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}
Pub Date : 2025-06-16DOI: 10.1177/10567895251346021
Bin Li, Zhiwu Zhu, Wurong Jia, Zhengqiang Cheng, Tao Li
Frozen-soils with different moisture contents (MCs) often experience freeze-thaw cycles (FTCs) owing to fluctuations in seasonal or day-night temperature. The influence of FTC on the impact dynamic mechanical properties of frozen-soils with different MCs was investigated in this study. The impact dynamic compression tests on frozen-soils with different MCs (20%, 25%, and 30%) following varying numbers of FTC (0, 1, 3, 5, and 7) using a split Hopkinson pressure bar apparatus were conducted. The experimental results revealed that the impact dynamic strength of the frozen-soil was related to the number of FTC and MC. A threshold exists for the number of FTC for the frozen-soil. Before reaching this threshold, the impact dynamic strength of the frozen-soil progressively decreased with an increasing number of FTC. Further, the threshold decreased as the MC decreased. Analyzing the energy of frozen-soil during impact process, an expression for the FTC damage in frozen-soils with different MCs was established using the energy density. The reinforcing effect of ice particles on the impact dynamic mechanical properties of frozen-soil was examined, and the elastic constants for the frozen-soils with different MCs were evaluated using micromechanical theory. Furthermore, a finite element numerical model of frozen-soil was developed by integrating cohesive elements into solid elements via Python scripting using the cohesive zone model. The impact dynamic mechanical behavior and crack evolution behavior of frozen-soils with different MCs following varying numbers of FTCs were simulated by considering the mechanisms of FTC degradation and ice particles reinforcement. The validity of the model was confirmed by comparing simulation and experimental results.
{"title":"Impact dynamic mechanical properties of frozen-soils with different moisture contents following varying numbers of freeze-thaw cycle","authors":"Bin Li, Zhiwu Zhu, Wurong Jia, Zhengqiang Cheng, Tao Li","doi":"10.1177/10567895251346021","DOIUrl":"https://doi.org/10.1177/10567895251346021","url":null,"abstract":"Frozen-soils with different moisture contents (MCs) often experience freeze-thaw cycles (FTCs) owing to fluctuations in seasonal or day-night temperature. The influence of FTC on the impact dynamic mechanical properties of frozen-soils with different MCs was investigated in this study. The impact dynamic compression tests on frozen-soils with different MCs (20%, 25%, and 30%) following varying numbers of FTC (0, 1, 3, 5, and 7) using a split Hopkinson pressure bar apparatus were conducted. The experimental results revealed that the impact dynamic strength of the frozen-soil was related to the number of FTC and MC. A threshold exists for the number of FTC for the frozen-soil. Before reaching this threshold, the impact dynamic strength of the frozen-soil progressively decreased with an increasing number of FTC. Further, the threshold decreased as the MC decreased. Analyzing the energy of frozen-soil during impact process, an expression for the FTC damage in frozen-soils with different MCs was established using the energy density. The reinforcing effect of ice particles on the impact dynamic mechanical properties of frozen-soil was examined, and the elastic constants for the frozen-soils with different MCs were evaluated using micromechanical theory. Furthermore, a finite element numerical model of frozen-soil was developed by integrating cohesive elements into solid elements via Python scripting using the cohesive zone model. The impact dynamic mechanical behavior and crack evolution behavior of frozen-soils with different MCs following varying numbers of FTCs were simulated by considering the mechanisms of FTC degradation and ice particles reinforcement. The validity of the model was confirmed by comparing simulation and experimental results.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"25 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144304841","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 : 2025-06-09DOI: 10.1177/10567895251329946
Jiahui Shen, Mário Rui Tiago Arruda, Alfonso Pagani
This paper provides an extensive review of popular regularization methods utilized in numerical models to stabilize the structural response of materials exhibiting significant softening. The necessity for regularization is highlighted in cases of material softening, which is attributed to the loss of ellipticity in the governing differential equations. It discusses the advantages and disadvantages of the regularization methods most commonly employed in the scientific community. Furthermore, the paper highlights recent advancements, particularly in defining internal length within nonlocal models and characteristic element length in fracture energy regularization methods, as alternative solutions to address the limitations inherent in traditional approaches.
{"title":"State of art in regularization methods for numerical analysis of structures with softening","authors":"Jiahui Shen, Mário Rui Tiago Arruda, Alfonso Pagani","doi":"10.1177/10567895251329946","DOIUrl":"https://doi.org/10.1177/10567895251329946","url":null,"abstract":"This paper provides an extensive review of popular regularization methods utilized in numerical models to stabilize the structural response of materials exhibiting significant softening. The necessity for regularization is highlighted in cases of material softening, which is attributed to the loss of ellipticity in the governing differential equations. It discusses the advantages and disadvantages of the regularization methods most commonly employed in the scientific community. Furthermore, the paper highlights recent advancements, particularly in defining internal length within nonlocal models and characteristic element length in fracture energy regularization methods, as alternative solutions to address the limitations inherent in traditional approaches.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"139 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144252140","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 : 2025-05-29DOI: 10.1177/10567895251346275
George Z. Voyiadjis
{"title":"Preface to the special issues of the International Journal of Damage Mechanics","authors":"George Z. Voyiadjis","doi":"10.1177/10567895251346275","DOIUrl":"https://doi.org/10.1177/10567895251346275","url":null,"abstract":"","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"147 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165422","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 : 2025-05-21DOI: 10.1177/10567895251342399
Mohamed Chairi, Jalal El Bahaoui, Issam Hanafi, Federica Favaloro, Chiara Borsellino, Fabia Galantini, Guido Di Bella
In response to environmental challenges and the demand for sustainability, this study explores a novel engineering structure, harnessing the potential of bio-based materials within the framework of composite sandwich structures. This investigation employs finite element modeling to assess sandwich structures composed of End-grain balsa wood and fiber-reinforced polymer (FRP) facesheets. These facesheets incorporate glass, carbon, and basalt fibers, enabling a direct comparison between conventional and bio-based materials. Mechanical responses are evaluated under numerical flexural loading using Abaqus/Implicit, with a specialized wood material model integrated via a User Material (UMAT) subroutine. A 2D Hashin failure criterion assesses FRP facesheets. Intriguingly, findings indicate minimal influence from FRP on structural performance, while balsa wood and the core-casings interface emerge as decisive factors.
{"title":"Computational assessment of sustainable balsa and basalt composite sandwich for structural marine applications","authors":"Mohamed Chairi, Jalal El Bahaoui, Issam Hanafi, Federica Favaloro, Chiara Borsellino, Fabia Galantini, Guido Di Bella","doi":"10.1177/10567895251342399","DOIUrl":"https://doi.org/10.1177/10567895251342399","url":null,"abstract":"In response to environmental challenges and the demand for sustainability, this study explores a novel engineering structure, harnessing the potential of bio-based materials within the framework of composite sandwich structures. This investigation employs finite element modeling to assess sandwich structures composed of End-grain balsa wood and fiber-reinforced polymer (FRP) facesheets. These facesheets incorporate glass, carbon, and basalt fibers, enabling a direct comparison between conventional and bio-based materials. Mechanical responses are evaluated under numerical flexural loading using Abaqus/Implicit, with a specialized wood material model integrated via a User Material (UMAT) subroutine. A 2D Hashin failure criterion assesses FRP facesheets. Intriguingly, findings indicate minimal influence from FRP on structural performance, while balsa wood and the core-casings interface emerge as decisive factors.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"122 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113860","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 : 2025-05-14DOI: 10.1177/10567895251329815
Tim van der Velden, Stefanie Reese, Hagen Holthusen, Tim Brepols
This paper establishes a generic framework for the nonlocal modeling of anisotropic damage at finite strains. By the combination of two recent works, the new framework allows for the flexible incorporation of different established hyperelastic finite strain material formulations into anisotropic damage whilst ensuring mesh-independent results by employing a generic set of micromorphic gradient-extensions. First, the anisotropic damage model, generally satisfying the damage growth criterion, is investigated for the specific choice of a neo-Hookean material on a single element. Next, the model is applied with different gradient-extensions in structural simulations of an asymmetrically notched specimen to identify an efficient choice in the form of a volumetric–deviatoric regularization. Thereafter, the generic framework, which is without loss of generality here specified for a neo-Hookean material with a volumetric–deviatoric gradient-extension, successfully serves for the complex simulation of a pressure-loaded rotor blade. The codes of the material subroutines are accessible to the public at https://doi.org/10.5281/zenodo.11171630 .
{"title":"An anisotropic, brittle damage model for finite strains with a generic damage tensor regularization","authors":"Tim van der Velden, Stefanie Reese, Hagen Holthusen, Tim Brepols","doi":"10.1177/10567895251329815","DOIUrl":"https://doi.org/10.1177/10567895251329815","url":null,"abstract":"This paper establishes a generic framework for the nonlocal modeling of anisotropic damage at finite strains. By the combination of two recent works, the new framework allows for the flexible incorporation of different established hyperelastic finite strain material formulations into anisotropic damage whilst ensuring mesh-independent results by employing a generic set of micromorphic gradient-extensions. First, the anisotropic damage model, generally satisfying the damage growth criterion, is investigated for the specific choice of a neo-Hookean material on a single element. Next, the model is applied with different gradient-extensions in structural simulations of an asymmetrically notched specimen to identify an efficient choice in the form of a volumetric–deviatoric regularization. Thereafter, the generic framework, which is without loss of generality here specified for a neo-Hookean material with a volumetric–deviatoric gradient-extension, successfully serves for the complex simulation of a pressure-loaded rotor blade. The codes of the material subroutines are accessible to the public at <jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" ext-link-type=\"uri\" xlink:href=\"https://doi.org/10.5281/zenodo.11171630\">https://doi.org/10.5281/zenodo.11171630</jats:ext-link> .","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"13 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143980028","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 : 2025-04-17DOI: 10.1177/10567895251329950
Yanmo Weng, Pizhong Qiao, Lizhi Sun
This study aims to investigate the tensile behavior of ultra-high performance concrete (UHPC) using a multiscale modeling approach. A micromechanics-based finite-element method is employed to investigate the evolution of microstructural damage and its effect on the macroscopic tensile strength of UHPC. X-ray computed tomography (CT) techniques are used to create a realistic microstructural geometry, and the cohesive-zone models are adopted to quantify the microcrack growth rate and the overall mechanical properties of UHPC under tension. A stiffness-degradation parameter is introduced to explain the evolution of the material tensile behavior. Satisfactory agreements are achieved between the simulation results and the experimental data from the direct tensile tests. To demonstrate the capability of the proposed multiscale modeling framework, the influences of curing age and freeze–thaw cycles of UHPC materials are further taken into account. The proposed multiscale simulation scheme integrated with the x-ray CT techniques and cohesive-zone model can serve as an effective and reliable method to capture the nonlinear tensile responses of UHPC materials and structures.
本研究旨在采用多尺度建模方法研究超高性能混凝土(UHPC)的拉伸行为。研究采用了基于微观力学的有限元方法来研究微观结构损伤的演变及其对超高强混凝土宏观抗拉强度的影响。利用 X 射线计算机断层扫描(CT)技术创建了逼真的微观结构几何形状,并采用内聚区模型来量化微裂纹的增长速度和拉伸条件下超高强度混凝土的整体力学性能。引入了刚度降解参数来解释材料拉伸行为的演变。模拟结果与直接拉伸试验的实验数据之间达到了令人满意的一致。为了证明所提出的多尺度建模框架的能力,还进一步考虑了 UHPC 材料的固化龄期和冻融循环的影响。所提出的多尺度模拟方案与 X 射线 CT 技术和内聚区模型相结合,可作为捕捉 UHPC 材料和结构非线性拉伸响应的有效而可靠的方法。
{"title":"Effect of microstructural damage evolution on tensile strength of ultra-high performance concrete: A multiscale numerical scheme","authors":"Yanmo Weng, Pizhong Qiao, Lizhi Sun","doi":"10.1177/10567895251329950","DOIUrl":"https://doi.org/10.1177/10567895251329950","url":null,"abstract":"This study aims to investigate the tensile behavior of ultra-high performance concrete (UHPC) using a multiscale modeling approach. A micromechanics-based finite-element method is employed to investigate the evolution of microstructural damage and its effect on the macroscopic tensile strength of UHPC. X-ray computed tomography (CT) techniques are used to create a realistic microstructural geometry, and the cohesive-zone models are adopted to quantify the microcrack growth rate and the overall mechanical properties of UHPC under tension. A stiffness-degradation parameter is introduced to explain the evolution of the material tensile behavior. Satisfactory agreements are achieved between the simulation results and the experimental data from the direct tensile tests. To demonstrate the capability of the proposed multiscale modeling framework, the influences of curing age and freeze–thaw cycles of UHPC materials are further taken into account. The proposed multiscale simulation scheme integrated with the x-ray CT techniques and cohesive-zone model can serve as an effective and reliable method to capture the nonlinear tensile responses of UHPC materials and structures.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"122 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841838","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 : 2025-04-17DOI: 10.1177/10567895251329943
David Leonardo Nascimento de Figueiredo Amorim, Sergio Persival Baroncini Proença, Julio Flórez-López
This paper proposes a procedure for analyzing crack propagation in complex structures based on lumped damage mechanics. This theory combines the concept of a plastic hinge with the procedures of damage and fracture mechanics. Models of damage for monotonic loading and high-cycle fatigue are proposed. The paper also describes the numerical implementation of the models in conventional finite-element programs. The models are validated by comparison with experimental results and classic fracture mechanics analyses. It is shown that the model can be used in multi-scale schemes for the structural assessment of structures in civil, offshore, and aeronautical engineering. Therefore, the proposed model might be useful as a macro-modeling step in multi-scale analysis, as well as a tool for preliminary analysis of structures under fatigue loads.
{"title":"Formulation for the matrix analysis of frame structures including fracture mechanics concepts: Applications in tunnel linings and airplane fuselage panels","authors":"David Leonardo Nascimento de Figueiredo Amorim, Sergio Persival Baroncini Proença, Julio Flórez-López","doi":"10.1177/10567895251329943","DOIUrl":"https://doi.org/10.1177/10567895251329943","url":null,"abstract":"This paper proposes a procedure for analyzing crack propagation in complex structures based on lumped damage mechanics. This theory combines the concept of a plastic hinge with the procedures of damage and fracture mechanics. Models of damage for monotonic loading and high-cycle fatigue are proposed. The paper also describes the numerical implementation of the models in conventional finite-element programs. The models are validated by comparison with experimental results and classic fracture mechanics analyses. It is shown that the model can be used in multi-scale schemes for the structural assessment of structures in civil, offshore, and aeronautical engineering. Therefore, the proposed model might be useful as a macro-modeling step in multi-scale analysis, as well as a tool for preliminary analysis of structures under fatigue loads.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"122 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841837","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 : 2025-04-17DOI: 10.1177/10567895251331310
Haotian Sun, Diqing Fan, Xintian Liu, Jiazhi Liu, Haiyan Ge
Accurate prediction of the fatigue life of API X65 steel is crucial in various applications. However, the traditional bootstrap method has inherent limitations, such as a tendency to deviate from the true distribution with insufficient sample sizes, difficulty in identifying extreme statistics, and an inability to generate distributions closer to the original sample. These deficiencies lead to overly conservative S-N curve designs and pose challenges in data collection, particularly for small samples. To address these issues, we propose an improved bootstrap method using a composite probability distribution. This method enhances the sampling range and improves prediction accuracy for parameter uncertainty ranges by considering both small samples and extended virtual samples’ probability distribution. Comparative analysis through Monte Carlo simulation demonstrates the superior parameter estimation of our method for small samples. Our case analysis further explores the relationships between Vickers hardness, tensile strength, surface roughness factor, and intercept constant. The findings led to a novel method for estimating the S-N curve confidence interval of API X65 steel from Vickers hardness. Analysis of fatigue life test data for API X65 steel yielded favorable results, confirming the effectiveness and feasibility of our improved method.
{"title":"Composite probability distribution for fatigue life prediction of API X65 steel via Vickers hardness","authors":"Haotian Sun, Diqing Fan, Xintian Liu, Jiazhi Liu, Haiyan Ge","doi":"10.1177/10567895251331310","DOIUrl":"https://doi.org/10.1177/10567895251331310","url":null,"abstract":"Accurate prediction of the fatigue life of API X65 steel is crucial in various applications. However, the traditional bootstrap method has inherent limitations, such as a tendency to deviate from the true distribution with insufficient sample sizes, difficulty in identifying extreme statistics, and an inability to generate distributions closer to the original sample. These deficiencies lead to overly conservative S-N curve designs and pose challenges in data collection, particularly for small samples. To address these issues, we propose an improved bootstrap method using a composite probability distribution. This method enhances the sampling range and improves prediction accuracy for parameter uncertainty ranges by considering both small samples and extended virtual samples’ probability distribution. Comparative analysis through Monte Carlo simulation demonstrates the superior parameter estimation of our method for small samples. Our case analysis further explores the relationships between Vickers hardness, tensile strength, surface roughness factor, and intercept constant. The findings led to a novel method for estimating the S-N curve confidence interval of API X65 steel from Vickers hardness. Analysis of fatigue life test data for API X65 steel yielded favorable results, confirming the effectiveness and feasibility of our improved method.","PeriodicalId":13837,"journal":{"name":"International Journal of Damage Mechanics","volume":"17 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143841835","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}