Pub Date : 2026-05-02Epub Date: 2026-02-24DOI: 10.1016/j.engfracmech.2026.111988
Qihui Lyu , Lanlan Jiang , Ben Wang , Pingping Yang , Biao Wang
This study investigates the impact resistance and damage tolerance of bio-inspired cross-spiral composite materials under multiple low-velocity impacts, with a focus on the effects of different impact parameters (including the number of impacts, single-impact energy, and impact sequence) under the condition of constant total impact energy on the damage behavior and failure mechanisms of the laminates. Using a combined experimental and numerical simulation approach, the study systematically analyzes the influence of these impact parameters on the mechanical response, delamination area, intralaminar damage extent, damage evolution behavior, and compression-after-impact (CAI) strength of the laminates. The results indicate that, under a fixed total energy condition, the maximum single-impact energy in multiple impacts is the key factor affecting the impact resistance of the laminates. However, variations in the number of impacts and single-impact energy have a relatively limited effect on the damage tolerance of the laminates. Additionally, the impact sequence shows no significant influence on either the impact resistance or the CAI strength. The findings of this study provide valuable insights for the application of bio-inspired composite materials in aerospace and ground transportation equipment.
{"title":"Progressive damage and failure mechanisms of bio-inspired cross-spiral composite laminates subjected to sequential low-velocity impacts and post-impact compression","authors":"Qihui Lyu , Lanlan Jiang , Ben Wang , Pingping Yang , Biao Wang","doi":"10.1016/j.engfracmech.2026.111988","DOIUrl":"10.1016/j.engfracmech.2026.111988","url":null,"abstract":"<div><div>This study investigates the impact resistance and damage tolerance of bio-inspired cross-spiral composite materials under multiple low-velocity impacts, with a focus on the effects of different impact parameters (including the number of impacts, single-impact energy, and impact sequence) under the condition of constant total impact energy on the damage behavior and failure mechanisms of the laminates. Using a combined experimental and numerical simulation approach, the study systematically analyzes the influence of these impact parameters on the mechanical response, delamination area, intralaminar damage extent, damage evolution behavior, and compression-after-impact (CAI) strength of the laminates. The results indicate that, under a fixed total energy condition, the maximum single-impact energy in multiple impacts is the key factor affecting the impact resistance of the laminates. However, variations in the number of impacts and single-impact energy have a relatively limited effect on the damage tolerance of the laminates. Additionally, the impact sequence shows no significant influence on either the impact resistance or the CAI strength. The findings of this study provide valuable insights for the application of bio-inspired composite materials in aerospace and ground transportation equipment.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 111988"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387382","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 : 2026-05-02Epub Date: 2026-03-01DOI: 10.1016/j.engfracmech.2026.112004
Zhiwei Zhao, Chengbin Du, Yunlong Liu
This paper extends the recently proposed nonlocal macro–meso-scale damage (NMMD) model to the 3D, incorporating spatial interaction and energy degradation to simulate crack propagation. By unifying key features of peridynamics and phase-field approaches, the model automatically evolves crack paths without the cumbersome explicit tracking of complex 3D fracture surfaces. Unlike earlier 2D NMMD formulations, each macroscopic material point is now equipped with a spherical influence domain that characterizes the underlying mesostructure. To achieve accurate crack simulation, an octree polyhedral mesh and boundary trimming technology are used to ensure smooth mesh size transition and boundary adaptability. This study capitalizes on the inherent advantage of the polyhedral scaled boundary finite element method (SBFEM), which can effectively handle arbitrary polyhedral elements without restrictions on the shape of the boundary faces and seamlessly combine with the octree polyhedral mesh. A 3D patch test confirms that Wachspress or Laplace shape functions coupled with the octree polyhedral mesh deliver markedly higher accuracy than the mean value shape function alternative in polyhedral SBFEM analyses does. The reliability of the coupled NMMD–polyhedral SBFEM framework is validated through three classical examples and a typical engineering failure problem. The numerical results indicate that the proposed model accurately captures the entire cracking process and provides quantitative predictions of the load–deformation response. The combination of the NMMD model and polyhedral SBFEM enables efficient and robust nonlinear solutions, providing a new approach for the 3D fracture simulation of quasi-brittle materials such as concrete.
{"title":"Three-dimensional nonlocal damage modelling of fractures in quasi-brittle materials using the octree polyhedral scaled boundary finite element method","authors":"Zhiwei Zhao, Chengbin Du, Yunlong Liu","doi":"10.1016/j.engfracmech.2026.112004","DOIUrl":"10.1016/j.engfracmech.2026.112004","url":null,"abstract":"<div><div>This paper extends the recently proposed nonlocal macro–<em>meso</em>-scale damage (NMMD) model to the 3D, incorporating spatial interaction and energy degradation to simulate crack propagation. By unifying key features of peridynamics and phase-field approaches, the model automatically evolves crack paths without the cumbersome explicit tracking of complex 3D fracture surfaces. Unlike earlier 2D NMMD formulations, each macroscopic material point is now equipped with a spherical influence domain that characterizes the underlying mesostructure. To achieve accurate crack simulation, an octree polyhedral mesh and boundary trimming technology are used to ensure smooth mesh size transition and boundary adaptability. This study capitalizes on the inherent advantage of the polyhedral scaled boundary finite element method (SBFEM), which can effectively handle arbitrary polyhedral elements without restrictions on the shape of the boundary faces and seamlessly combine with the octree polyhedral mesh. A 3D patch test confirms that Wachspress or Laplace shape functions coupled with the octree polyhedral mesh deliver markedly higher accuracy than the mean value shape function alternative in polyhedral SBFEM analyses does. The reliability of the coupled NMMD–polyhedral SBFEM framework is validated through three classical examples and a typical engineering failure problem. The numerical results indicate that the proposed model accurately captures the entire cracking process and provides quantitative predictions of the load–deformation response. The combination of the NMMD model and polyhedral SBFEM enables efficient and robust nonlinear solutions, providing a new approach for the 3D fracture simulation of quasi-brittle materials such as concrete.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 112004"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387338","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 : 2026-05-02Epub Date: 2026-03-02DOI: 10.1016/j.engfracmech.2026.112008
Jinglue Hu , Jidong Kang , Wenxing Zhou
Running ductile fracture is a severe failure mode of dense-phase carbon dioxide (CO2) pipelines due to the sustained high crack-driving force associated with CO2 decompression. Crack arrestors have emerged as a viable option for fracture control; externally mounted steel and fiber reinforced composite sleeve arrestors are particularly suited for retrofitting purposes. This study develops a validated fluid–structure interaction (FSI) framework based on the coupled Eulerian–Lagrangian method to systematically investigate the performance of steel and composite sleeve arrestors in CO2 pipelines. A high-fidelity three-dimensional numerical model is constructed in Abaqus/Explicit to couple crack propagation with CO2 decompression. The Johnson–Cook model is used to characterize fracture in steel; the intralaminar fiber–matrix damage in the composite is modeled using the Hashin criterion, and interfacial debonding in the adhesive layer is modeled using a cohesive zone model. The GERG-2008 equation of state is adopted to model the thermodynamic behavior of CO2 decompression under isentropic, homogeneous equilibrium assumptions. Parametric analyses are performed to examine the influence of the sleeve material, geometric attributes, fitting conditions, and bonding configuration on the effectiveness of crack arrestors. This work contributes to a mechanistic understanding of sleeve-based crack arrestors and demonstrates the utility of advanced FSI modeling in guiding the deployment and optimization of fracture control strategies for CO2 pipeline systems.
{"title":"Comparative study of composite and steel sleeve crack arrestors for mitigating running ductile fracture in CO2 pipelines using fluid-structure interaction analyses","authors":"Jinglue Hu , Jidong Kang , Wenxing Zhou","doi":"10.1016/j.engfracmech.2026.112008","DOIUrl":"10.1016/j.engfracmech.2026.112008","url":null,"abstract":"<div><div>Running ductile fracture is a severe failure mode of dense-phase carbon dioxide (CO<sub>2</sub>) pipelines due to the sustained high crack-driving force associated with CO<sub>2</sub> decompression. Crack arrestors have emerged as a viable option for fracture control; externally mounted steel and fiber reinforced composite sleeve arrestors are particularly suited for retrofitting purposes. This study develops a validated fluid–structure interaction (FSI) framework based on the coupled Eulerian–Lagrangian method to systematically investigate the performance of steel and composite sleeve arrestors in CO<sub>2</sub> pipelines. A high-fidelity three-dimensional numerical model is constructed in Abaqus/Explicit to couple crack propagation with CO<sub>2</sub> decompression. The Johnson–Cook model is used to characterize fracture in steel; the intralaminar fiber–matrix damage in the composite is modeled using the Hashin criterion, and interfacial debonding in the adhesive layer is modeled using a cohesive zone model. The GERG-2008 equation of state is adopted to model the thermodynamic behavior of CO<sub>2</sub> decompression under isentropic, homogeneous equilibrium assumptions. Parametric analyses are performed to examine the influence of the sleeve material, geometric attributes, fitting conditions, and bonding configuration on the effectiveness of crack arrestors. This work contributes to a mechanistic understanding of sleeve-based crack arrestors and demonstrates the utility of advanced FSI modeling in guiding the deployment and optimization of fracture control strategies for CO<sub>2</sub> pipeline systems.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 112008"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387346","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 : 2026-05-02Epub Date: 2026-03-02DOI: 10.1016/j.engfracmech.2026.112009
Zhiqiang Hou , Boyuan Liu , Ruifu Yuan , Yu Wang , Ji Ma , Qingqing Wu
Tensile fracturing is a primary failure mode in the initiation and development of rock mass collapses. Investigating the acoustic emission characteristics and fracture evolution mechanisms of layered rocks under tensile failure, and identifying precursor information of instability, is of great significance for monitoring and early warning of rock mass collapses. Direct tensile tests integrating DIC and AE techniques were conducted on specimens with different bedding inclinations. Results indicate that tensile strength increases by 48.2% with bedding inclination. As the bedding inclination increases, the proportion of tensile cracks first decreases and then increases, reaching its lowest point at β = 45°. k-means clustering classified AE signals during tensile fracture into three clusters: Cluster I, Cluster II and Cluster III; in the final loading stage, Cluster III signals densify, indicating main-crack penetration and serving as a critical precursor to rock failure. The evolution cloud map of the Eyy field reveals the complete process of crack initiation, propagation, and coalescence: For β = 0°–30°, cracks propagate along the weak bedding planes; For β = 45°, cracks partially propagate along the bedding planes and partially through the rock matrix; For β = 60°–90°, cracks primarily propagate within the matrix and penetrate the bedding planes. Based on microscopic fracture mechanisms, tensile fracture surfaces can be classified Cleavage Fracture, Intergranular Fracture and Transgranular Fracture. As the bedding inclination increases, the failure mode shifts from predominantly tensile to a tensile-local shear mixed failure; the fracture surface roughness first rises and then falls, the fracture energy grows exponentially, and the dissipated strain energy shows a slow increase.
{"title":"Anisotropic characteristics and fracture mechanism of direct tensile fractures in layered rock masses","authors":"Zhiqiang Hou , Boyuan Liu , Ruifu Yuan , Yu Wang , Ji Ma , Qingqing Wu","doi":"10.1016/j.engfracmech.2026.112009","DOIUrl":"10.1016/j.engfracmech.2026.112009","url":null,"abstract":"<div><div>Tensile fracturing is a primary failure mode in the initiation and development of rock mass collapses. Investigating the acoustic emission characteristics and fracture evolution mechanisms of layered rocks under tensile failure, and identifying precursor information of instability, is of great significance for monitoring and early warning of rock mass collapses. Direct tensile tests integrating DIC and AE techniques were conducted on specimens with different bedding inclinations. Results indicate that tensile strength increases by 48.2% with bedding inclination. As the bedding inclination increases, the proportion of tensile cracks first decreases and then increases, reaching its lowest point at <em>β</em> = 45°. <em>k</em>-means clustering classified AE signals during tensile fracture into three clusters: Cluster I, Cluster II and Cluster III; in the final loading stage, Cluster III signals densify, indicating main-crack penetration and serving as a critical precursor to rock failure. The evolution cloud map of the <em>E</em><sub>yy</sub> field reveals the complete process of crack initiation, propagation, and coalescence: For <em>β</em> = 0°–30°, cracks propagate along the weak bedding planes; For <em>β</em> = 45°, cracks partially propagate along the bedding planes and partially through the rock matrix; For <em>β</em> = 60°–90°, cracks primarily propagate within the matrix and penetrate the bedding planes. Based on microscopic fracture mechanisms, tensile fracture surfaces can be classified Cleavage Fracture, Intergranular Fracture and Transgranular Fracture. As the bedding inclination increases, the failure mode shifts from predominantly tensile to a tensile-local shear mixed failure; the fracture surface roughness first rises and then falls, the fracture energy grows exponentially, and the dissipated strain energy shows a slow increase.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 112009"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387350","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 : 2026-05-02Epub Date: 2026-02-27DOI: 10.1016/j.engfracmech.2026.111986
Christopher Schmandt, Stephan Marzi
A recently developed cohesive zone model for pure peel loading is generalized and extended to arbitrary mixed-mode I+III loading conditions in this paper. The mixed-mode I+III extension is governed by an energy-based interpolation between pure peel and shear. The implementation generally allows for the input of different single mode cohesive laws and the corresponding model parameters are defined separately for peel and shear. The resulting mixed-mode cohesive zone model depends on the strain rate prior to crack propagation and the ratio of thickness to width as the initial geometry of the adhesive layer. The model was implemented into an user-defined subroutine of a commercial finite element code and used to successfully describe mixed-mode I+III fracture mechanics experiments at various mixed-mode ratios and strain rates on an elastomeric, flexible adhesive. It was found that there was a significant difference between peel mode I and shear mode III only in the shape of the cohesive law and the initial stiffness, while the fracture energy and the cohesive strength were largely independent of the loading mode. This fact supports the assumption that the fracture process is similar in crack opening modes I and III and peel always dominates under large deformations that occur in elastomeric thick adhesive layers. Therefore, calibrating the mixed-mode model using only peel tests can be a permissible simplification in this case, especially regarding industrial applications.
{"title":"Application of a rate-dependent peel fracture cohesive zone model to simulate mixed-mode I+III fracture mechanics experiments on flexible adhesive layers","authors":"Christopher Schmandt, Stephan Marzi","doi":"10.1016/j.engfracmech.2026.111986","DOIUrl":"10.1016/j.engfracmech.2026.111986","url":null,"abstract":"<div><div>A recently developed cohesive zone model for pure peel loading is generalized and extended to arbitrary mixed-mode I+III loading conditions in this paper. The mixed-mode I+III extension is governed by an energy-based interpolation between pure peel and shear. The implementation generally allows for the input of different single mode cohesive laws and the corresponding model parameters are defined separately for peel and shear. The resulting mixed-mode cohesive zone model depends on the strain rate prior to crack propagation and the ratio of thickness to width as the initial geometry of the adhesive layer. The model was implemented into an user-defined subroutine of a commercial finite element code and used to successfully describe mixed-mode I+III fracture mechanics experiments at various mixed-mode ratios and strain rates on an elastomeric, flexible adhesive. It was found that there was a significant difference between peel mode I and shear mode III only in the shape of the cohesive law and the initial stiffness, while the fracture energy and the cohesive strength were largely independent of the loading mode. This fact supports the assumption that the fracture process is similar in crack opening modes I and III and peel always dominates under large deformations that occur in elastomeric thick adhesive layers. Therefore, calibrating the mixed-mode model using only peel tests can be a permissible simplification in this case, especially regarding industrial applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 111986"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387402","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 : 2026-05-02Epub Date: 2026-02-28DOI: 10.1016/j.engfracmech.2026.112000
Jintao He , Ziqi Gao , Yu Xiang , Junyu Chen , Guo Yang , Bin Xi , Dong Lei , Haitao Zhao
Interfacial transition zone (ITZ) is a critical weak link between aggregate and mortar, significantly influences the overall fracture behavior and mechanical performance of concrete. However, the fracture behavior of ITZ is difficult to measure, so that simulation lacks reliable parameters. This study investigates the fracture performance of ITZ by microscale three-point bending test using scanning electron microscopy (SEM) and digital image correlation (DIC), revealing localized deformation and microcrack evolution in ITZ. Wavelet packet analysis enhances maximum principal strain analyzed by DIC to quantify micro-damage before failure stage. Phase-field fracture model is developed to simulate ITZ-driven crack propagation in concrete, incorporating experimentally measured ITZ parameters. Results show that ITZ defects drive early microcrack nucleation, leading to brittle macroscopic failure. The fracture energy Gf of ITZ is determined as 0.02969 N/mm, reflecting its low toughness due to high porosity and weak bonding. The fracture process zone (FPZ) of ITZ can be characterized by regions with high wavelet packet signal energy, which is consistent with results analyzed by DIC. Simulations neglecting ITZ effects overestimate toughness, indicating the critical role of ITZ in post-peak behavior. The integration of SEM-DIC, wavelet packet analysis, and phase-field fracture model provides mechanistic insights into the interplay between the microscale fracture behavior of ITZ and the macroscopic response of concrete.
{"title":"Microscale fracture analysis of concrete interfacial transition zone based on digital image correlation","authors":"Jintao He , Ziqi Gao , Yu Xiang , Junyu Chen , Guo Yang , Bin Xi , Dong Lei , Haitao Zhao","doi":"10.1016/j.engfracmech.2026.112000","DOIUrl":"10.1016/j.engfracmech.2026.112000","url":null,"abstract":"<div><div>Interfacial transition zone (ITZ) is a critical weak link between aggregate and mortar, significantly influences the overall fracture behavior and mechanical performance of concrete. However, the fracture behavior of ITZ is difficult to measure, so that simulation lacks reliable parameters. This study investigates the fracture performance of ITZ by microscale three-point bending test using scanning electron microscopy (SEM) and digital image correlation (DIC), revealing localized deformation and microcrack evolution in ITZ. Wavelet packet analysis enhances maximum principal strain analyzed by DIC to quantify micro-damage before failure stage. Phase-field fracture model is developed to simulate ITZ-driven crack propagation in concrete, incorporating experimentally measured ITZ parameters. Results show that ITZ defects drive early microcrack nucleation, leading to brittle macroscopic failure. The fracture energy <em>G<sub>f</sub></em> of ITZ is determined as 0.02969 N/mm, reflecting its low toughness due to high porosity and weak bonding. The fracture process zone (FPZ) of ITZ can be characterized by regions with high wavelet packet signal energy, which is consistent with results analyzed by DIC. Simulations neglecting ITZ effects overestimate toughness, indicating the critical role of ITZ in post-peak behavior. The integration of SEM-DIC, wavelet packet analysis, and phase-field fracture model provides mechanistic insights into the interplay between the microscale fracture behavior of ITZ and the macroscopic response of concrete.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 112000"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387403","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 : 2026-05-02Epub Date: 2026-02-26DOI: 10.1016/j.engfracmech.2026.111980
A. Fau , A.A. Basmaji , C. Ecker , U. Nackenhorst , R. Desmorat
Random initial damage can be described as isotropic, meaning that a random scalar value is employed to represent the uncertain initial state of damage. The prior pattern of micro-cracking at a point of an existing building or infrastructure, i.e., the initial damage, is oriented by an uncertain, mostly repeated, preload. Damage in such engineering structures shall therefore be considered as anisotropic and represented by a tensorial variable, in the form of a symmetric second-order tensor for the sake of practicality. In case of anisotropic damage, we formulate the uncertain initial damage in a probabilistic framework, in two steps: a probabilistic description of the tensor in its principal basis and a probabilistic orientation of its principal basis. The effect of random initial damage on the tensile response of a quasi-brittle material, such as concrete, is quantified on the peak stress and various post-peak quantities of interest, using Random Continuum Damage Mechanics. The probabilistic response of the anisotropic damage model is computed, and the cumulative distribution functions of the quantities of interest are computed and analyzed. The way the anisotropy and misorientation of the principal basis of the initial damage tensor affect the uncertain mechanical response is quantified. Misorientation is particularly influential for uniaxial initial damage.
{"title":"Random anisotropic initial damage tensor","authors":"A. Fau , A.A. Basmaji , C. Ecker , U. Nackenhorst , R. Desmorat","doi":"10.1016/j.engfracmech.2026.111980","DOIUrl":"10.1016/j.engfracmech.2026.111980","url":null,"abstract":"<div><div>Random initial damage can be described as isotropic, meaning that a random scalar value is employed to represent the uncertain initial state of damage. The prior pattern of micro-cracking at a point of an existing building or infrastructure, <em>i.e.</em>, the initial damage, is oriented by an uncertain, mostly repeated, preload. Damage in such engineering structures shall therefore be considered as anisotropic and represented by a tensorial variable, in the form of a symmetric second-order tensor for the sake of practicality. In case of anisotropic damage, we formulate the uncertain initial damage in a probabilistic framework, in two steps: <span><math><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></math></span> a probabilistic description of the tensor in its principal basis and <span><math><mrow><mo>(</mo><mi>i</mi><mi>i</mi><mo>)</mo></mrow></math></span> a probabilistic orientation of its principal basis. The effect of random initial damage on the tensile response of a quasi-brittle material, such as concrete, is quantified on the peak stress and various post-peak quantities of interest, using Random Continuum Damage Mechanics. The probabilistic response of the anisotropic damage model is computed, and the cumulative distribution functions of the quantities of interest are computed and analyzed. The way the anisotropy and misorientation of the principal basis of the initial damage tensor affect the uncertain mechanical response is quantified. Misorientation is particularly influential for uniaxial initial damage.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 111980"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387341","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}
Unlike the cast AlSi10Mg, the microstructure of laser powder bed fusion additive-manufactured (LPBF-AM) AlSi10Mg is characterized to be a Si phase distributed in a gradient eutectic network, comprising finer, coarser, and discontinuous regions embedded in the aluminium solid solution matrix. The present study investigates the quasi-static compressive deformation behaviour of LPBF-AM AlSi10Mg under varying strain rates ( ) and temperatures (30 250 °C). It was observed that the coarser network near the discontinuous region sustained partial damage during deformation, with the damage size matching that of the discontinuous region due to the larger aspect ratio and fragile nature of the Si phase. The extent of damage increases linearly with strain rate and strain at room temperature but decreases with increasing temperature. Utilizing the cues from a phenomenological model for the cast AlSiMg alloy, the stress at the particle–matrix interface was estimated within the investigated range of strain rate and temperature, while incorporating the critical deformed microstructural observations. The estimated stress closely matches the experimentally observed damage trend, with the strain gradient during deformation driving this behaviour. A plausible damage mechanism for LPBF-AM AlSi10Mg under quasi-static compression is proposed by correlating the deformed microstructures with the model comprising mechanical data.
{"title":"Critical assessment of temperature-dependent compressive deformation behaviour and damage evolution in additively manufactured AlSi10Mg","authors":"Ranjith Kumar Ilangovan , Murugaiyan Amirthalingam , Hariharan Krishnaswamy , Ravi Sankar Kottada","doi":"10.1016/j.engfracmech.2026.111992","DOIUrl":"10.1016/j.engfracmech.2026.111992","url":null,"abstract":"<div><div>Unlike the cast AlSi10Mg, the microstructure of laser powder bed fusion additive-manufactured (LPBF-AM) AlSi10Mg is characterized to be a Si phase distributed in a gradient eutectic network, comprising finer, coarser, and discontinuous regions embedded in the aluminium solid solution matrix. The present study investigates the quasi-static compressive deformation behaviour of LPBF-AM AlSi10Mg under varying strain rates (<span><math><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>-</mo><mn>4</mn></mrow></msup><mo>-</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup></mrow></math></span> <span><math><msup><mrow><mi>s</mi></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup></math></span>) and temperatures (30 <span><math><mo>-</mo></math></span> 250 °C). It was observed that the coarser network near the discontinuous region sustained partial damage during deformation, with the damage size matching that of the discontinuous region due to the larger aspect ratio and fragile nature of the Si phase. The extent of damage increases linearly with strain rate and strain at room temperature but decreases with increasing temperature. Utilizing the cues from a phenomenological model for the cast AlSiMg alloy, the stress at the particle–matrix interface was estimated within the investigated range of strain rate and temperature, while incorporating the critical deformed microstructural observations. The estimated stress closely matches the experimentally observed damage trend, with the strain gradient during deformation driving this behaviour. A plausible damage mechanism for LPBF-AM AlSi10Mg under quasi-static compression is proposed by correlating the deformed microstructures with the model comprising mechanical data.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 111992"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387336","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 : 2026-05-02Epub Date: 2026-03-01DOI: 10.1016/j.engfracmech.2026.112001
Hao Zhang , Binghan Huang , Yubo Bian , Yueyang Li , Chang Ye , Yalin Dong
Additive manufacturing technology has garnered significant attention and experienced rapid development in industrial manufacturing in recent years. Aluminum alloys, widely used in aerospace and automotive sectors, are ideal candidates for laser metal additive manufacturing (AM). However, the additive manufacturing process introduces defects and tensile residual stresses, leading to a decline in fatigue properties of the alloy. In this study, laser shock peening (LSP) was employed to modify the surface of AlSi10Mg alloy fabricated by direct metal laser sintering (DMLS) to tailor its surface integrity and fatigue performance, with mechanically polished samples used for comparison. After LSP treatment, the surface hardness of the alloy increased from 132.8 HV to 157.5 HV. Moreover, the tensile residual stress generated during rapid cooling was effectively transformed into compressive residual stress on the surface. As a combined effect of enhanced hardness and residual stress conversion, the rotary bending fatigue life of the alloy was improved by 1.8–2.8 times under applied stress levels of 40–140 MPa. Although polishing yielded a smoother surface, it provided only limited improvement in fatigue performance. These findings demonstrate that the mechanical properties of additively manufactured AlSi10Mg alloys can be significantly optimized through LSP.
{"title":"Tailoring the surface integrity and fatigue performance of 3D-printed AlSi10Mg alloy through laser shock peening","authors":"Hao Zhang , Binghan Huang , Yubo Bian , Yueyang Li , Chang Ye , Yalin Dong","doi":"10.1016/j.engfracmech.2026.112001","DOIUrl":"10.1016/j.engfracmech.2026.112001","url":null,"abstract":"<div><div>Additive manufacturing technology has garnered significant attention and experienced rapid development in industrial manufacturing in recent years. Aluminum alloys, widely used in aerospace and automotive sectors, are ideal candidates for laser metal additive manufacturing (AM). However, the additive manufacturing process introduces defects and tensile residual stresses, leading to a decline in fatigue properties of the alloy. In this study, laser shock peening (LSP) was employed to modify the surface of AlSi10Mg alloy fabricated by direct metal laser sintering (DMLS) to tailor its surface integrity and fatigue performance, with mechanically polished samples used for comparison. After LSP treatment, the surface hardness of the alloy increased from 132.8 HV to 157.5 HV. Moreover, the tensile residual stress generated during rapid cooling was effectively transformed into compressive residual stress on the surface. As a combined effect of enhanced hardness and residual stress conversion, the rotary bending fatigue life of the alloy was improved by 1.8–2.8 times under applied stress levels of 40–140 MPa. Although polishing yielded a smoother surface, it provided only limited improvement in fatigue performance. These findings demonstrate that the mechanical properties of additively manufactured AlSi10Mg alloys can be significantly optimized through LSP.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 112001"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387339","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 : 2026-05-02Epub Date: 2026-03-01DOI: 10.1016/j.engfracmech.2026.111995
Chengxuan Li, Cunliang Pan, Yisong Qiu, Hongfei Ye, Yonggang Zheng
This study presents a stabilized chemo-mechanical peridynamic model solved implicitly (ISCMPD) to address swelling and fracture in nearly incompressible hyperelastic materials. Utilizing the multiplicative decomposition of the deformation gradient, the total deformation is decomposed into a free swelling component induced by solvent diffusion and an elastic component accounting for the geometric constraint response. To describe the transient swelling process, the classical solvent diffusion equation in continuum mechanics is reformulated into a nonlocal form within the peridynamic framework. Subsequently, a stiffness-scaled penalty term based on dilatation micromodulus is introduced to mitigate numerical oscillations arising from the non-uniform chemical potential scalar state. Additionally, an incremental iterative numerical scheme integrating the Newton-Raphson algorithm with the backward Euler method is proposed to address the system’s nonlinear behavior. The stability and robustness of the proposed ISCMPD model are demonstrated through representative numerical examples. Finally, numerical results from both tensile fracture tests on pre-swollen plates and deswelling-driven fracture tests under fixed displacement validate the reliability and applicability of the proposed method for predicting complex fracture behaviors in chemo-mechanical coupled systems.
{"title":"An implicit stabilized peridynamic model for swelling-induced fracture in nearly incompressible hyperelastic materials","authors":"Chengxuan Li, Cunliang Pan, Yisong Qiu, Hongfei Ye, Yonggang Zheng","doi":"10.1016/j.engfracmech.2026.111995","DOIUrl":"10.1016/j.engfracmech.2026.111995","url":null,"abstract":"<div><div>This study presents a stabilized chemo-mechanical peridynamic model solved implicitly (ISCMPD) to address swelling and fracture in nearly incompressible hyperelastic materials. Utilizing the multiplicative decomposition of the deformation gradient, the total deformation is decomposed into a free swelling component induced by solvent diffusion and an elastic component accounting for the geometric constraint response. To describe the transient swelling process, the classical solvent diffusion equation in continuum mechanics is reformulated into a nonlocal form within the peridynamic framework. Subsequently, a stiffness-scaled penalty term based on dilatation micromodulus is introduced to mitigate numerical oscillations arising from the non-uniform chemical potential scalar state. Additionally, an incremental iterative numerical scheme integrating the Newton-Raphson algorithm with the backward Euler method is proposed to address the system’s nonlinear behavior. The stability and robustness of the proposed ISCMPD model are demonstrated through representative numerical examples. Finally, numerical results from both tensile fracture tests on pre-swollen plates and deswelling-driven fracture tests under fixed displacement validate the reliability and applicability of the proposed method for predicting complex fracture behaviors in chemo-mechanical coupled systems.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"337 ","pages":"Article 111995"},"PeriodicalIF":5.3,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387340","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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