction of the 12 specimens under dynamic tensile loading. The experimental and numerical results showed that the hollow ring structure was reliable and effective in determining the dynamic and direct tensile mechanical properties of rock materials and expanded the upper limit of the strain rate. The direct tensile failure of the HRRSSs with a low strain rate was due to the connection of multiple weak surfaces, whereas that of the HRRSSs with a high strain rate occurred due to a central stress concentration area that consumed a large amount of plastic energy by penetrating a strong surface. The proposed testing method, specimen type, and analytical models can be used to investigate the mechanical properties of rocks using dynamic direct tensile tests.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 111004"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551590","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

Multiscale analysis of carbon microfiber reinforcement on fracture behavior of ultra-high-performance concrete

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-02 DOI: 10.1016/j.engfracmech.2025.110998

J.D. Ríos , H. Cifuentes , G. Ruiz , D.C. González , M.A. Vicente , R.C. Yu , C. Leiva

This study delves into the intricate world of ultra-high-performance concrete, specifically how its mechanical integrity and fracture resistance are influenced by the incorporation of carbon microfibers of varying lengths. Employing a suite of multiscale analytical techniques, we link the mechanical attributes of concrete to its microstructural composition, with a keen focus on porosity distribution as revealed by advanced X-ray computed tomography and porosimetry assessments. We uncover how the selection of microfiber type affects the concrete’s internal pore landscape, which in turn dictates the material’s fracture behavior. An innovative use of inverse analysis, based on established fracture mechanics, allows us to formulate cohesive laws for the fracture process zone. Our results uncover a direct correlation between the variability in fracture properties and the specific types and amounts of fibers used, providing mix designers with critical insights for customizing concrete formulations to meet precise performance criteria.

{"title":"Multiscale analysis of carbon microfiber reinforcement on fracture behavior of ultra-high-performance concrete","authors":"J.D. Ríos , H. Cifuentes , G. Ruiz , D.C. González , M.A. Vicente , R.C. Yu , C. Leiva","doi":"10.1016/j.engfracmech.2025.110998","DOIUrl":"10.1016/j.engfracmech.2025.110998","url":null,"abstract":"<div><div>This study delves into the intricate world of ultra-high-performance concrete, specifically how its mechanical integrity and fracture resistance are influenced by the incorporation of carbon microfibers of varying lengths. Employing a suite of multiscale analytical techniques, we link the mechanical attributes of concrete to its microstructural composition, with a keen focus on porosity distribution as revealed by advanced X-ray computed tomography and porosimetry assessments. We uncover how the selection of microfiber type affects the concrete’s internal pore landscape, which in turn dictates the material’s fracture behavior. An innovative use of inverse analysis, based on established fracture mechanics, allows us to formulate cohesive laws for the fracture process zone. Our results uncover a direct correlation between the variability in fracture properties and the specific types and amounts of fibers used, providing mix designers with critical insights for customizing concrete formulations to meet precise performance criteria.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110998"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551696","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 role of burial depth on the structural plane-controlled rock burst failure characteristics of circular hard rock tunnels under true triaxial conditions

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-02 DOI: 10.1016/j.engfracmech.2025.111003

Zhen-Rui Zhang , Shun-Chuan Wu , Zhi-Yuan Xia , Long-Qiang Han , Hai-Yong Cheng , Ji-Quan Ma

Deep rock mass excavation, very easy to induce rockburst disaster, the structural plane has an important role in controlling rockbursts, with the development of underground engineering to the deep part of the earth, the depth of burial on the structural Plane-Controlled Rockbursts more and more prominent, in order to study the impact of the depth of burial on the structural Plane-Controlled Rockbursts, this paper adopts the use of red sandstone to make a cubic specimen of 100 mm * 100 mm * 100 mm containing 50 mm round holes, prefabricated fissure simulation structural plane surface, simulating 500 m, 800 m, 1000 m, 1200 m and 1500 m depth of burial pressure conditions to carry out a series of true triaxial compression test, comparative analysis of different burial depth conditions with or without structural plane specimens of rockburst evolution, damage mechanisms and fractal characteristics of debris, the results show that the structural plane of the rock mass of rockburst evolution stage has undergone significant changes, can be divided into a calm stage, violent damage and micro-cracking Expansion stage, plate fracture flexure stage, violent failure stage (secondary rockburst).AE evolution process can be divided into microcrack closure and linear elasticity stage, cracks non-stable development and rockburst stage, cracks sprouting and stable expansion stage and cracks non-stable development to rockburst stage. Structural plane specimens rockburst intensity is greater than that of the unstructured specimens, the high burial depth environment has a certain inhibition of the occurrence of rockburst, but the rockburst danger and rockburst intensity will be enhanced. No structural plane rock mass failure process is non-linear and progressive, structural plane rockburst has a “sudden” “transient” characteristics.

{"title":"The role of burial depth on the structural plane-controlled rock burst failure characteristics of circular hard rock tunnels under true triaxial conditions","authors":"Zhen-Rui Zhang , Shun-Chuan Wu , Zhi-Yuan Xia , Long-Qiang Han , Hai-Yong Cheng , Ji-Quan Ma","doi":"10.1016/j.engfracmech.2025.111003","DOIUrl":"10.1016/j.engfracmech.2025.111003","url":null,"abstract":"<div><div>Deep rock mass excavation, very easy to induce rockburst disaster, the structural plane has an important role in controlling rockbursts, with the development of underground engineering to the deep part of the earth, the depth of burial on the structural Plane-Controlled Rockbursts more and more prominent, in order to study the impact of the depth of burial on the structural Plane-Controlled Rockbursts, this paper adopts the use of red sandstone to make a cubic specimen of 100 mm * 100 mm * 100 mm containing 50 mm round holes, prefabricated fissure simulation structural plane surface, simulating 500 m, 800 m, 1000 m, 1200 m and 1500 m depth of burial pressure conditions to carry out a series of true triaxial compression test, comparative analysis of different burial depth conditions with or without structural plane specimens of rockburst evolution, damage mechanisms and fractal characteristics of debris, the results show that the structural plane of the rock mass of rockburst evolution stage has undergone significant changes, can be divided into a calm stage, violent damage and micro-cracking Expansion stage, plate fracture flexure stage, violent failure stage (secondary rockburst).AE evolution process can be divided into microcrack closure and linear elasticity stage, cracks non-stable development and rockburst stage, cracks sprouting and stable expansion stage and cracks non-stable development to rockburst stage. Structural plane specimens rockburst intensity is greater than that of the unstructured specimens, the high burial depth environment has a certain inhibition of the occurrence of rockburst, but the rockburst danger and rockburst intensity will be enhanced. No structural plane rock mass failure process is non-linear and progressive, structural plane rockburst has a “sudden” “transient” characteristics.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 111003"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551708","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

Damage mechanism of REBCO coated conductor in CORC cables under electromagnetic loading

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-02 DOI: 10.1016/j.engfracmech.2025.111001

Jintao Ma , Wurui Ta , Jiangtao Yan , Zhiwen Jin , Yuanwen Gao , Youhe Zhou

The performance of Conductor on Round Core (CORC) cables in complex electromagnetic environments is crucial for the safe operation of large superconducting magnet systems. As a critical component, the delamination issue of rare-earth-barium-copper-oxide (REBCO) coated conductors plays an important role in the mechanical and electrical stability of CORC cables. In this paper, the distribution characteristics of current density, electromagnetic force, interfacial stress, and delamination damage of REBCO coated conductors in CORC cables under different background fields are presented using a combined electromagnetic damage model. The numerical results indicate that the magnitude and direction of the electromagnetic force vary periodically with the sinusoidal magnetic field. The frequency of the external magnetic field has minimal influence on the current density and electromagnetic force. When the magnetic field and the transport current intervene together, the interaction between the transport current and the shielding current induced by the magnetic field significantly changes the distribution of the current density and the electromagnetic force, which further affects the interfacial stress and the delamination propagation path of the cohesive layer. The magnitudes of current density and electromagnetic force are proportional to the slopes of the variation curves of the transport current and magnetic field. Notably, in both scenarios, the interfacial shear delamination stress shows a clear tendency to concentrate at the edges of REBCO coated conductor, which is the primary factor driving interfacial delamination and crack propagation. Therefore, accurately measuring the shear delamination strength of REBCO coated conductors is highly significant for determining their operational limits under multi-field conditions.

{"title":"Damage mechanism of REBCO coated conductor in CORC cables under electromagnetic loading","authors":"Jintao Ma , Wurui Ta , Jiangtao Yan , Zhiwen Jin , Yuanwen Gao , Youhe Zhou","doi":"10.1016/j.engfracmech.2025.111001","DOIUrl":"10.1016/j.engfracmech.2025.111001","url":null,"abstract":"<div><div>The performance of Conductor on Round Core (CORC) cables in complex electromagnetic environments is crucial for the safe operation of large superconducting magnet systems. As a critical component, the delamination issue of rare-earth-barium-copper-oxide (REBCO) coated conductors plays an important role in the mechanical and electrical stability of CORC cables. In this paper, the distribution characteristics of current density, electromagnetic force, interfacial stress, and delamination damage of REBCO coated conductors in CORC cables under different background fields are presented using a combined electromagnetic damage model. The numerical results indicate that the magnitude and direction of the electromagnetic force vary periodically with the sinusoidal magnetic field. The frequency of the external magnetic field has minimal influence on the current density and electromagnetic force. When the magnetic field and the transport current intervene together, the interaction between the transport current and the shielding current induced by the magnetic field significantly changes the distribution of the current density and the electromagnetic force, which further affects the interfacial stress and the delamination propagation path of the cohesive layer. The magnitudes of current density and electromagnetic force are proportional to the slopes of the variation curves of the transport current and magnetic field. Notably, in both scenarios, the interfacial shear delamination stress shows a clear tendency to concentrate at the edges of REBCO coated conductor, which is the primary factor driving interfacial delamination and crack propagation. Therefore, accurately measuring the shear delamination strength of REBCO coated conductors is highly significant for determining their operational limits under multi-field conditions.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 111001"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551710","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 characteristics of fractured methane hydrate-bearing sediments

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-02 DOI: 10.1016/j.engfracmech.2025.110986

Lei Wang , Wenqi Yu , Kai Zhang , Zhiheng Liu , Zhaoran Wu , Zaixing Liu , Shihui Ma , Yanghui Li

A large number of fractures have been discovered in natural gas hydrate (NGH) reservoirs on land and under the seabed worldwide, and the presence of these fractures may trigger deformation and instability of the reservoirs during NGH extraction. However, the specific impact of fractures on the mechanical properties of NGH reservoirs is still unknown at present. Based on these, this paper studies the strength characteristics of fractured hydrate-bearing sediments (FHBSs) and fracture-free hydrate-bearing sediments (FFHBSs) during shear processes under different effective stresses and hydrate saturations, and compares the stress–strain relationships, failure strengths, cohesion and internal friction angle between FHBSs and FFHBSs. The research indicates that under the same condition, the strength of FFHBSs is generally higher than that of FHBSs. In the absence of gas hydrates, the cohesion and internal friction angle of FHBSs are the same as those of FFHBSs. As the hydrate saturation increases (20% and 40%), the cohesion of FHBSs is lower than that of FFHBSs, while the internal friction angle of FHBSs is larger than that of FFHBSs. The research in this paper enhances the comprehension of the mechanical behavior of FHBSs and provides theoretical guidance for reducing the risk of geological disasters during NGH extraction.

{"title":"Strength characteristics of fractured methane hydrate-bearing sediments","authors":"Lei Wang , Wenqi Yu , Kai Zhang , Zhiheng Liu , Zhaoran Wu , Zaixing Liu , Shihui Ma , Yanghui Li","doi":"10.1016/j.engfracmech.2025.110986","DOIUrl":"10.1016/j.engfracmech.2025.110986","url":null,"abstract":"<div><div>A large number of fractures have been discovered in natural gas hydrate (NGH) reservoirs on land and under the seabed worldwide, and the presence of these fractures may trigger deformation and instability of the reservoirs during NGH extraction. However, the specific impact of fractures on the mechanical properties of NGH reservoirs is still unknown at present. Based on these, this paper studies the strength characteristics of fractured hydrate-bearing sediments (FHBSs) and fracture-free hydrate-bearing sediments (FFHBSs) during shear processes under different effective stresses and hydrate saturations, and compares the stress–strain relationships, failure strengths, cohesion and internal friction angle between FHBSs and FFHBSs. The research indicates that under the same condition, the strength of FFHBSs is generally higher than that of FHBSs. In the absence of gas hydrates, the cohesion and internal friction angle of FHBSs are the same as those of FFHBSs. As the hydrate saturation increases (20% and 40%), the cohesion of FHBSs is lower than that of FFHBSs, while the internal friction angle of FHBSs is larger than that of FFHBSs. The research in this paper enhances the comprehension of the mechanical behavior of FHBSs and provides theoretical guidance for reducing the risk of geological disasters during NGH extraction.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110986"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551709","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

Improvement of low-cycle fatigue properties in electron beam powder bed fusion processed Ti-6Al-4V alloy by laser shock peening

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-01 DOI: 10.1016/j.engfracmech.2025.110992

Chengyan Bai , Liang Lan , Lulu Jiang , Bo He , Yuzhou Li , Yongkang Zhang

In this study, laser shock peening (LSP) was applied to modify the surface microstructure and low-cycle fatigue (LCF) performance of electron beam powder bed fusion processed Ti-6Al-4V titanium alloy. The microstructure evolution, fatigue crack propagation, deformation behavior, and residual stress without and with LSP were compared to explore the role of gradient microstructure on the LCF behavior. The gradient microstructure induced by LSP is composed of nanograins and submicro-equiaxed grains. Moreover, the degree of work hardening near the surface of LSP-treated samples becomes higher after fatigue loading, which alleviates the cyclic softening behavior. The residual compressive stress within the surface layer experiences a 20 % reduction under high strain amplitude, yet there is still a uniformly distributed compressive residual stress layer at the deeper subsurface. A deeper gradient microstructure, work hardening layer, and compressive residual stress triggered via LSP can restrain the crack initiation and propagation, reduce the cyclic softening rate, and thus improve the LCF performance.

{"title":"Improvement of low-cycle fatigue properties in electron beam powder bed fusion processed Ti-6Al-4V alloy by laser shock peening","authors":"Chengyan Bai , Liang Lan , Lulu Jiang , Bo He , Yuzhou Li , Yongkang Zhang","doi":"10.1016/j.engfracmech.2025.110992","DOIUrl":"10.1016/j.engfracmech.2025.110992","url":null,"abstract":"<div><div>In this study, laser shock peening (LSP) was applied to modify the surface microstructure and low-cycle fatigue (LCF) performance of electron beam powder bed fusion processed Ti-6Al-4V titanium alloy. The microstructure evolution, fatigue crack propagation, deformation behavior, and residual stress without and with LSP were compared to explore the role of gradient microstructure on the LCF behavior. The gradient microstructure induced by LSP is composed of nanograins and submicro-equiaxed grains. Moreover, the degree of work hardening near the surface of LSP-treated samples becomes higher after fatigue loading, which alleviates the cyclic softening behavior. The residual compressive stress within the surface layer experiences a 20 % reduction under high strain amplitude, yet there is still a uniformly distributed compressive residual stress layer at the deeper subsurface. A deeper gradient microstructure, work hardening layer, and compressive residual stress triggered via LSP can restrain the crack initiation and propagation, reduce the cyclic softening rate, and thus improve the LCF performance.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110992"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551693","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

A configurational stress-based model to predict mixed-mode fracture of rock under different environments

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-01 DOI: 10.1016/j.engfracmech.2025.110941

Chao Wang, Jili Feng

This paper investigates mixed-mode fracture in rock under different environments. The principle of energy conservation provides a clear physical interpretation of the configurational stress tensor, revealing that its components represent the change in total energy induced by material element translation. The Mohr–Coulomb yield function is employed to define the boundary of crack-tip plastic zone. A novel configurational stress-based Mohr–Coulomb yield function is proposed, enhancing the accuracy of plastic zone size and shape assessment. Additionally, a fracture criterion is developed based on the local properties of the crack-tip plastic zone, and then the time factor of Burgers body is incorporated to elucidate the rheological fracture properties of rock. Utilizing this fracture criterion, the impacts of drying–wetting cycles, heating–cooling cycles, thermal treatment and chemical corrosion on rock fracture are investigated. The proposed fracture criterion accurately predicts crack initiation angles and fracture loads, aligning with predictions of the maximum tensile stress criterion and experiments. It is found that the fracture loads decrease with the number of drying–wetting and heating–cooling cycles. The crack-tip plastic zone is observed to expand over time, leading to a reduction in the fracture loading envelope. Furthermore, the fracture loading envelope generally decreases with increasing thermal treatment temperature, and the mixed-mode fracture resistance is the minimum in acidic environments. This paper provides a valuable reference for addressing the challenges of rock mixed-mode fracture under different environments.

{"title":"A configurational stress-based model to predict mixed-mode fracture of rock under different environments","authors":"Chao Wang, Jili Feng","doi":"10.1016/j.engfracmech.2025.110941","DOIUrl":"10.1016/j.engfracmech.2025.110941","url":null,"abstract":"<div><div>This paper investigates mixed-mode fracture in rock under different environments. The principle of energy conservation provides a clear physical interpretation of the configurational stress tensor, revealing that its components represent the change in total energy induced by material element translation. The Mohr–Coulomb yield function is employed to define the boundary of crack-tip plastic zone. A novel configurational stress-based Mohr–Coulomb yield function is proposed, enhancing the accuracy of plastic zone size and shape assessment. Additionally, a fracture criterion is developed based on the local properties of the crack-tip plastic zone, and then the time factor of Burgers body is incorporated to elucidate the rheological fracture properties of rock. Utilizing this fracture criterion, the impacts of drying–wetting cycles, heating–cooling cycles, thermal treatment and chemical corrosion on rock fracture are investigated. The proposed fracture criterion accurately predicts crack initiation angles and fracture loads, aligning with predictions of the maximum tensile stress criterion and experiments. It is found that the fracture loads decrease with the number of drying–wetting and heating–cooling cycles. The crack-tip plastic zone is observed to expand over time, leading to a reduction in the fracture loading envelope. Furthermore, the fracture loading envelope generally decreases with increasing thermal treatment temperature, and the mixed-mode fracture resistance is the minimum in acidic environments. This paper provides a valuable reference for addressing the challenges of rock mixed-mode fracture under different environments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110941"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551725","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

Influence of crystal orientation on mechanical properties and stress distribution in monocrystalline sapphire

IF 4.7 2区工程技术 Q1 MECHANICS

Engineering Fracture Mechanics

Pub Date : 2025-03-01 DOI: 10.1016/j.engfracmech.2025.110996

Xingyu Wang, Wen Zheng, Huixin Xing, Xiaoyu Bao, Qingliang Zhao, Yinchuan Piao

The deformation behavior of monocrystalline materials is intricately linked to the anisotropic nature of their mechanical characteristics, slip motion, and cleavage motion. To systematically analyze the deformation and fracture behavior of monocrystalline sapphire and address existing shortcomings in the detection of its mechanical properties, we conducted a series of nanoindentation experiments and analyses across various crystal orientations of sapphire. A model for the stress field was developed by considering slip motion, cleavage fracture, and the mechanical properties of monocrystalline sapphire. Our findings indicate that cracks propagate in specific directions and exhibit anisotropic characteristics. The hardness and elastic modulus of sapphire across distinct planes follow the order: R < N < C < M < A, while the fracture toughness exhibits the opposite trend. Results concerning the stress field distribution, Schmid factor, and cleavage factor reveal that the M and A planes are more susceptible to brittle cracking and cleavage fracture, whereas the R and N planes are more likely to undergo plastic deformation.

{"title":"Influence of crystal orientation on mechanical properties and stress distribution in monocrystalline sapphire","authors":"Xingyu Wang, Wen Zheng, Huixin Xing, Xiaoyu Bao, Qingliang Zhao, Yinchuan Piao","doi":"10.1016/j.engfracmech.2025.110996","DOIUrl":"10.1016/j.engfracmech.2025.110996","url":null,"abstract":"<div><div>The deformation behavior of monocrystalline materials is intricately linked to the anisotropic nature of their mechanical characteristics, slip motion, and cleavage motion. To systematically analyze the deformation and fracture behavior of monocrystalline sapphire and address existing shortcomings in the detection of its mechanical properties, we conducted a series of nanoindentation experiments and analyses across various crystal orientations of sapphire. A model for the stress field was developed by considering slip motion, cleavage fracture, and the mechanical properties of monocrystalline sapphire. Our findings indicate that cracks propagate in specific directions and exhibit anisotropic characteristics. The hardness and elastic modulus of sapphire across distinct planes follow the order: R < N < C < M < A, while the fracture toughness exhibits the opposite trend. Results concerning the stress field distribution, Schmid factor, and cleavage factor reveal that the M and A planes are more susceptible to brittle cracking and cleavage fracture, whereas the R and N planes are more likely to undergo plastic deformation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110996"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551723","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