Pub Date : 2025-08-18DOI: 10.1177/10567895251358294
Louise Olsen-Kettle, Sanjib Mondal, Hugo Walsh, Bradley Talbot, Osamah Obayes, Jessey Lee
Concrete cone (or breakout) failure mode is the dominant failure for cast-in headed anchors under tension in mature brittle concrete, however, other failure modes such as plug failure has been found experimentally to dominate in early age concrete. Design codes generally assume concrete cone failure and do not cover plug failure. A new model for concrete at early ages is proposed based on continuum damage mechanics which can model both failure modes for cast-in headed anchors in early age concrete. The new damage model combines a modified power law for the onset of damage, an exponential softening law for the post-failure softening stage, and an additional modified power law to reproduce the final stages of fracture. The combined damage law is calibrated with three experimental tests for concrete at two different ages (43 hours and 14 days): uniaxial compression, Brazilian splitting tensile and wedge splitting tests. The new models are applied to investigate anchor pull-out failure to demonstrate that both cone and plug failure modes are produced depending on concrete age. Simulations using the combined damage evolution laws gave the lowest average percent error over the mechanical properties measured in the four tests, when compared with existing damage evolution laws.
{"title":"Analysis of new damage evolution models for early age concrete","authors":"Louise Olsen-Kettle, Sanjib Mondal, Hugo Walsh, Bradley Talbot, Osamah Obayes, Jessey Lee","doi":"10.1177/10567895251358294","DOIUrl":"https://doi.org/10.1177/10567895251358294","url":null,"abstract":"Concrete cone (or breakout) failure mode is the dominant failure for cast-in headed anchors under tension in mature brittle concrete, however, other failure modes such as plug failure has been found experimentally to dominate in early age concrete. Design codes generally assume concrete cone failure and do not cover plug failure. A new model for concrete at early ages is proposed based on continuum damage mechanics which can model both failure modes for cast-in headed anchors in early age concrete. The new damage model combines a modified power law for the onset of damage, an exponential softening law for the post-failure softening stage, and an additional modified power law to reproduce the final stages of fracture. The combined damage law is calibrated with three experimental tests for concrete at two different ages (43 hours and 14 days): uniaxial compression, Brazilian splitting tensile and wedge splitting tests. The new models are applied to investigate anchor pull-out failure to demonstrate that both cone and plug failure modes are produced depending on concrete age. Simulations using the combined damage evolution laws gave the lowest average percent error over the mechanical properties measured in the four tests, when compared with existing damage evolution laws.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"13 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144901875","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 : 2025-07-30DOI: 10.1177/10567895251357959
Jiaming Yuan, Dongdong Ma, Chao Li
Two modification approaches, namely vacuum heating and cement precoating, were applied to optimize the bulk hardening and surface treatment of rubber particles. The physicochemical characteristics of vacuum-heated modified rubber underwent comprehensive evaluation through rubber hardness testing, water contact angle assessments, and Fourier transform infrared spectroscopy. Unconfined compressive strength (UCS) tests combined with digital image correlation techniques were utilized to evaluate the strength improvement and damage evolution mechanism in modified rubber cement stabilized soil (RCS) specimens, while scanning electron microscopy was used to further characterize the microstructural failure mechanisms of modified RCS. The effectiveness of both methods was validated through significance analysis and nonlinear surface fitting of RCS strength data under varying modification parameters. Experimental results revealed that vacuum heating elevated rubber hardness by 34.6% and decreased water contact angle by 16.1° relative to untreated controls, significantly enhancing the UCS of RCS. The vacuum heating method could improve the cohesive properties and structural continuity of specimens, whereas cement precoated samples achieved strength gains without sacrificing material toughness. Both of the above two methods successfully facilitated rubber particle integration within the cement-stabilized soil matrix.
{"title":"Study on mechanical properties and damage evolution of modified rubberized cement stabilized soil","authors":"Jiaming Yuan, Dongdong Ma, Chao Li","doi":"10.1177/10567895251357959","DOIUrl":"https://doi.org/10.1177/10567895251357959","url":null,"abstract":"Two modification approaches, namely vacuum heating and cement precoating, were applied to optimize the bulk hardening and surface treatment of rubber particles. The physicochemical characteristics of vacuum-heated modified rubber underwent comprehensive evaluation through rubber hardness testing, water contact angle assessments, and Fourier transform infrared spectroscopy. Unconfined compressive strength (UCS) tests combined with digital image correlation techniques were utilized to evaluate the strength improvement and damage evolution mechanism in modified rubber cement stabilized soil (RCS) specimens, while scanning electron microscopy was used to further characterize the microstructural failure mechanisms of modified RCS. The effectiveness of both methods was validated through significance analysis and nonlinear surface fitting of RCS strength data under varying modification parameters. Experimental results revealed that vacuum heating elevated rubber hardness by 34.6% and decreased water contact angle by 16.1° relative to untreated controls, significantly enhancing the UCS of RCS. The vacuum heating method could improve the cohesive properties and structural continuity of specimens, whereas cement precoated samples achieved strength gains without sacrificing material toughness. Both of the above two methods successfully facilitated rubber particle integration within the cement-stabilized soil matrix.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"137 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747363","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 : 2025-07-30DOI: 10.1177/10567895251358292
Juntao Wang, Li'an Shen, Xue Luo, Yuqing Zhang
Research on bituminous material fatigue has traditionally focused on tensile or shear damage of bitumen and asphalt mixtures, neglecting the critical bitumen–aggregate interfaces where microcracks initiate. Addressing this gap, the pull-off fatigue crack (POF-C) model was built to predict crack propagation at these interfaces under pull-off cyclic loading. The model, based on continuum damage mechanics principles, integrates force equilibrium and dissipated strain energy equilibrium. Pull-off fatigue tests were conducted on interfaces using limestone, tuff, and basalt aggregates, with #70 matrix bitumen and styrene–butadiene–styrene copolymer-modified bitumen, at temperatures of 15°C and 20°C, and with bitumen film thicknesses ranging from 0.2 mm to 0.8 mm. Dynamic modulus and phase angle data informed the model inputs. Predicted crack sizes closely matched measured results on fractured surfaces, demonstrating less than 2% prediction error. Scanning electron microscope tests confirmed the model's validity, showing numerous circular mesh depressions on fracture surfaces. The POF-C model accurately forecasts POF-C lengths across varied conditions, revealing three distinct stages of crack propagation: a rapid growth (∼0.025 mm/cycle), a stable expansion stage (<0.025 mm/cycle), and a slow fatigue stage (∼0 mm/cycle). The fatigue mechanism involves the development of microdamage into microcracks, their nucleation and aggregation, and macrocrack throughout the entire bitumen–aggregate interface.
{"title":"Mechanistic modeling and pull-off experimental validations of fatigue damage at bitumen–aggregate interfaces","authors":"Juntao Wang, Li'an Shen, Xue Luo, Yuqing Zhang","doi":"10.1177/10567895251358292","DOIUrl":"https://doi.org/10.1177/10567895251358292","url":null,"abstract":"Research on bituminous material fatigue has traditionally focused on tensile or shear damage of bitumen and asphalt mixtures, neglecting the critical bitumen–aggregate interfaces where microcracks initiate. Addressing this gap, the pull-off fatigue crack (POF-C) model was built to predict crack propagation at these interfaces under pull-off cyclic loading. The model, based on continuum damage mechanics principles, integrates force equilibrium and dissipated strain energy equilibrium. Pull-off fatigue tests were conducted on interfaces using limestone, tuff, and basalt aggregates, with #70 matrix bitumen and styrene–butadiene–styrene copolymer-modified bitumen, at temperatures of 15°C and 20°C, and with bitumen film thicknesses ranging from 0.2 mm to 0.8 mm. Dynamic modulus and phase angle data informed the model inputs. Predicted crack sizes closely matched measured results on fractured surfaces, demonstrating less than 2% prediction error. Scanning electron microscope tests confirmed the model's validity, showing numerous circular mesh depressions on fracture surfaces. The POF-C model accurately forecasts POF-C lengths across varied conditions, revealing three distinct stages of crack propagation: a rapid growth (∼0.025 mm/cycle), a stable expansion stage (<0.025 mm/cycle), and a slow fatigue stage (∼0 mm/cycle). The fatigue mechanism involves the development of microdamage into microcracks, their nucleation and aggregation, and macrocrack throughout the entire bitumen–aggregate interface.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"15 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747362","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 : 2025-07-22DOI: 10.1177/10567895251360387
Raniere S Neves, Guilherme V Ferreira, Duarte JL Cachulo, Jose MA César de Sá, Abilio MP De Jesus, Lucival Malcher
This study proposes the extension of an incremental damage approach to fatigue life estimate presented by Neves and co-authors, assuming high-cycle fatigue regime, through the adoption of a two-scale damage approach previously proposed by Lemaitre. Under high-cycle fatigue conditions, plastic strain only occurs at the microstructural scale of a material. In this sense, it is not possible to use traditional damage models, whose damage evolution laws are governed by the plasticity and observed in the classical scale adopted by the continuum damage mechanics. An alternative approach was proposed by Lemaitre to separate the material behavior into two scales: one microscopic and the other macroscopic. In addition, a localization law is used to correlate the behavior of the material at both scales. Furthermore, the predictive capacity of the approach proposed in this paper is assessed by comparing the life values predicted by it and those observed experimentally from fatigue tests performed by force control on hourglass-shaped specimens made of grade R4 steel, a material used by the offshore industry in the manufacturing of mooring systems. In conclusion, the approach's predictive capability for fatigue life estimation showed 75% of results within a dispersion band of 2.
{"title":"A two-scale damage model for high-cycle fatigue life predictions following an incremental approach","authors":"Raniere S Neves, Guilherme V Ferreira, Duarte JL Cachulo, Jose MA César de Sá, Abilio MP De Jesus, Lucival Malcher","doi":"10.1177/10567895251360387","DOIUrl":"https://doi.org/10.1177/10567895251360387","url":null,"abstract":"This study proposes the extension of an incremental damage approach to fatigue life estimate presented by Neves and co-authors, assuming high-cycle fatigue regime, through the adoption of a two-scale damage approach previously proposed by Lemaitre. Under high-cycle fatigue conditions, plastic strain only occurs at the microstructural scale of a material. In this sense, it is not possible to use traditional damage models, whose damage evolution laws are governed by the plasticity and observed in the classical scale adopted by the continuum damage mechanics. An alternative approach was proposed by Lemaitre to separate the material behavior into two scales: one microscopic and the other macroscopic. In addition, a localization law is used to correlate the behavior of the material at both scales. Furthermore, the predictive capacity of the approach proposed in this paper is assessed by comparing the life values predicted by it and those observed experimentally from fatigue tests performed by force control on hourglass-shaped specimens made of grade R4 steel, a material used by the offshore industry in the manufacturing of mooring systems. In conclusion, the approach's predictive capability for fatigue life estimation showed 75% of results within a dispersion band of 2.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"13 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677419","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 practical engineering applications, rolling bearings and other critical components are typically subjected to complex, variable loading conditions. The coupled effects of load magnitude, frequency, and phase significantly accelerate the initiation and propagation of fatigue cracks. Although existing fatigue damage accumulation models partially account for load sequence and interaction, many of these models are overly complex and involve numerous parameters, making it challenging to strike a balance between accuracy and computational efficiency. To address this issue, this paper proposes a fatigue damage accumulation model based on nonlinear damage evolution theory, which simultaneously considers the effects of load interaction and material parameters under variable loading conditions. By incorporating the interaction factor and critical material parameters, the model more accurately characterizes the variations in load spectra and the differences in fatigue performance among different materials. Subsequently, the model was validated against cyclic loading test data for 16Mn steel, hot-rolled 16Mn steel, 30NiCrMoV12 steel, Ti–6Al–4V titanium alloy, GS-61 steel, Al2024–T42 aluminum alloy, C45 steel, Q235B steel, and Al6082–T6 aluminum alloy. Comparative analyses with the Miner rule, Manson–Halford model, Aeran's model, and its improved model demonstrated that the proposed model exhibits significant improvements in both predictive accuracy and generalization capability. Furthermore, to verify the model's applicability in real-world engineering environments, two rolling bearings subjected to variable operating conditions were selected for case studies. The results indicate that the model exhibits strong validity and applicability in fatigue life prediction, offering novel insights and methods for the safety assessment and life prediction of critical components subjected to complex loading spectra.
{"title":"A nonlinear fatigue damage accumulation model for rolling bearing life prediction considering coupled load-variation effects","authors":"Xinyu Ge, Chao Zhang, Wenyang Zhang, Ximing Zhang, Kexi Xu","doi":"10.1177/10567895251358415","DOIUrl":"https://doi.org/10.1177/10567895251358415","url":null,"abstract":"In practical engineering applications, rolling bearings and other critical components are typically subjected to complex, variable loading conditions. The coupled effects of load magnitude, frequency, and phase significantly accelerate the initiation and propagation of fatigue cracks. Although existing fatigue damage accumulation models partially account for load sequence and interaction, many of these models are overly complex and involve numerous parameters, making it challenging to strike a balance between accuracy and computational efficiency. To address this issue, this paper proposes a fatigue damage accumulation model based on nonlinear damage evolution theory, which simultaneously considers the effects of load interaction and material parameters under variable loading conditions. By incorporating the interaction factor and critical material parameters, the model more accurately characterizes the variations in load spectra and the differences in fatigue performance among different materials. Subsequently, the model was validated against cyclic loading test data for 16Mn steel, hot-rolled 16Mn steel, 30NiCrMoV12 steel, Ti–6Al–4V titanium alloy, GS-61 steel, Al2024–T42 aluminum alloy, C45 steel, Q235B steel, and Al6082–T6 aluminum alloy. Comparative analyses with the Miner rule, Manson–Halford model, Aeran's model, and its improved model demonstrated that the proposed model exhibits significant improvements in both predictive accuracy and generalization capability. Furthermore, to verify the model's applicability in real-world engineering environments, two rolling bearings subjected to variable operating conditions were selected for case studies. The results indicate that the model exhibits strong validity and applicability in fatigue life prediction, offering novel insights and methods for the safety assessment and life prediction of critical components subjected to complex loading spectra.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"704 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685156","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}
The notched titanium alloys after laser cladding are often accompanied by anisotropic microstructural effects and metastable microstructures, and estimation of its remaining lifespan and fracture behavior becomes challenging. In this study, the effective fracture surface area of laser-cladded notched titanium alloy under different stress ratios is defined as an indicator of proposed dissipative energy damage model. The infrared thermographic cyclic tests are firstly conducted on repaired specimens of notched titanium alloy. Both fine granular area morphology and irregular nanoparticles are observed in crack initiation and early propagation zones from fatigue fracture surfaces. To better explain this phenomenon, the micro-strain field of the specimens under cyclic loading is measured using digital image correlation method. Then, the relationship between the effective fracture surface area and the stress amplitude is established, as well as an equivalent crack propagation rate. The predicted remaining lifespan of laser-cladded notched titanium alloy based on the dissipative energy damage model agrees well with the experimental data.
{"title":"Fatigue fracture analysis and lifetime prediction of laser-cladded notched titanium alloy based on energy dissipation method","authors":"Chengji Mi, Yongqiang Li, Yingang Xiao, Haiqi Li, Liang Xu, Jiachang Tang","doi":"10.1177/10567895251358290","DOIUrl":"https://doi.org/10.1177/10567895251358290","url":null,"abstract":"The notched titanium alloys after laser cladding are often accompanied by anisotropic microstructural effects and metastable microstructures, and estimation of its remaining lifespan and fracture behavior becomes challenging. In this study, the effective fracture surface area of laser-cladded notched titanium alloy under different stress ratios is defined as an indicator of proposed dissipative energy damage model. The infrared thermographic cyclic tests are firstly conducted on repaired specimens of notched titanium alloy. Both fine granular area morphology and irregular nanoparticles are observed in crack initiation and early propagation zones from fatigue fracture surfaces. To better explain this phenomenon, the micro-strain field of the specimens under cyclic loading is measured using digital image correlation method. Then, the relationship between the effective fracture surface area and the stress amplitude is established, as well as an equivalent crack propagation rate. The predicted remaining lifespan of laser-cladded notched titanium alloy based on the dissipative energy damage model agrees well with the experimental data.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"669 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144639820","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}
The viscoelastic damage evolution at the microscale particle interfaces of asphalt mortar or mixtures fundamentally determines the material's fatigue crack growth and failure at the macroscale. However, existing microscale damage models are often based on empirical assumptions that depend on interparticle stresses or forces, which are inaccurate or even incorrect for viscoelastic asphalt materials. In these materials, interfacial crack growth is governed by the viscoelastic energy release rate. To address the limitations of current models, a microscale viscoelastic fatigue damage model was developed using a pseudo J-integral-based Paris’ law and implemented in a discrete element model of asphalt mortar using the PFC2D program. The viscoelastic constitutive behavior was represented by a generalized Maxwell model, and the relaxation moduli were determined through a uniaxial compressive dynamic modulus test. The Paris’ law coefficients were calibrated by comparing model predictions with experimental results from indirect tensile fatigue tests of the material. The results show that the simulated fatigue life and crack area closely match laboratory test data, with an error margin within 15%. During the simulation of microscopic IDT fatigue damage, cracks hinder the horizontal transfer of forces within the cracked region, leading to stress concentrations in surrounding particles and a marked increase in their relative displacement. The connection of upper and lower cracks significantly reduces the specimen's load-bearing capacity. The variation in the number of contact breaks with fatigue load cycles is unaffected by the type of asphalt but is influenced by the applied stress level. These findings demonstrate that the pseudo J-integral-based Paris’ law, when applied at particle interfaces, can effectively model crack growth at the microscale and accurately predict the fatigue damage performance of viscoelastic asphalt materials at the macroscale.
{"title":"Microscale modeling of fatigue crack growth at particle interfaces in viscoelastic asphalt materials","authors":"Li’an Shen, Juntao Wang, Chonghui Wang, Xue Luo, Yuqing Zhang","doi":"10.1177/10567895251358293","DOIUrl":"https://doi.org/10.1177/10567895251358293","url":null,"abstract":"The viscoelastic damage evolution at the microscale particle interfaces of asphalt mortar or mixtures fundamentally determines the material's fatigue crack growth and failure at the macroscale. However, existing microscale damage models are often based on empirical assumptions that depend on interparticle stresses or forces, which are inaccurate or even incorrect for viscoelastic asphalt materials. In these materials, interfacial crack growth is governed by the viscoelastic energy release rate. To address the limitations of current models, a microscale viscoelastic fatigue damage model was developed using a pseudo J-integral-based Paris’ law and implemented in a discrete element model of asphalt mortar using the PFC2D program. The viscoelastic constitutive behavior was represented by a generalized Maxwell model, and the relaxation moduli were determined through a uniaxial compressive dynamic modulus test. The Paris’ law coefficients were calibrated by comparing model predictions with experimental results from indirect tensile fatigue tests of the material. The results show that the simulated fatigue life and crack area closely match laboratory test data, with an error margin within 15%. During the simulation of microscopic IDT fatigue damage, cracks hinder the horizontal transfer of forces within the cracked region, leading to stress concentrations in surrounding particles and a marked increase in their relative displacement. The connection of upper and lower cracks significantly reduces the specimen's load-bearing capacity. The variation in the number of contact breaks with fatigue load cycles is unaffected by the type of asphalt but is influenced by the applied stress level. These findings demonstrate that the pseudo J-integral-based Paris’ law, when applied at particle interfaces, can effectively model crack growth at the microscale and accurately predict the fatigue damage performance of viscoelastic asphalt materials at the macroscale.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"280 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144629839","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 : 2025-07-14DOI: 10.1177/10567895251357958
Jun Xu, Lu Ma, Xiaochun Xiao
To clarify the damage evolution of rock-like materials with defects under cyclic loading, gypsum specimens containing prefabricated nonpenetrating crack(s) are employed to undertake a quantitative study of the energy in the failure process of brittle materials under cyclic loading. The results show that under cyclic loading, the laws of energy accumulation, transformation, and release can effectively reflect the damage evolution process of rock-like materials. In the damage process of gypsum specimen, the number of nonpenetrating cracks can influence the elastic energy density, the total energy density, and dissipated energy density. The surface free energy of new cracks tends to increase to a certain extent as the number of cycles increases. Additionally, the expressions for the total energy, stored energy, dissipated energy, and damage of the gypsum specimen under cyclic loading are derived and tested through the experimental results. A quantitative analysis and calculation of the crack surface energy have also been conducted, along with an estimation and analysis of the microcrack surface free energy. These findings are of great significance for understanding the mechanisms of rock failure and rock engineering disasters in deep rock engineering, such as spalling, collapse, and rock burst, from the perspective of energy accumulation, transformation, and release.
{"title":"Energy characteristics of rocks prior to macroscopic fracture under cyclic loading","authors":"Jun Xu, Lu Ma, Xiaochun Xiao","doi":"10.1177/10567895251357958","DOIUrl":"https://doi.org/10.1177/10567895251357958","url":null,"abstract":"To clarify the damage evolution of rock-like materials with defects under cyclic loading, gypsum specimens containing prefabricated nonpenetrating crack(s) are employed to undertake a quantitative study of the energy in the failure process of brittle materials under cyclic loading. The results show that under cyclic loading, the laws of energy accumulation, transformation, and release can effectively reflect the damage evolution process of rock-like materials. In the damage process of gypsum specimen, the number of nonpenetrating cracks can influence the elastic energy density, the total energy density, and dissipated energy density. The surface free energy of new cracks tends to increase to a certain extent as the number of cycles increases. Additionally, the expressions for the total energy, stored energy, dissipated energy, and damage of the gypsum specimen under cyclic loading are derived and tested through the experimental results. A quantitative analysis and calculation of the crack surface energy have also been conducted, along with an estimation and analysis of the microcrack surface free energy. These findings are of great significance for understanding the mechanisms of rock failure and rock engineering disasters in deep rock engineering, such as spalling, collapse, and rock burst, from the perspective of energy accumulation, transformation, and release.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"13 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144622487","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 : 2025-06-23DOI: 10.1177/10567895251338005
Yao Zhang, Pan Feng, Weigang Zhao, Guowen Sun, Zhiguo Yan, Hehua Zhu, J. Woody Ju
Multiscale fiber-reinforced ultra-high performance concrete (MSFUHPC) was recently developed to obtain the desired thermal and mechanical properties for engineering structures suffering from fire accidents. Quantitative methods to characterize the evolution of its thermal damage are necessary to design MSFUHPC and remain to be presented. This study presents an improved micromechanical model focusing on the material's stiffness from hydration through dehydration to thermal damage. MSFUHPC is renowned for its exceptional mechanical properties and durability; however, its susceptibility to thermal degradation poses significant challenges, particularly in fire scenarios. The integration of multiscale fibers—comprising steel, polyethylene, and carbon fibers and carbon nanotubes—alongside lightweight aggregates such as fly ash cenospheres, enhances the material's performance subjected to elevated temperatures. The proposed micromechanical model captures the complex interactions between the fibers, sand and cement matrix at various scales. By considering the effects of hydration and dehydration, the model offers valuable insights into the mechanisms leading to thermal damage during thermal exposure. Moreover, two Weibull probabilistic models are introduced to characterize the evolution of thermal cracking and sand debonding. Experimental studies are carried out to estimate the thermal and mechanical properties of MSFUHPC, thereby validating the model's feasibility. The results indicate that the multiscale fiber reinforcement significantly mitigates thermal damage. These findings underscore the importance of optimizing fiber and aggregate combinations to achieve superior fire resistance. Moreover, the proposed micromechanical model can serve as input parameters for thermomechanically coupled analysis of structures and components.
{"title":"An improved micromechanical model for multiscale fiber reinforced ultra-high performance concrete: From hydration, dehydration to thermal damage","authors":"Yao Zhang, Pan Feng, Weigang Zhao, Guowen Sun, Zhiguo Yan, Hehua Zhu, J. Woody Ju","doi":"10.1177/10567895251338005","DOIUrl":"https://doi.org/10.1177/10567895251338005","url":null,"abstract":"Multiscale fiber-reinforced ultra-high performance concrete (MSFUHPC) was recently developed to obtain the desired thermal and mechanical properties for engineering structures suffering from fire accidents. Quantitative methods to characterize the evolution of its thermal damage are necessary to design MSFUHPC and remain to be presented. This study presents an improved micromechanical model focusing on the material's stiffness from hydration through dehydration to thermal damage. MSFUHPC is renowned for its exceptional mechanical properties and durability; however, its susceptibility to thermal degradation poses significant challenges, particularly in fire scenarios. The integration of multiscale fibers—comprising steel, polyethylene, and carbon fibers and carbon nanotubes—alongside lightweight aggregates such as fly ash cenospheres, enhances the material's performance subjected to elevated temperatures. The proposed micromechanical model captures the complex interactions between the fibers, sand and cement matrix at various scales. By considering the effects of hydration and dehydration, the model offers valuable insights into the mechanisms leading to thermal damage during thermal exposure. Moreover, two Weibull probabilistic models are introduced to characterize the evolution of thermal cracking and sand debonding. Experimental studies are carried out to estimate the thermal and mechanical properties of MSFUHPC, thereby validating the model's feasibility. The results indicate that the multiscale fiber reinforcement significantly mitigates thermal damage. These findings underscore the importance of optimizing fiber and aggregate combinations to achieve superior fire resistance. Moreover, the proposed micromechanical model can serve as input parameters for thermomechanically coupled analysis of structures and components.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"49 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341111","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 : 2025-06-18DOI: 10.1177/10567895251329702
Peifeng Li, Guoshao Su, Salvatore Martino, Zonghui Liu, Shihong Hu
In deep rock engineering, rocks adjacent to excavation boundaries, subjected to biaxial compression, frequently encounter severe static and dynamic hazards induced by construction activities. These processes generate abundant sound signals associated with rock pre-failures, although the beneficial characteristics of these signals remain inadequately understood. Their potential drives us to comprehensively explore the precursory and damage characteristics of static (spalling) and dynamic (rockburst) failures in granite under biaxial compression with different loading rates using sound signals. Based on the characteristic analysis of sound signals in the time and frequency domains, we identified multiple precursors correlated with the rock failures and introduced a prediction method for determining the rock failure modes (spalling and rockburst). Subsequently, the strong effects of loading rate on the sound precursors were revealed. Moreover, the proposed sound-based damage constitutive model for granite under biaxial compression with different loading rates was proven to be feasible. Furthermore, the amplitude-frequency properties of sound signals produced by rock cracking under biaxial compression were uncovered. The research results of this study improve the prediction and warning of static-dynamic mechanisms driven rock failures under biaxial compression through sound monitoring technology.
{"title":"Precursory and damage characteristics of static and dynamic failures in granite under biaxial compression with different loading rates: Insight from sound signals","authors":"Peifeng Li, Guoshao Su, Salvatore Martino, Zonghui Liu, Shihong Hu","doi":"10.1177/10567895251329702","DOIUrl":"https://doi.org/10.1177/10567895251329702","url":null,"abstract":"In deep rock engineering, rocks adjacent to excavation boundaries, subjected to biaxial compression, frequently encounter severe static and dynamic hazards induced by construction activities. These processes generate abundant sound signals associated with rock pre-failures, although the beneficial characteristics of these signals remain inadequately understood. Their potential drives us to comprehensively explore the precursory and damage characteristics of static (spalling) and dynamic (rockburst) failures in granite under biaxial compression with different loading rates using sound signals. Based on the characteristic analysis of sound signals in the time and frequency domains, we identified multiple precursors correlated with the rock failures and introduced a prediction method for determining the rock failure modes (spalling and rockburst). Subsequently, the strong effects of loading rate on the sound precursors were revealed. Moreover, the proposed sound-based damage constitutive model for granite under biaxial compression with different loading rates was proven to be feasible. Furthermore, the amplitude-frequency properties of sound signals produced by rock cracking under biaxial compression were uncovered. The research results of this study improve the prediction and warning of static-dynamic mechanisms driven rock failures under biaxial compression through sound monitoring technology.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"51 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319885","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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