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A spatiotemporal deep learning framework for prediction of crack dynamics in heterogeneous solids: Efficient mapping of concrete microstructures to its fracture properties
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110675
Rasoul Najafi Koopas , Shahed Rezaei , Natalie Rauter , Richard Ostwald , Rolf Lammering
A spatiotemporal deep learning framework is proposed that is capable of two-dimensional full-field prediction of fracture in concrete mesostructures. This framework not only predicts fractures but also captures the entire history of the fracture process, from the crack initiation in the interfacial transition zone (ITZ) to the subsequent propagation of the cracks in the mortar matrix. Additionally, a convolutional neural network (CNN) is developed which is capable of predicting the averaged stress–strain curve of the mesostructures. The UNet modeling framework, which comprises an encoder–decoder section with skip connections, is used as the deep learning surrogate model. Training and test data are generated from high-fidelity fracture simulations of randomly generated concrete mesostructures. These mesostructures include geometric variabilities such as different aggregate particle geometrical features, spatial distribution, and the total volume fraction of aggregates. The fracture simulations are carried out in Abaqus/CAE, utilizing the cohesive phase-field fracture modeling technique as the fracture modeling approach. In this work, to reduce the number of training datasets, the spatial distribution of three sets of material properties for three-phase concrete mesostructures, along with the spatial phase-field damage index, are fed to the UNet to predict the corresponding stress and spatial damage index at the subsequent step. It is shown that after the training process using this methodology, the UNet model is capable of accurately predicting damage on the unseen test dataset by using just 470 datasets. Moreover, another novel aspect of this work is the conversion of irregular finite element data into regular grids using a developed pipeline. This approach allows for the implementation of less complex UNet architecture and facilitates the integration of phase-field fracture equations into surrogate models for future developments.
{"title":"A spatiotemporal deep learning framework for prediction of crack dynamics in heterogeneous solids: Efficient mapping of concrete microstructures to its fracture properties","authors":"Rasoul Najafi Koopas ,&nbsp;Shahed Rezaei ,&nbsp;Natalie Rauter ,&nbsp;Richard Ostwald ,&nbsp;Rolf Lammering","doi":"10.1016/j.engfracmech.2024.110675","DOIUrl":"10.1016/j.engfracmech.2024.110675","url":null,"abstract":"<div><div>A spatiotemporal deep learning framework is proposed that is capable of two-dimensional full-field prediction of fracture in concrete mesostructures. This framework not only predicts fractures but also captures the entire history of the fracture process, from the crack initiation in the interfacial transition zone (ITZ) to the subsequent propagation of the cracks in the mortar matrix. Additionally, a convolutional neural network (CNN) is developed which is capable of predicting the averaged stress–strain curve of the mesostructures. The UNet modeling framework, which comprises an encoder–decoder section with skip connections, is used as the deep learning surrogate model. Training and test data are generated from high-fidelity fracture simulations of randomly generated concrete mesostructures. These mesostructures include geometric variabilities such as different aggregate particle geometrical features, spatial distribution, and the total volume fraction of aggregates. The fracture simulations are carried out in Abaqus/CAE, utilizing the cohesive phase-field fracture modeling technique as the fracture modeling approach. In this work, to reduce the number of training datasets, the spatial distribution of three sets of material properties for three-phase concrete mesostructures, along with the spatial phase-field damage index, are fed to the UNet to predict the corresponding stress and spatial damage index at the subsequent step. It is shown that after the training process using this methodology, the UNet model is capable of accurately predicting damage on the unseen test dataset by using just 470 datasets. Moreover, another novel aspect of this work is the conversion of irregular finite element data into regular grids using a developed pipeline. This approach allows for the implementation of less complex UNet architecture and facilitates the integration of phase-field fracture equations into surrogate models for future developments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110675"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The dominating dimensionless numbers of adiabatic shear localization
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110724
Zhi-yong Yin , Xiao-wei Chen
Adiabatic shear is a complex phenomenon involving thermo-mechanical coupled failure mechanisms, which is affected by material properties, loads, and geometries. In this study, four dimensionless numbers which only contain input parameters and can fully reflect the influence of adiabatic shear are determined by reducing the conservation equations of shear localization to dimensionless terms. The dimensional analysis method of adiabatic shear, along with predictive models for the characteristic parameters of adiabatic shear, are systematically provided by revealing the physical significance of the dimensionless numbers. Based on data analysis, a dimensional analysis method of adiabatic shear for multi-physical processes is proposed, which has been successfully applied to explosively-driven metal shells, to realize the prediction and control of adiabatic shear. This study demonstrates that the prediction models of adiabatic shear-band spacing and width can be unified through a relationship involving the Prandtl number, Pr. Furthermore, the classical prediction models of spacing and width are improved based on the experimental data. It is clearly pointed out that the more favorable the formation of shear localization, the smaller the width and spacing of the shear band, which illustrates the influence of material properties and loads on the spatial distribution of shear bands. In addition, a new prediction model for the propagation velocity of the shear band including Pr is proposed by using dimensional analysis. Compared with the classical model, the new model has higher accuracy, and can correctly reflect the influence of loads, material mechanical and thermophysical properties on the shear-band velocity.
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引用次数: 0
Dynamic mechanical response and failure behaviour of single-flawed rocks under combined compression-shear loading
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110777
Zhi Cai , Feng Dai , Zelin Yan , Yi Liu , Biao Zhang , Mingdong Wei
In deep underground engineering projects, flawed rocks are often subjected to dynamic compression-shear loading owing to the arbitrary distribution of structural planes in rock mass. Understanding the dynamic mechanical response of flawed rocks under compression-shear loading is of great significance for rock engineering construction. In this study, the mechanical response and failure behaviors of flawed rock specimens subjected to dynamic compression-shear loading are studied by introducing an oblique cubic flawed specimen into the split Hopkinson pressure bar (SHPB) tests. Firstly, the stress distribution of the oblique flawed specimen is analyzed by using the finite element method. Numerical results show that the stress concentration zones are distributed along the short diagonal of oblique rock specimens, which validates the oblique specimen is an effective method to investigate the dynamic compression-shear failure behaviors of flawed rocks. Then, dynamic impact tests are conducted on oblique flawed rocks with different configurations. The experimental results indicate that the oblique angle, the flaw inclination angle, and the strain rate significantly affect the dynamic strength and deformation characteristics of the rock. Utilizing high-speed digital image correlation (DIC), the progressive cracking behavior and failure modes of flawed rocks under dynamic compression-shear loading are analyzed. The mixed compression-shear cracking dominates the failure of flawed rock specimens. In addition, the energy dissipation density and fragmentation degree also exhibit a strong strain rate dependency, and they are positively correlated with the dynamic strength of the flawed rocks.
{"title":"Dynamic mechanical response and failure behaviour of single-flawed rocks under combined compression-shear loading","authors":"Zhi Cai ,&nbsp;Feng Dai ,&nbsp;Zelin Yan ,&nbsp;Yi Liu ,&nbsp;Biao Zhang ,&nbsp;Mingdong Wei","doi":"10.1016/j.engfracmech.2024.110777","DOIUrl":"10.1016/j.engfracmech.2024.110777","url":null,"abstract":"<div><div>In deep underground engineering projects, flawed rocks are often subjected to dynamic compression-shear loading owing to the arbitrary distribution of structural planes in rock mass. Understanding the dynamic mechanical response of flawed rocks under compression-shear loading is of great significance for rock engineering construction. In this study, the mechanical response and failure behaviors of flawed rock specimens subjected to dynamic compression-shear loading are studied by introducing an oblique cubic flawed specimen into the split Hopkinson pressure bar (SHPB) tests. Firstly, the stress distribution of the oblique flawed specimen is analyzed by using the finite element method. Numerical results show that the stress concentration zones are distributed along the short diagonal of oblique rock specimens, which validates the oblique specimen is an effective method to investigate the dynamic compression-shear failure behaviors of flawed rocks. Then, dynamic impact tests are conducted on oblique flawed rocks with different configurations. The experimental results indicate that the oblique angle, the flaw inclination angle, and the strain rate significantly affect the dynamic strength and deformation characteristics of the rock. Utilizing high-speed digital image correlation (DIC), the progressive cracking behavior and failure modes of flawed rocks under dynamic compression-shear loading are analyzed. The mixed compression-shear cracking dominates the failure of flawed rock specimens. In addition, the energy dissipation density and fragmentation degree also exhibit a strong strain rate dependency, and they are positively correlated with the dynamic strength of the flawed rocks.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110777"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of complex stress states on creep rupture life of nickel-based superalloys: Mechanisms and modeling
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110749
Sui Tianxiao , Zhang Yuman , Xiang Shouliang , Shi Duoqi
This study investigates the effects of complex stress states on creep rupture life of nickel-based superalloys. Creep experiments were conducted at 900 °C on both smooth and single-hole plate specimens. A viscoplastic constitutive model was developed to simulate the creep behavior of single-hole plates and V-notched bars. The analysis offered a detailed mechanical explanation for the significant differences in creep rupture life observed among these differently structured specimens. This investigation incorporated the effects of complex stress states into the Monkman-Grant relationship, resulting in a new creep life model that accounts for stress triaxiality. The results indicate that the increased stress triaxiality significantly extends the creep life of V-notched bars. In contrast, the single-hole plates, which approach a uniaxial stress state, exhibit a creep rupture life closely aligning with that of the standard smooth plates. The proposed model accurately predicts the creep rupture life of both single-hole plates and V-notched bars, with all predictions falling within a threefold scatter band.
{"title":"Effect of complex stress states on creep rupture life of nickel-based superalloys: Mechanisms and modeling","authors":"Sui Tianxiao ,&nbsp;Zhang Yuman ,&nbsp;Xiang Shouliang ,&nbsp;Shi Duoqi","doi":"10.1016/j.engfracmech.2024.110749","DOIUrl":"10.1016/j.engfracmech.2024.110749","url":null,"abstract":"<div><div>This study investigates the effects of complex stress states on creep rupture life of nickel-based superalloys. Creep experiments were conducted at 900 °C on both smooth and single-hole plate specimens. A viscoplastic constitutive model was developed to simulate the creep behavior of single-hole plates and V-notched bars. The analysis offered a detailed mechanical explanation for the significant differences in creep rupture life observed among these differently structured specimens. This investigation incorporated the effects of complex stress states into the Monkman-Grant relationship, resulting in a new creep life model that accounts for stress triaxiality. The results indicate that the increased stress triaxiality significantly extends the creep life of V-notched bars. In contrast, the single-hole plates, which approach a uniaxial stress state, exhibit a creep rupture life closely aligning with that of the standard smooth plates. The proposed model accurately predicts the creep rupture life of both single-hole plates and V-notched bars, with all predictions falling within a threefold scatter band.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110749"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Experimental and numerical investigation of groove-assisted impact rock-breaking
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110769
Zhengkuo Ma , Chunshun Zhang , Zenghui Liu , Tong Ye , Congying Li , Wei Wei , Jie Dong
Groove-assisted impact rock-breaking represents a critical mechanical method for fracturing rocks; however, comprehending its underlying mechanisms governing fracture initiation and propagation remains incomplete. This paper aims to fill this knowledge gap by first establishing a dedicated test bench for groove-assisted impact rock-breaking and conducting double-impact head experiments with varying spacings. Subsequently, a finite discrete element method (FDEM) model is developed, incorporating zero-thickness cohesive elements, to validate and refine the numerical simulations against experimental outcomes. The investigation then systematically explores the impacts of double-head and multi-head rock-breaking to elucidate the dynamic evolution of stress fields and damage processes throughout the rock-breaking sequence. This includes the formation of dense cores, the initiation and propagation of fractures, and the eventual propagation of splitting damage. Noteworthy findings of this study include the identification and characterization of four distinct damage zones: an intermediate impact breakage zone dominated by shear damage, an annular extrusion damage zone typified by tensile failure, a primary surface cracking damage zone, and an interconnecting damage zone between dual impact heads, both characterized by tensile damage. Additionally, the study examines variations in penetration depth relative to the number and positioning of impact heads under conditions of equal energy input. These insights significantly enhance our understanding of the fracture mechanics involved in groove-assisted impact rock-breaking and lay the groundwork for enhancing rock-breaking efficiency.
{"title":"Experimental and numerical investigation of groove-assisted impact rock-breaking","authors":"Zhengkuo Ma ,&nbsp;Chunshun Zhang ,&nbsp;Zenghui Liu ,&nbsp;Tong Ye ,&nbsp;Congying Li ,&nbsp;Wei Wei ,&nbsp;Jie Dong","doi":"10.1016/j.engfracmech.2024.110769","DOIUrl":"10.1016/j.engfracmech.2024.110769","url":null,"abstract":"<div><div>Groove-assisted impact rock-breaking represents a critical mechanical method for fracturing rocks; however, comprehending its underlying mechanisms governing fracture initiation and propagation remains incomplete. This paper aims to fill this knowledge gap by first establishing a dedicated test bench for groove-assisted impact rock-breaking and conducting double-impact head experiments with varying spacings. Subsequently, a finite discrete element method (FDEM) model is developed, incorporating zero-thickness cohesive elements, to validate and refine the numerical simulations against experimental outcomes. The investigation then systematically explores the impacts of double-head and multi-head rock-breaking to elucidate the dynamic evolution of stress fields and damage processes throughout the rock-breaking sequence. This includes the formation of dense cores, the initiation and propagation of fractures, and the eventual propagation of splitting damage. Noteworthy findings of this study include the identification and characterization of four distinct damage zones: an intermediate impact breakage zone dominated by shear damage, an annular extrusion damage zone typified by tensile failure, a primary surface cracking damage zone, and an interconnecting damage zone between dual impact heads, both characterized by tensile damage. Additionally, the study examines variations in penetration depth relative to the number and positioning of impact heads under conditions of equal energy input. These insights significantly enhance our understanding of the fracture mechanics involved in groove-assisted impact rock-breaking and lay the groundwork for enhancing rock-breaking efficiency.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110769"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Interpretation of uniaxial creep damage properties and rupture life considering local necking via an inverse approach
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110735
M. Li , R.Q. Guo , B. Zhou , X.F. Gong , Z.X. Wen , Z.F. Yue , W. Sun
Tertiary creep-induced local necking, which occurs during uniaxial creep tests for creep-ductile materials, has been a long-term concern in the interpretation of creep rupture life under both constant load and constant stress conditions. In this study, a set of short-term, high stress regime, creep rupture tests, in a range of stress and temperature, for a newly developed tempered martensitic MarBN steel, were used to understand the necking mechanics and the underlying deformation mechanisms. An FE-based, inverse approach is developed to determine the full stage creep damage properties under large deformation conditions, utilizing the measured deformed shapes of local necking within the inverse optimization scheme. On this basis, a temperature-dependent empirical relationship of the creep rupture lives between constant load and constant stress creep rupture tests is established. As a demonstration, the feasibility and accuracy of the proposed relationship was evaluated through a benchmark case using the data from the G115 martensitic steel creep tests. The implications of this relationship for broader and more general conditions (e.g., stress range, temperature, materials) and practical applications are discussed.
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引用次数: 0
Phase field fracture modeling of mechanical degradation and crack propagation in random porous sintered nano-silver with thermal and strain-rate effects
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110753
Xu Long , Jiaqi Zhu , Yutai Su , Yi Yan , Chao Chang , Hongqiang Zhang , Valentina Salomoni
Sintered nano-silver, known for its superior thermal properties, is increasingly vital for dissipating heat in high-power electronic devices. This study explores how temperature (25–200 °C) and strain rates (1 × 10-1–1 × 10-5 s−1) affect the mechanical properties and crack propagation in this material. Experiments and simulations, using shear tests on lap specimens and a phase field fracture model that accounts for energy contributions from temperature and strain rate, reveal significant insights. Below 100 °C, mechanical strength is primarily reduced by temperature softening, with little change in porosity. Above 100 °C, a re-sintering process triggered by thermal energy alters the material’s mesoscopic structure. Despite consistent porosity across tests at various strain rates, an increase in shear strength underlines the material’s sensitivity to strain rate changes. The model further shows that while strain energy remains fairly constant across temperatures, the contribution from thermal energy peaks and then diminishes as temperature rises, inversely affecting shear strength. Conversely, higher strain rates reduce the energy contributions from both strain and rate, decreasing energy-driven fractures and boosting strength. The model successfully predicts crack propagation patterns in tested specimens, validating its effectiveness in assessing the mechanical behavior of sintered nano-silver.
{"title":"Phase field fracture modeling of mechanical degradation and crack propagation in random porous sintered nano-silver with thermal and strain-rate effects","authors":"Xu Long ,&nbsp;Jiaqi Zhu ,&nbsp;Yutai Su ,&nbsp;Yi Yan ,&nbsp;Chao Chang ,&nbsp;Hongqiang Zhang ,&nbsp;Valentina Salomoni","doi":"10.1016/j.engfracmech.2024.110753","DOIUrl":"10.1016/j.engfracmech.2024.110753","url":null,"abstract":"<div><div>Sintered nano-silver, known for its superior thermal properties, is increasingly vital for dissipating heat in high-power electronic devices. This study explores how temperature (25–200 °C) and strain rates (1 × 10<sup>-1</sup>–1 × 10<sup>-5</sup> s<sup>−1</sup>) affect the mechanical properties and crack propagation in this material. Experiments and simulations, using shear tests on lap specimens and a phase field fracture model that accounts for energy contributions from temperature and strain rate, reveal significant insights. Below 100 °C, mechanical strength is primarily reduced by temperature softening, with little change in porosity. Above 100 °C, a re-sintering process triggered by thermal energy alters the material’s mesoscopic structure. Despite consistent porosity across tests at various strain rates, an increase in shear strength underlines the material’s sensitivity to strain rate changes. The model further shows that while strain energy remains fairly constant across temperatures, the contribution from thermal energy peaks and then diminishes as temperature rises, inversely affecting shear strength. Conversely, higher strain rates reduce the energy contributions from both strain and rate, decreasing energy-driven fractures and boosting strength. The model successfully predicts crack propagation patterns in tested specimens, validating its effectiveness in assessing the mechanical behavior of sintered nano-silver.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110753"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A new adaptive peridynamic framework for modeling large deformation and fracture behavior of hyperelastic materials
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110709
D.A. Abdoh
Accurate prediction of deformation and fracture behaviors of hyperelastic materials is crucial in engineering applications and industry. The paper presents a new three-dimensional computational model to simulate large deformations and fractures in hyperelastic materials using the peridynamic method. The main innovation of the proposed three-dimensional hyperelastic peridynamic (3D-HPD) model lies in its incorporation of the stress–strain relationship of hyperelastic materials into the peridynamic framework. Therefore, the peridynamic parameters, such as bond stiffness and strength, are dynamically updated based on the instantaneous value of Young's modulus derived from the stress–strain relation of hyperelastic materials. The 3D-HPD model highlights the following novelties: 1) The 3D-HPD model directly employs the stress–strain relation for each peridynamic bond. Thus, the large deformations and fractures in hyperelastic materials are accurately captured in three dimensions by integrating the responses in all peridynamic bonds; 2) Unlike other models that may require specific hyperelastic formulations, the 3D-HPD model offers a more straightforward application, enhancing usability and reducing complexity; 3) The 3D-HPD model is capable of simulating the response of hyperelastic materials under various loading conditions, including tensile, torsional, and lateral loadings. We confirm the validity of the 3D-HPD model by evaluating it against experimental measurements and observations. For the first time, the model examines hyperelastic materials' fracture and deformation behaviors under combined loading conditions. The new findings of the mechanical performance of hyperelastic materials under multi-axial stresses provide new insights to enhance their design and usage.
{"title":"A new adaptive peridynamic framework for modeling large deformation and fracture behavior of hyperelastic materials","authors":"D.A. Abdoh","doi":"10.1016/j.engfracmech.2024.110709","DOIUrl":"10.1016/j.engfracmech.2024.110709","url":null,"abstract":"<div><div>Accurate prediction of deformation and fracture behaviors of hyperelastic materials is crucial in engineering applications and industry. The paper presents a new three-dimensional computational model to simulate large deformations and fractures in hyperelastic materials using the peridynamic method. The main innovation of the proposed three-dimensional hyperelastic peridynamic (3D-HPD) model lies in its incorporation of the stress–strain relationship of hyperelastic materials into the peridynamic framework. Therefore, the peridynamic parameters, such as bond stiffness and strength, are dynamically updated based on the instantaneous value of Young's modulus derived from the stress–strain relation of hyperelastic materials. The 3D-HPD model highlights the following novelties: 1) The 3D-HPD model directly employs the stress–strain relation for each peridynamic bond. Thus, the large deformations and fractures in hyperelastic materials are accurately captured in three dimensions by integrating the responses in all peridynamic bonds; 2) Unlike other models that may require specific hyperelastic formulations, the 3D-HPD model offers a more straightforward application, enhancing usability and reducing complexity; 3) The 3D-HPD model is capable of simulating the response of hyperelastic materials under various loading conditions, including tensile, torsional, and lateral loadings. We confirm the validity of the 3D-HPD model by evaluating it against experimental measurements and observations. For the first time, the model examines hyperelastic materials' fracture and deformation behaviors under combined loading conditions. The new findings of the mechanical performance of hyperelastic materials under multi-axial stresses provide new insights to enhance their design and usage.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"314 ","pages":"Article 110709"},"PeriodicalIF":4.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On the use of representative specimens for the structural integrity assessment of safety-relevant rotating components
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-07 DOI: 10.1016/j.engfracmech.2024.110710
Jiangchao Zhu , Mauro Madia , Michael Schurig , Julius Kruse , Fabian Conrad , Hartmut Schlums , Christian Kontermann , Uwe Zerbst
Safety-relevant components, for which a failure in service could have catastrophic consequences, are usually designed for extremely low probability of failure and they are subjected to stringent part qualification procedures according to guidelines set by regulatory agencies. Manufacturers are often forced to perform tests on full scale or scaled components to ensure the structural integrity under defined loading conditions, which usually implies a huge experimental and financial effort. Therefore, companies try to develop new strategies such as digital twins, which allow to massively reduce costs, without compromising safety. This work presents a new quasi-static testing and assessment concept, the main idea of which is to replace, or at least reduce, the experimental testing on components by testing specimens representative of the component.
Fracture mechanics specimens have been designed iteratively by numerical simulations to match the stress state at the crack-tip of the maximum permissible defect defined by regulatory agencies for the component. Potentially, the major benefit of the proposed approach is that the tests can be performed on conventional laboratory testing machines. The effectiveness of the methodology is demonstrated in case of the structural integrity assessment of a Ni-base superalloy aero-engine turbine disk at overspeed conditions.
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引用次数: 0
A new dual strengthening strategy to improve the bending resistance of thin-walled bellows using prefabricated martensite and a gradient structure
IF 4.7 2区 工程技术 Q1 MECHANICS Pub Date : 2025-02-05 DOI: 10.1016/j.engfracmech.2025.110902
Meng-ye Wang , Meng Yan , Huan-chao Zhang , Yong Liu , Hua-gui Huang
In order to improve the bending resistance of bellows, in this study, the bellows microstructure was uniquely designed via an induction heat treatment process (IHTP). Thin-walled bellows with a gradient structure and martensite arranged along a preset path were prepared. Using a combination of experimental and material characterization methods, the microstructural characteristics of the matrix and their evolution during the bending process were studied, and the strengthening mechanism of the bending resistance of the IHTP bellows was revealed. The results showed that IHTP could be used to prepare bellows with a gradient grain size distribution (gradually refined along the wave peak toward the trough), increase the content of low-angle grain boundaries (LAGBs), and generate a large amount of lath martensite distributed along the ripple direction. The results of repeated bending testing and fracture morphology analysis showed that the stress of the material was more uniform due to the grain refinement in the trough of the IHTP bellows. Meanwhile, due to the brittleness of martensite, cracks propagated along the preset ripple direction, delaying the propagation of the main crack in the wall thickness direction and improving the bending number of the bellows. The maximum increase in the bending number for the IHTP bellows was nearly 300%, when compared with bellows designed via a general heat treatment process (GHTP). The fracture surface was characterized by small and dense dimples and local deep dimples. Additionally, the crack boundary was more tortuous, indicating that the crack propagation resistance increased, and the fracture form changed from transgranular fracture to intergranular fracture. This study provides a new method for improving the bending resistance of bellows.
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引用次数: 0
期刊
Engineering Fracture Mechanics
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