Pub Date : 2025-02-14DOI: 10.1177/10567895251319408
George Z Voyiadjis, Peter I Kattan
A mathematical formulation incorporating the relationship between the damage tensor, healing tensor, and fabric tensors is presented. This formulation provides for a direct link between the subjects of Damage and Healing Mechanics using Fabric Tensors. A new damage-healing tensor is introduced that is based on the fabric of the material. This new tensor is pivotal in characterizing the micro-structure of the material, especially the distributions of micro-cracks and other micro defects. It is noted that the theory applies to linear elastic materials but can be generalized to other constitutive models incorporating inelastic behavior. As examples, the authors solve three cases, namely those of plane stress, plane strain, and isotropic elasticity. The case of plane stress assumes plane damage and plane healing as will be illustrated in the equations. Similarly, the case of plane strain is also illustrated. The case of isotropic elasticity assumes the presence of isotropic damage and isotropic healing. As an illustration, a numerical example is shown for a certain micro-crack distribution. Finally, experimental results are shown to illustrate the relationship between the fabric tensor parameters and the components of the damage and healing tensors. Finally, the evolution of damage and healing are discussed based on sound thermodynamic principles.
{"title":"Use of fabric tensors in damage and healing mechanics of materials","authors":"George Z Voyiadjis, Peter I Kattan","doi":"10.1177/10567895251319408","DOIUrl":"https://doi.org/10.1177/10567895251319408","url":null,"abstract":"A mathematical formulation incorporating the relationship between the damage tensor, healing tensor, and fabric tensors is presented. This formulation provides for a direct link between the subjects of Damage and Healing Mechanics using Fabric Tensors. A new damage-healing tensor is introduced that is based on the fabric of the material. This new tensor is pivotal in characterizing the micro-structure of the material, especially the distributions of micro-cracks and other micro defects. It is noted that the theory applies to linear elastic materials but can be generalized to other constitutive models incorporating inelastic behavior. As examples, the authors solve three cases, namely those of plane stress, plane strain, and isotropic elasticity. The case of plane stress assumes plane damage and plane healing as will be illustrated in the equations. Similarly, the case of plane strain is also illustrated. The case of isotropic elasticity assumes the presence of isotropic damage and isotropic healing. As an illustration, a numerical example is shown for a certain micro-crack distribution. Finally, experimental results are shown to illustrate the relationship between the fabric tensor parameters and the components of the damage and healing tensors. Finally, the evolution of damage and healing are discussed based on sound thermodynamic principles.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"10 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417739","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}
Pub Date : 2025-02-10DOI: 10.1177/10567895241305592
Claudio Findeisen, Jörg Hohe
Due to crack bridging effects, ceramic matrix composites (CMCs) have outstanding properties that combine a quasi-ductile material behaviour with the high-temperature properties of ceramics. Combined with their high specific strength, this makes them perfectly suitable for high temperature safety relevant components. In view of the design process of CMC components elaborated continuum damage models are required that most importantly consider their anisotropy and damage deactivation effects in a mechanically and mathematically consistent manner. With respect to their damage effect, most of the existing anisotropic models fail with regard to the damage growth criterion leading to the unphysical effect of an increasing stiffness due to damage. Motivated by the modelling process of initially anisotropic composite materials like CMCs, this paper presents the systematic formulation and validation of a mechanically consistent damage effect model together with crack closure effects.
{"title":"Mechanically consistent continuum damage model for anisotropic composites including damage deactivation","authors":"Claudio Findeisen, Jörg Hohe","doi":"10.1177/10567895241305592","DOIUrl":"https://doi.org/10.1177/10567895241305592","url":null,"abstract":"Due to crack bridging effects, ceramic matrix composites (CMCs) have outstanding properties that combine a quasi-ductile material behaviour with the high-temperature properties of ceramics. Combined with their high specific strength, this makes them perfectly suitable for high temperature safety relevant components. In view of the design process of CMC components elaborated continuum damage models are required that most importantly consider their anisotropy and damage deactivation effects in a mechanically and mathematically consistent manner. With respect to their damage effect, most of the existing anisotropic models fail with regard to the damage growth criterion leading to the unphysical effect of an increasing stiffness due to damage. Motivated by the modelling process of initially anisotropic composite materials like CMCs, this paper presents the systematic formulation and validation of a mechanically consistent damage effect model together with crack closure effects.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"160 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385607","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}
Pub Date : 2025-02-07DOI: 10.1177/10567895251314676
Jun Li, Xiaoman Feng, Junling Hou, Yaohua Liu, Binglei Wang
The paper investigates the issue of damage in interfacial materials using M-integral. It demonstrates that the integration path of M-integral can cross the material interface. The numerical calculation of M-integral is realized by using domain integral method. The accuracy of the model was verified using analytical solutions. The factors affecting the M-integral of the interfacial material are explored with the help of finite elements. The study explores the effects of elastic modulus ratio, defects, and load on the M-integral, and proposes an equivalent damage calibration method based on the M-integral. The results suggest that once the elastic modulus ratio exceeds a certain threshold, it is no longer the primary factor influencing the M-integral. The equivalent defect for elastic problems is linked to the original defect configuration and elastic modulus ratio, and is independent of the external load. This study is important for calibrating damage levels of interfacial materials, designing for damage tolerance in structures, and assessing integrity.
{"title":"Damage evaluation of interfacial materials based on M-integral","authors":"Jun Li, Xiaoman Feng, Junling Hou, Yaohua Liu, Binglei Wang","doi":"10.1177/10567895251314676","DOIUrl":"https://doi.org/10.1177/10567895251314676","url":null,"abstract":"The paper investigates the issue of damage in interfacial materials using M-integral. It demonstrates that the integration path of M-integral can cross the material interface. The numerical calculation of M-integral is realized by using domain integral method. The accuracy of the model was verified using analytical solutions. The factors affecting the M-integral of the interfacial material are explored with the help of finite elements. The study explores the effects of elastic modulus ratio, defects, and load on the M-integral, and proposes an equivalent damage calibration method based on the M-integral. The results suggest that once the elastic modulus ratio exceeds a certain threshold, it is no longer the primary factor influencing the M-integral. The equivalent defect for elastic problems is linked to the original defect configuration and elastic modulus ratio, and is independent of the external load. This study is important for calibrating damage levels of interfacial materials, designing for damage tolerance in structures, and assessing integrity.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"1 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258429","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}
Pub Date : 2025-01-21DOI: 10.1177/10567895241313243
Qiuping Li, Jie Liu, Hao Wang
To effectively prevent dynamic gas disasters, the adding vertical and unloading radial stress were investigated in laboratory and numerical simulation experiments. The objective about the research was to ascertain how various gas pressures and loading rates affected permeability and damage deformation. The results conclude that shear failure predominates in gassy coal, a rise in loading rate causes the permeability to mutate more slowly, and the plastic strain gradually decreases at the yield, peak, and post-peak stable points in gassy coal. As well, a rise in gas pressure causes an earlier transition from compression to expansion state of specimens, enhances permeability, and rises the plastic strain at specified points. Furthermore, the study focuses on the meso-scale failure and permeability characteristics. During failure, the seepage channel within the coal body gradually transitions from a vertical orientation to irregular deformation. In addition, a damage model is formulated centered around energy consumption, demonstrating that damage evolution curves exhibit an ‘ S’ shape with vertical strain. Meanwhile, higher axial loading rates delay the onset of unstable crack propagation, but raising gas pressure quickens the pace of damage to specimens. The conclusions of this research hold significant practical implications for mitigating coal-rock gas dynamic disasters.
{"title":"Damage and permeability of gassy coal in loading – Unloading path","authors":"Qiuping Li, Jie Liu, Hao Wang","doi":"10.1177/10567895241313243","DOIUrl":"https://doi.org/10.1177/10567895241313243","url":null,"abstract":"To effectively prevent dynamic gas disasters, the adding vertical and unloading radial stress were investigated in laboratory and numerical simulation experiments. The objective about the research was to ascertain how various gas pressures and loading rates affected permeability and damage deformation. The results conclude that shear failure predominates in gassy coal, a rise in loading rate causes the permeability to mutate more slowly, and the plastic strain gradually decreases at the yield, peak, and post-peak stable points in gassy coal. As well, a rise in gas pressure causes an earlier transition from compression to expansion state of specimens, enhances permeability, and rises the plastic strain at specified points. Furthermore, the study focuses on the meso-scale failure and permeability characteristics. During failure, the seepage channel within the coal body gradually transitions from a vertical orientation to irregular deformation. In addition, a damage model is formulated centered around energy consumption, demonstrating that damage evolution curves exhibit an ‘ S’ shape with vertical strain. Meanwhile, higher axial loading rates delay the onset of unstable crack propagation, but raising gas pressure quickens the pace of damage to specimens. The conclusions of this research hold significant practical implications for mitigating coal-rock gas dynamic disasters.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"46 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992031","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}
In the highway construction of the southwestern Transverse Mountain area of China, mass mudstone engineering disasters have occurred, primarily attributed to engineering disturbances and water-rock interaction. Engineering disturbances commonly lead to varying degrees of pre-peak damage. To elucidate the evolutionary laws of strength in pre-peak damaged mudstone, we first defined the pre-peak damage variable ( Da) for mudstone, and through triaxial loading and unloading tests, obtained the mechanical characteristics of pre-peak damaged mudstone, analyzing its brittle properties from an energy perspective. Subsequently, through scanning electron microscopy tests, we analyzed the microstructural features to reveal the failure mechanism. Finally, the damage ratio strength theory (DR) was introduced to characterize the strength of the mudstone and validate the suitability of the DR. The results demonstrate that: (1) Mudstone with pre-peak damage exhibits a significant weakening effect due to water-rock interaction, with a maximum reduction in peak strength of approximately 28%. Compared to the loading stress path (LSP), the overall strength of the mudstone is lower under the unloading stress path (ULSP), and the deformation modulus decreases more significantly with Da under the ULSP. (2) Both the Daand confining pressure contribute to a decrease in the brittleness index of the mudstone. Under the ULSP, the mudstone is more prone to brittle failure. (3) The development of micro-cracks in pre-peak damaged mudstone makes it more susceptible to water infiltration, exacerbating the deteriorating effect of water-rock interaction, thus affecting its mechanical properties. (4) The DR can effectively characterize the strength of pre-peak damaged mudstone. The Damage Ratio (ν D,c) of mudstone under the LSP is in the range of 1.07∼1.50, and under the ULSP is in the range of 1.11∼1.52. The ν D,c under the LSP is smaller than under the ULSP, decreases with the Da, and exhibits plastic deformation, indicating that the DR can simultaneously characterize the strength and brittleness of the mudstone. The research results can provide guidance for the design parameters and disaster prevention of disturbed mudstone engineering.
{"title":"Study on mechanical properties and strength criterion of mudstone under loading and unloading considering pre-peak damage","authors":"Hui Qin, Hua Tang, Xiaotao Yin, Xu Cheng, Shengping Tang","doi":"10.1177/10567895241297327","DOIUrl":"https://doi.org/10.1177/10567895241297327","url":null,"abstract":"In the highway construction of the southwestern Transverse Mountain area of China, mass mudstone engineering disasters have occurred, primarily attributed to engineering disturbances and water-rock interaction. Engineering disturbances commonly lead to varying degrees of pre-peak damage. To elucidate the evolutionary laws of strength in pre-peak damaged mudstone, we first defined the pre-peak damage variable ( D<jats:sub>a</jats:sub>) for mudstone, and through triaxial loading and unloading tests, obtained the mechanical characteristics of pre-peak damaged mudstone, analyzing its brittle properties from an energy perspective. Subsequently, through scanning electron microscopy tests, we analyzed the microstructural features to reveal the failure mechanism. Finally, the damage ratio strength theory (DR) was introduced to characterize the strength of the mudstone and validate the suitability of the DR. The results demonstrate that: (1) Mudstone with pre-peak damage exhibits a significant weakening effect due to water-rock interaction, with a maximum reduction in peak strength of approximately 28%. Compared to the loading stress path (LSP), the overall strength of the mudstone is lower under the unloading stress path (ULSP), and the deformation modulus decreases more significantly with D<jats:sub>a</jats:sub> under the ULSP. (2) Both the D<jats:sub>a</jats:sub>and confining pressure contribute to a decrease in the brittleness index of the mudstone. Under the ULSP, the mudstone is more prone to brittle failure. (3) The development of micro-cracks in pre-peak damaged mudstone makes it more susceptible to water infiltration, exacerbating the deteriorating effect of water-rock interaction, thus affecting its mechanical properties. (4) The DR can effectively characterize the strength of pre-peak damaged mudstone. The Damage Ratio (ν <jats:sub>D,c</jats:sub>) of mudstone under the LSP is in the range of 1.07∼1.50, and under the ULSP is in the range of 1.11∼1.52. The ν <jats:sub>D,c</jats:sub> under the LSP is smaller than under the ULSP, decreases with the D<jats:sub>a</jats:sub>, and exhibits plastic deformation, indicating that the DR can simultaneously characterize the strength and brittleness of the mudstone. The research results can provide guidance for the design parameters and disaster prevention of disturbed mudstone engineering.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"12 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936733","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}
Pub Date : 2025-01-06DOI: 10.1177/10567895241297301
Feker Mnif, Guesmi Youssef, Rémy Larouche, Hatem Mrad, Sébastien Morin, Robert Poirier, Ahmed Koubaa
In the wood panel industry, metallic contaminants raise significant concerns, especially regarding the press plate's surface integrity, which requires a thorough inspection. This study investigated the effect of metallic contaminants on press plate damage and evaluated the use of infrared thermography (IRT) and infrared (IR) spectroscopy as non-destructive testing (NDT) methods for detecting these contaminants in wood panel manufacturing. Metallic contaminants embedded within lab-scale wood panels demonstrated their impact on the surface quality of both the press plate and the resulting panels. Moreover, confocal laser microscope analysis revealed that the surface roughness of the press plate surface was influenced by the specific alloy composition of contaminants, with steel and chromium contaminants exhibiting the more severe damage (e.g., mean roughness values of 59,80 and 84,64 μm, respectively). Thermography images exhibited the efficacy of IRT in detecting contaminants close to the surface of thin panels. However, an advanced camera is recommended for thicker panels and deeper contaminants to obtain a more accurate inspection. The Fourier-transform infrared spectroscopy (FTIR) evaluation revealed the presence of the metal-oxygen vibration band at approximately 668 cm−1 across all alloy compositions, suggesting its potential as a reliable reference for detecting metallic contaminants.
{"title":"Metallic contaminants in wood panel production process: Evaluating press plate damage and detecting potential using IR thermography and spectroscopy","authors":"Feker Mnif, Guesmi Youssef, Rémy Larouche, Hatem Mrad, Sébastien Morin, Robert Poirier, Ahmed Koubaa","doi":"10.1177/10567895241297301","DOIUrl":"https://doi.org/10.1177/10567895241297301","url":null,"abstract":"In the wood panel industry, metallic contaminants raise significant concerns, especially regarding the press plate's surface integrity, which requires a thorough inspection. This study investigated the effect of metallic contaminants on press plate damage and evaluated the use of infrared thermography (IRT) and infrared (IR) spectroscopy as non-destructive testing (NDT) methods for detecting these contaminants in wood panel manufacturing. Metallic contaminants embedded within lab-scale wood panels demonstrated their impact on the surface quality of both the press plate and the resulting panels. Moreover, confocal laser microscope analysis revealed that the surface roughness of the press plate surface was influenced by the specific alloy composition of contaminants, with steel and chromium contaminants exhibiting the more severe damage (e.g., mean roughness values of 59,80 and 84,64 μm, respectively). Thermography images exhibited the efficacy of IRT in detecting contaminants close to the surface of thin panels. However, an advanced camera is recommended for thicker panels and deeper contaminants to obtain a more accurate inspection. The Fourier-transform infrared spectroscopy (FTIR) evaluation revealed the presence of the metal-oxygen vibration band at approximately 668 cm<jats:sup>−1</jats:sup> across all alloy compositions, suggesting its potential as a reliable reference for detecting metallic contaminants.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"13 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935157","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}
Pub Date : 2024-12-30DOI: 10.1177/10567895241302543
Yamato Hoshikawa, Kazuki Ryuzono, Sota Onodera, Yoshiaki Kawagoe, Tomonaga Okabe
Fiber-reinforced composites are essential in the aerospace industry, highlighting the need for an in-depth understanding of their durability. This study introduces a novel approach that integrates viscoelasticity and damage evolution based on continuum damage mechanics, employing finite element analysis. The method utilizes an anisotropic viscoelastic constitutive law to examine creep behavior under constant stress, decomposing stresses into equilibrium and non-equilibrium components. Moreover, it integrates a transverse crack damage variable associated with crack density. After solving stiffness equations, a detailed analysis of transverse crack propagation is conducted. This technique was applied to creep tests on carbon fiber-reinforced plastics and 3D woven ceramic matrix composites, resulting in strain and crack density profiles. The numerical simulations successfully reproduced experimental outcomes. The developed method offers a comprehensive tool for analyzing transverse crack propagation under viscoelastic creep conditions through finite element analysis, significantly enhancing design considerations by incorporating aspects of long-term durability.
{"title":"Finite element modeling of viscoelastic creep behavior and transverse cracking in fiber-reinforced composite materials","authors":"Yamato Hoshikawa, Kazuki Ryuzono, Sota Onodera, Yoshiaki Kawagoe, Tomonaga Okabe","doi":"10.1177/10567895241302543","DOIUrl":"https://doi.org/10.1177/10567895241302543","url":null,"abstract":"Fiber-reinforced composites are essential in the aerospace industry, highlighting the need for an in-depth understanding of their durability. This study introduces a novel approach that integrates viscoelasticity and damage evolution based on continuum damage mechanics, employing finite element analysis. The method utilizes an anisotropic viscoelastic constitutive law to examine creep behavior under constant stress, decomposing stresses into equilibrium and non-equilibrium components. Moreover, it integrates a transverse crack damage variable associated with crack density. After solving stiffness equations, a detailed analysis of transverse crack propagation is conducted. This technique was applied to creep tests on carbon fiber-reinforced plastics and 3D woven ceramic matrix composites, resulting in strain and crack density profiles. The numerical simulations successfully reproduced experimental outcomes. The developed method offers a comprehensive tool for analyzing transverse crack propagation under viscoelastic creep conditions through finite element analysis, significantly enhancing design considerations by incorporating aspects of long-term durability.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"35 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142904782","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}
This study focused on understanding the fatigue response of anisotropic spherulitic polymers by employing a multiscale microscopic modeling approach. The crystal plasticity model together with the Arruda-Boyce model were used to describe the mechanical response of crystalline phase and amorphous. The fatigue behaviors and crack initiation were captured by Fatemi-Socie multiaxial criterion and continuous damage theory under multiaxial and non-proportional loading conditions. The sheaf-like structure of spherulitic polymers was considered to shed light on the anisotropic nature of fatigue failure. The results highlight the role of features of sheaf structure, e.g., initiation orientation, on the fatigue performance of spherulitic polymers, which have not been reported. The localized degradation of mechanical properties and the accumulation of fatigue damage were systematically discussed with various loading patterns. This study provided an in-depth understanding of potential fatigue mechanisms, offering robust support for fatigue resistance design in engineering applications.
{"title":"Micromechanical analysis of spherulitic polymers in multiaxial and non-proportional fatigue crack nucleation","authors":"Chenxu Jiang, Jia Zhou, Jiaxin Cui, Changqing Miao","doi":"10.1177/10567895241302873","DOIUrl":"https://doi.org/10.1177/10567895241302873","url":null,"abstract":"This study focused on understanding the fatigue response of anisotropic spherulitic polymers by employing a multiscale microscopic modeling approach. The crystal plasticity model together with the Arruda-Boyce model were used to describe the mechanical response of crystalline phase and amorphous. The fatigue behaviors and crack initiation were captured by Fatemi-Socie multiaxial criterion and continuous damage theory under multiaxial and non-proportional loading conditions. The sheaf-like structure of spherulitic polymers was considered to shed light on the anisotropic nature of fatigue failure. The results highlight the role of features of sheaf structure, e.g., initiation orientation, on the fatigue performance of spherulitic polymers, which have not been reported. The localized degradation of mechanical properties and the accumulation of fatigue damage were systematically discussed with various loading patterns. This study provided an in-depth understanding of potential fatigue mechanisms, offering robust support for fatigue resistance design in engineering applications.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"12 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142887747","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}
This paper presents a novel three-phase damage model for the prediction of the post-peak responses of composite materials, such as recycled aggregate concrete (RAC). The proposed damage model is based on composite damage mechanics and is composed of three phases: cement paste, interface transition zone (ITZ), and aggregate. All phases are assumed to be linearly elastic and isotropic materials. The aggregate is supposed to be the undamaged material, while the cement paste and ITZ are considered the damaged materials. Three different composite damage models, namely Voigt (parallel), Reuss (serial), and the proposed generalized self-consistent (spherical), represent the damage growth in the composite materials. The Voigt parallel model is employed to address the upper bound of post-peak stiffness and stress, while the Reuss serial model represents the lower bound. To investigate the softening phenomenon after the post-peak state, both linear and exponential functions are used to describe the stress-strain curve in this state. Two numerical simulations are provided to examine the stress degradation in the softening state. Both simulations reveal that the post-peak stress degrades with increasing damage parameters and ITZ thickness. Therefore, both damage and ITZ’s thickness are significant factors for analyzing the post-peak responses of RAC.
{"title":"Three-phase damage model based on composite mechanics for post-peak analysis of recycled aggregate concrete","authors":"Worathep Sae-Long, Nattapong Damrongwiriyanupap, Suchart Limkatanyu, Yunping Xi, Tanakorn Phoo-ngernkham, Piti Sukontasukkul, Suraparb Keawsawasvong","doi":"10.1177/10567895241303221","DOIUrl":"https://doi.org/10.1177/10567895241303221","url":null,"abstract":"This paper presents a novel three-phase damage model for the prediction of the post-peak responses of composite materials, such as recycled aggregate concrete (RAC). The proposed damage model is based on composite damage mechanics and is composed of three phases: cement paste, interface transition zone (ITZ), and aggregate. All phases are assumed to be linearly elastic and isotropic materials. The aggregate is supposed to be the undamaged material, while the cement paste and ITZ are considered the damaged materials. Three different composite damage models, namely Voigt (parallel), Reuss (serial), and the proposed generalized self-consistent (spherical), represent the damage growth in the composite materials. The Voigt parallel model is employed to address the upper bound of post-peak stiffness and stress, while the Reuss serial model represents the lower bound. To investigate the softening phenomenon after the post-peak state, both linear and exponential functions are used to describe the stress-strain curve in this state. Two numerical simulations are provided to examine the stress degradation in the softening state. Both simulations reveal that the post-peak stress degrades with increasing damage parameters and ITZ thickness. Therefore, both damage and ITZ’s thickness are significant factors for analyzing the post-peak responses of RAC.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"32 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867093","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}
Pub Date : 2024-12-09DOI: 10.1177/10567895241303157
Zhibiao Guo, Jingwei Gao, Jinglin You, Dongshan Yang
To comprehensively investigate the influence of water content on the mechanical and crack propagation characteristics of coal rock assemblage (CRA) with a rough interface, uniaxial compression tests were conducted on specimens with varying water content. Nuclear magnetic resonance (NMR) and acoustic emission (AE) techniques were employed to monitor the water content and AE signals throughout the experiment. The physical and mechanical properties, as well as the extent of crack development and acoustic emission (AE) parameters, were comprehensively investigated under conditions of water erosion. The results demonstrate that a rough interface contributes to an enhancement in the compressive strength of the composite material. Moreover, the moisture content exerts a significant influence on various aspects of the composite specimen, including its compressive strength, time b value, crack development, and crack propagation. With the increase in water content, the initial single slope shear failure of the composite specimen gradually transitions into a multi-section shear failure mechanism. Under the influence of water-rock interaction, sandstone within the formation undergoes a metamorphosis from a densely cemented structure to an irregular honeycomb-like configuration. This transformative process engenders novel porosity and fractures, ultimately compromising the rock’s mechanical strength. The analysis focuses on the relationship between the AE parameter b and uniaxial stress and water content, with emphasis on its relevance to damage theory. A damage model based on water immersion rate was established to elucidate the correlation between damage variables and water content. This was achieved by considering the characteristics of water-rock coupling AE and constructing a structural model of the water absorption process in different pore throats, thereby providing valuable insights for stability design and evaluation of roadway rock masses.
{"title":"Influence of water saturation on mechanical characteristics and fracture evolution of coal rock assemblage with rough interfaces","authors":"Zhibiao Guo, Jingwei Gao, Jinglin You, Dongshan Yang","doi":"10.1177/10567895241303157","DOIUrl":"https://doi.org/10.1177/10567895241303157","url":null,"abstract":"To comprehensively investigate the influence of water content on the mechanical and crack propagation characteristics of coal rock assemblage (CRA) with a rough interface, uniaxial compression tests were conducted on specimens with varying water content. Nuclear magnetic resonance (NMR) and acoustic emission (AE) techniques were employed to monitor the water content and AE signals throughout the experiment. The physical and mechanical properties, as well as the extent of crack development and acoustic emission (AE) parameters, were comprehensively investigated under conditions of water erosion. The results demonstrate that a rough interface contributes to an enhancement in the compressive strength of the composite material. Moreover, the moisture content exerts a significant influence on various aspects of the composite specimen, including its compressive strength, time b value, crack development, and crack propagation. With the increase in water content, the initial single slope shear failure of the composite specimen gradually transitions into a multi-section shear failure mechanism. Under the influence of water-rock interaction, sandstone within the formation undergoes a metamorphosis from a densely cemented structure to an irregular honeycomb-like configuration. This transformative process engenders novel porosity and fractures, ultimately compromising the rock’s mechanical strength. The analysis focuses on the relationship between the AE parameter b and uniaxial stress and water content, with emphasis on its relevance to damage theory. A damage model based on water immersion rate was established to elucidate the correlation between damage variables and water content. This was achieved by considering the characteristics of water-rock coupling AE and constructing a structural model of the water absorption process in different pore throats, thereby providing valuable insights for stability design and evaluation of roadway rock masses.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"28 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797124","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}
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