Pub Date : 2025-02-17DOI: 10.1016/j.mechmat.2025.105300
Jun Wang , Ziwei Ma , Gan Ding , Rong Yang , Songlin Cai , Lanhong Dai , Chunsheng Lu , Minqiang Jiang
It is experimentally difficult to ascertain the role of ferrite/cementite interface in the impact properties and structural evolution of pearlitic steel. In this paper, we propose a solution based on molecular dynamics simulations of planar shocks of pearlitic steel. It is found that the ferrite/cementite interface reflects the part of a shock wave and facilitates the nucleation of voids and dislocations. Consequently, the disturbance and plastic wave details are added to free surface velocity−time profiles. The evolution of voids contributes to the subsequent occurrence of spallation at interface, generating a power law relationship between the tensile strain rate and spall strength with an exponent of 2.7, which differs from that of 4.0 as spallation happens in polycrystalline ferrite regions.
{"title":"Impact response of pearlitic steel dominated by ferrite/cementite interface","authors":"Jun Wang , Ziwei Ma , Gan Ding , Rong Yang , Songlin Cai , Lanhong Dai , Chunsheng Lu , Minqiang Jiang","doi":"10.1016/j.mechmat.2025.105300","DOIUrl":"10.1016/j.mechmat.2025.105300","url":null,"abstract":"<div><div>It is experimentally difficult to ascertain the role of ferrite/cementite interface in the impact properties and structural evolution of pearlitic steel. In this paper, we propose a solution based on molecular dynamics simulations of planar shocks of pearlitic steel. It is found that the ferrite/cementite interface reflects the part of a shock wave and facilitates the nucleation of voids and dislocations. Consequently, the disturbance and plastic wave details are added to free surface velocity−time profiles. The evolution of voids contributes to the subsequent occurrence of spallation at interface, generating a power law relationship between the tensile strain rate and spall strength with an exponent of 2.7, which differs from that of 4.0 as spallation happens in polycrystalline ferrite regions.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"204 ","pages":"Article 105300"},"PeriodicalIF":3.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.mechmat.2025.105297
Akash Raikwar, Sandeep Singh
A computationally efficient numerical simulations based on an atomistic-continuum coupling in conjunction with a finite element model are presented for the static response of graphene sheets under transverse and in-plane compressive loads at finite temperatures. The present multiscale approach incorporates the dihedral energy terms in atomic interactions based on Tersoff-Brenner potential and Green-Lagrange nonlinearity through strain displacement relations. The atomic level deformations (bond lengths, bond angles and dihedral angles) are coupled to continuum scale through the quadratic-type Cauchy Born rule. The governing equations at continuum scale are solved through finite element method. The separate subroutine is developed to calculate stress/moments resultants, and the tangent constitutive matrix is embedded in the Gauss-quadrature numerical integration of the elemental equations. The influence of dihedral energy term and finite temperature on the linear and nonlinear bending response and postbuckling analyses of graphene sheets is investigated in detail. In addition, a new set of empirical parameters proposed by authors in their earlier work has also been examined for the nonlinear response of graphene sheets.
{"title":"A concurrent multiscale simulation for nonlinear flexural and postbuckling analyses of single-layer graphene sheets at finite temperature","authors":"Akash Raikwar, Sandeep Singh","doi":"10.1016/j.mechmat.2025.105297","DOIUrl":"10.1016/j.mechmat.2025.105297","url":null,"abstract":"<div><div>A computationally efficient numerical simulations based on an atomistic-continuum coupling in conjunction with a finite element model are presented for the static response of graphene sheets under transverse and in-plane compressive loads at finite temperatures. The present multiscale approach incorporates the dihedral energy terms in atomic interactions based on Tersoff-Brenner potential and Green-Lagrange nonlinearity through strain displacement relations. The atomic level deformations (bond lengths, bond angles and dihedral angles) are coupled to continuum scale through the quadratic-type Cauchy Born rule. The governing equations at continuum scale are solved through finite element method. The separate subroutine is developed to calculate stress/moments resultants, and the tangent constitutive matrix is embedded in the Gauss-quadrature numerical integration of the elemental equations. The influence of dihedral energy term and finite temperature on the linear and nonlinear bending response and postbuckling analyses of graphene sheets is investigated in detail. In addition, a new set of empirical parameters proposed by authors in their earlier work has also been examined for the nonlinear response of graphene sheets.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"205 ","pages":"Article 105297"},"PeriodicalIF":3.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.mechmat.2025.105292
Milad Shirani , Mircea Bîrsan
In this work, we derive the necessary conditions for stable equilibrium states for fibrous materials and lattice solids. We use Cosserat elasticity to obtain balance laws and boundary conditions by minimizing the total potential energy. Afterward, we find conditions that have to be satisfied by the solutions of the balance laws and boundary conditions. These conditions are quasi-convexity condition, ordinary convexity condition, and Legendre–Hadamard inequalities. For the surfaces of discontinuity, we derive Maxwell–Eshelby relations.
{"title":"Necessary conditions for stable equilibrium states of lattice solids based on the Cosserat elasticity theory","authors":"Milad Shirani , Mircea Bîrsan","doi":"10.1016/j.mechmat.2025.105292","DOIUrl":"10.1016/j.mechmat.2025.105292","url":null,"abstract":"<div><div>In this work, we derive the necessary conditions for stable equilibrium states for fibrous materials and lattice solids. We use Cosserat elasticity to obtain balance laws and boundary conditions by minimizing the total potential energy. Afterward, we find conditions that have to be satisfied by the solutions of the balance laws and boundary conditions. These conditions are quasi-convexity condition, ordinary convexity condition, and Legendre–Hadamard inequalities. For the surfaces of discontinuity, we derive Maxwell–Eshelby relations.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"204 ","pages":"Article 105292"},"PeriodicalIF":3.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-16DOI: 10.1016/j.mechmat.2025.105296
Sui Jia , Hao Zhang , Jidong Yu , Xiaoyang Pei , Songlin Yao , Qiang Wu
Despite significant attention over recent decades, the dynamic plasticity of magnesium (Mg) under high pressure and high strain rates remains far from well understood owing to the complexity of deformation under such extreme conditions. In particular, dynamic twinning plasticity is still described by phenomenological models, which limits further understanding of the dynamic mechanical response of metals. In this work, a twinning substructure model, in which twinning nucleation, propagation, and growth are taken into account, is applied to address plastic deformation of single-crystalline Mg subjected to shock compression. The model is coupled with a dislocation plasticity model under the thermoelastic–viscoplastic framework. By utilizing this combined model, a quantitative connection between the evolution of defects, including dislocations and twins, and the experimentally measured wave profiles is established. Modeling the mechanical response of single-crystalline Mg under shock compression provides new insights into the twinning-related plasticity of Mg, revealing that the typical features of the wave profile of Mg are significantly influenced by twinning, especially those along the (10–10) direction. Notably, in contrast to the classical understanding predicted by the dislocation plasticity model that deformation on the elastic precursor wavefront is purely one-dimensional elastic, the new model indicates that twinning nucleation leads to considerable plastic deformation on the elastic precursor wavefront. Additionally, plasticity along the (10–10) direction at the plastic front is demonstrated to be governed by twinning and dislocation mechanisms acting together, while the power-scaling law appears to be almost independent of the twinning mechanisms.
{"title":"Modeling of shock-induced plasticity of single-crystalline magnesium with a coupled dislocation and twinning constitutive model","authors":"Sui Jia , Hao Zhang , Jidong Yu , Xiaoyang Pei , Songlin Yao , Qiang Wu","doi":"10.1016/j.mechmat.2025.105296","DOIUrl":"10.1016/j.mechmat.2025.105296","url":null,"abstract":"<div><div>Despite significant attention over recent decades, the dynamic plasticity of magnesium (Mg) under high pressure and high strain rates remains far from well understood owing to the complexity of deformation under such extreme conditions. In particular, dynamic twinning plasticity is still described by phenomenological models, which limits further understanding of the dynamic mechanical response of metals. In this work, a twinning substructure model, in which twinning nucleation, propagation, and growth are taken into account, is applied to address plastic deformation of single-crystalline Mg subjected to shock compression. The model is coupled with a dislocation plasticity model under the thermoelastic–viscoplastic framework. By utilizing this combined model, a quantitative connection between the evolution of defects, including dislocations and twins, and the experimentally measured wave profiles is established. Modeling the mechanical response of single-crystalline Mg under shock compression provides new insights into the twinning-related plasticity of Mg, revealing that the typical features of the wave profile of Mg are significantly influenced by twinning, especially those along the (10–10) direction. Notably, in contrast to the classical understanding predicted by the dislocation plasticity model that deformation on the elastic precursor wavefront is purely one-dimensional elastic, the new model indicates that twinning nucleation leads to considerable plastic deformation on the elastic precursor wavefront. Additionally, plasticity along the (10–10) direction at the plastic front is demonstrated to be governed by twinning and dislocation mechanisms acting together, while the power-scaling law appears to be almost independent of the twinning mechanisms.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"204 ","pages":"Article 105296"},"PeriodicalIF":3.4,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-12DOI: 10.1016/j.mechmat.2025.105293
Yanpeng Yue , Yongping Wan , Zheng Zhong
The dynamic effective properties of piezoelectric composites containing inclusions oriented in arbitrary directions are studied using the self-consistent method. The direction angle distribution function is introduced to describe the orientations of inclusions. An interpolation method for calculating the angle average integral is provided. The results of this work show good agreement with other theoretical and experimental results, both for the static and dynamic effective properties. The effect of the volume fraction on the effective phase velocity and attenuation is examined. The influence of the degree of alignment of the inclusions on the effective elastic moduli and resonant frequency is analyzed. The results show that the effects of the shape and orientation of the inclusions, as well as the frequency, act jointly rather than independently. The model will offer theoretical insights into controlling elastic waves in piezoelectric composites by adjusting the orientation of inclusions.
{"title":"Dynamic effective properties of piezoelectric composites with inclusions in arbitrary orientations","authors":"Yanpeng Yue , Yongping Wan , Zheng Zhong","doi":"10.1016/j.mechmat.2025.105293","DOIUrl":"10.1016/j.mechmat.2025.105293","url":null,"abstract":"<div><div>The dynamic effective properties of piezoelectric composites containing inclusions oriented in arbitrary directions are studied using the self-consistent method. The direction angle distribution function is introduced to describe the orientations of inclusions. An interpolation method for calculating the angle average integral is provided. The results of this work show good agreement with other theoretical and experimental results, both for the static and dynamic effective properties. The effect of the volume fraction on the effective phase velocity and attenuation is examined. The influence of the degree of alignment of the inclusions on the effective elastic moduli and resonant frequency is analyzed. The results show that the effects of the shape and orientation of the inclusions, as well as the frequency, act jointly rather than independently. The model will offer theoretical insights into controlling elastic waves in piezoelectric composites by adjusting the orientation of inclusions.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"204 ","pages":"Article 105293"},"PeriodicalIF":3.4,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.mechmat.2025.105275
Tim Furlan , Markus Schewe , Philipp Scherm , Philipp Retzl , Ernst Kozeschnik , Andreas Menzel
Control of the microstructure of steel components during their processing is a crucial factor for reaching desired product properties. Realistic simulations of the microstructure evolution during processing can facilitate the improvement of existing processes as well as the design of new ones by reducing the need for time- and cost-intensive experimental investigations. This work focuses on the modelling and advanced simulation of quenching of components made of the high-carbon bearing steels 100Cr6 and 100CrMnSi6-4, during which transformations from austenite to martensite and bainite are considered. Special attention is given to the carbon-enrichment of the austenite phase during the formation of carbide-free bainite, since the change in carbon content also changes the martensite start temperature. A novel model based on the widely used Koistinen–Marburger and Johnson–Mehl–Avrami–Kolmogorov models is proposed, which explicitly takes into account the carbon contents of the remaining austenite and its influence on the kinetics of both transformations. The proposed model is implemented as a user material for the commercial finite element software Abaqus. Our source code and calibration data are available at https://github.com/InstituteOfMechanics/Phase_Trafos_Carbon_Repartitioning.
{"title":"Modelling and finite element simulation of martensite and bainite phase transformations during quenching under consideration of carbon repartitioning","authors":"Tim Furlan , Markus Schewe , Philipp Scherm , Philipp Retzl , Ernst Kozeschnik , Andreas Menzel","doi":"10.1016/j.mechmat.2025.105275","DOIUrl":"10.1016/j.mechmat.2025.105275","url":null,"abstract":"<div><div>Control of the microstructure of steel components during their processing is a crucial factor for reaching desired product properties. Realistic simulations of the microstructure evolution during processing can facilitate the improvement of existing processes as well as the design of new ones by reducing the need for time- and cost-intensive experimental investigations. This work focuses on the modelling and advanced simulation of quenching of components made of the high-carbon bearing steels 100Cr6 and 100CrMnSi6-4, during which transformations from austenite to martensite and bainite are considered. Special attention is given to the carbon-enrichment of the austenite phase during the formation of carbide-free bainite, since the change in carbon content also changes the martensite start temperature. A novel model based on the widely used Koistinen–Marburger and Johnson–Mehl–Avrami–Kolmogorov models is proposed, which explicitly takes into account the carbon contents of the remaining austenite and its influence on the kinetics of both transformations. The proposed model is implemented as a user material for the commercial finite element software Abaqus. Our source code and calibration data are available at <span><span>https://github.com/InstituteOfMechanics/Phase_Trafos_Carbon_Repartitioning</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"204 ","pages":"Article 105275"},"PeriodicalIF":3.4,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is devoted to the study of Ti6Al4V ELI (Extra Low Interstitials) processed by electron beam melting (EBM). The experimental investigation includes quasi-static uniaxial tension and compression tests and free-end torsion tests. It was found that the horizontally and vertically printed specimens have the same yield stresses and similar overall stress-strain response. Irrespective of the printing direction the material displays strength differential effects. During monotonic compression tests, a slight anisotropy in plastic strains in compression was revealed by online optical measurements. This slight anisotropy was confirmed by conducting interrupted compression tests and further measuring the deformed cross-sections. Although the material anisotropy is weak, the torsional response cannot be captured with the von Mises yield function. On the other hand, using the isotropic Cazacu and Barlat (2004) yield function that involves only one additional parameter that can be determined solely from uniaxial tension and compression tests, both strength differential effects and the material's torsional response are predicted with accuracy. Furthermore, a transversely isotropic extension of this yield criterion involving only two additional anisotropy coefficients that can be determined using analytical formulas from uniaxial data, enables to account for both the mild anisotropy and the material's tension compression asymmetry and to obtain good predictions for all test conditions investigated.
{"title":"Plastic behavior of additively manufactured Ti6Al4V ELI: Mechanical characterization, engineering scale modeling, and validation using free-end torsion tests","authors":"Luca Corallo , Oana Cazacu , Raffaele Barbagallo , Giuseppe Mirone","doi":"10.1016/j.mechmat.2025.105291","DOIUrl":"10.1016/j.mechmat.2025.105291","url":null,"abstract":"<div><div>This paper is devoted to the study of Ti6Al4V ELI (Extra Low Interstitials) processed by electron beam melting (EBM). The experimental investigation includes quasi-static uniaxial tension and compression tests and free-end torsion tests. It was found that the horizontally and vertically printed specimens have the same yield stresses and similar overall stress-strain response. Irrespective of the printing direction the material displays strength differential effects. During monotonic compression tests, a slight anisotropy in plastic strains in compression was revealed by online optical measurements. This slight anisotropy was confirmed by conducting interrupted compression tests and further measuring the deformed cross-sections. Although the material anisotropy is weak, the torsional response cannot be captured with the von Mises yield function. On the other hand, using the isotropic Cazacu and Barlat (2004) yield function that involves only one additional parameter that can be determined solely from uniaxial tension and compression tests, both strength differential effects and the material's torsional response are predicted with accuracy. Furthermore, a transversely isotropic extension of this yield criterion involving only two additional anisotropy coefficients that can be determined using analytical formulas from uniaxial data, enables to account for both the mild anisotropy and the material's tension compression asymmetry and to obtain good predictions for all test conditions investigated.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"203 ","pages":"Article 105291"},"PeriodicalIF":3.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-07DOI: 10.1016/j.mechmat.2025.105270
Hossein Naderi, Roozbeh Dargazany
The influence of oxidation on the degradation of polymers is one of the most critical aging processes. The oxidation is usually limited to the sample’s surface, commonly called diffusion-limited oxidation (DLO). DLO occurs through the competition of simultaneous oxygen absorption, diffusion transport, and the reaction of oxygen in the elastomers. A new kinetics-based oxygen absorption model is developed and validated against multiple experimental data. In addition, the diffusion-reaction equation is extended in 3 dimensions and solved by the Alternating Direction Implicit (ADI) method. Various reaction rate functions are considered for chain scission and network reformation reactions to describe non-uniform degradation. An enhanced model is utilized to simulate the heterogeneous oxidation and to demonstrate the influence of contributing factors on the oxidation behavior of nitrite rubber. Our proposed model’s results agree with the empirical data on polymers’ oxidation degree. In addition, a constitutive model is developed that incorporates the coupling between diffusion, chemical reaction, and large deformation of polymers. The finite element implementation of the coupled multi-physics is explained in detail. The proposed constitutive model illustrates the effect of diffusion-limited oxidation (DLO) on the mechanical properties of cross-linked polymers. It numerically analyzes the coupled diffusion–reaction and mechanical behavior of polymers undergoing DLO.
{"title":"Constitutive modeling of diffusion-limited oxidation coupled with a large deformation theory for polymer degradation","authors":"Hossein Naderi, Roozbeh Dargazany","doi":"10.1016/j.mechmat.2025.105270","DOIUrl":"10.1016/j.mechmat.2025.105270","url":null,"abstract":"<div><div>The influence of oxidation on the degradation of polymers is one of the most critical aging processes. The oxidation is usually limited to the sample’s surface, commonly called diffusion-limited oxidation (DLO). DLO occurs through the competition of simultaneous oxygen absorption, diffusion transport, and the reaction of oxygen in the elastomers. A new kinetics-based oxygen absorption model is developed and validated against multiple experimental data. In addition, the diffusion-reaction equation is extended in 3 dimensions and solved by the Alternating Direction Implicit (ADI) method. Various reaction rate functions are considered for chain scission and network reformation reactions to describe non-uniform degradation. An enhanced model is utilized to simulate the heterogeneous oxidation and to demonstrate the influence of contributing factors on the oxidation behavior of nitrite rubber. Our proposed model’s results agree with the empirical data on polymers’ oxidation degree. In addition, a constitutive model is developed that incorporates the coupling between diffusion, chemical reaction, and large deformation of polymers. The finite element implementation of the coupled multi-physics is explained in detail. The proposed constitutive model illustrates the effect of diffusion-limited oxidation (DLO) on the mechanical properties of cross-linked polymers. It numerically analyzes the coupled diffusion–reaction and mechanical behavior of polymers undergoing DLO.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"203 ","pages":"Article 105270"},"PeriodicalIF":3.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-06DOI: 10.1016/j.mechmat.2025.105274
Alireza Edalatmanesh, Maryam Mahnama
Nanoglasses (NGs) as a novel type of amorphous material with tunable microstructure have paved the way for engineering the structure of amorphous materials with tailored performance. Central to this effort is modifying microstructural features (through altering processing routes), which is made possible by a comprehensive understanding of process-structure-properties relationships. Research on NGs has frequently limited its scope to specific processing parameters or focused solely on identifying trends. This study provides a comprehensive investigation of the process-structure-mechanical property relationships in Cu-Zr NGs by employing molecular dynamics simulations. It focuses on how main process parameters like temperature, glass quenching rate, core grain size, and composition affect NGs' structural characteristics and mechanical behavior. The findings indicate that process parameters such as temperature, glass quenching rate, and composition substantially affect atomic volume profiles and the formation of Voronoi clusters. Conversely, grain size specifically influences the volume fractions of the constituent phases. Analysis of NGs’ mechanical responses under diverse processing parameters reveals that generally, any process parameters that induce excess free volume along with loosely-packed clusters result in lower ultimate strength and a softer elastic response. Additionally, the post-ultimate tensile strength behavior and degree of homogeneous plasticity in NGs are primarily influenced by the grain size. Moreover, investigation of deformation mechanisms reveals three phases: the nucleation of shear-activated atoms, the activation of shear transformation zones, and the shear localization. The findings lay the groundwork for the material design of NGs with enhanced mechanical performance through controlling processing conditions, offering practical applications in harsh environments.
{"title":"Process-structure-mechanical property relationships in Cu-Zr nanoglass: Insights from molecular dynamics","authors":"Alireza Edalatmanesh, Maryam Mahnama","doi":"10.1016/j.mechmat.2025.105274","DOIUrl":"10.1016/j.mechmat.2025.105274","url":null,"abstract":"<div><div>Nanoglasses (NGs) as a novel type of amorphous material with tunable microstructure have paved the way for engineering the structure of amorphous materials with tailored performance. Central to this effort is modifying microstructural features (through altering processing routes), which is made possible by a comprehensive understanding of process-structure-properties relationships. Research on NGs has frequently limited its scope to specific processing parameters or focused solely on identifying trends. This study provides a comprehensive investigation of the process-structure-mechanical property relationships in Cu-Zr NGs by employing molecular dynamics simulations. It focuses on how main process parameters like temperature, glass quenching rate, core grain size, and composition affect NGs' structural characteristics and mechanical behavior. The findings indicate that process parameters such as temperature, glass quenching rate, and composition substantially affect atomic volume profiles and the formation of Voronoi clusters. Conversely, grain size specifically influences the volume fractions of the constituent phases. Analysis of NGs’ mechanical responses under diverse processing parameters reveals that generally, any process parameters that induce excess free volume along with loosely-packed clusters result in lower ultimate strength and a softer elastic response. Additionally, the post-ultimate tensile strength behavior and degree of homogeneous plasticity in NGs are primarily influenced by the grain size. Moreover, investigation of deformation mechanisms reveals three phases: the nucleation of shear-activated atoms, the activation of shear transformation zones, and the shear localization. The findings lay the groundwork for the material design of NGs with enhanced mechanical performance through controlling processing conditions, offering practical applications in harsh environments.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"203 ","pages":"Article 105274"},"PeriodicalIF":3.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-04DOI: 10.1016/j.mechmat.2025.105276
Weilin Shi , Yuheng Liu , Haibao Lu , Yong-Qing Fu
Study on length-change effect in macromolecular chains is of critical importance for understanding mechanical behaviors of soft hydrogels, but mechanisms of force-induced transitions in macromolecular chains in soft hydrogels have not been fully understood due to their complex thermodynamics and kinetics. Herein, a globule-coil transition model is proposed to describe the force-induced length-change effect in macromolecular chains, of which the rubber elasticity and stiffening principles in hydrogels are investigated. A molecular model is firstly formulated to capture the microscopic physical mechanisms of the length-change effect based on the renormalized blob theory, and a free-energy equation is then proposed to characterize the globule-coil transition of macromolecular chains and rubber elasticity of polymer networks, based on the Flory-Huggins theory, entropic elasticity model, tube model and linear spring model. A kinetic equation for the force-induced globule-coil transition in macromolecular chains is further developed to describe the length-change effect, solved by finite difference method (FDM). Finally, quantitative comparisons have been conducted and good agreements have been achieved between the analytical results of proposed model and experimental data reported in literature. Our study provides a new perspective towards fully understanding of the length-change effect in macromolecular chains, rubbery elasticity, and stiffening principles in soft hydrogels undergoing mechanochemical coupling.
{"title":"Force-induced length-change effect of macromolecular chains undergoing mechanochemical coupling and mechanical behaviors under uniaxial tension in soft hydrogels","authors":"Weilin Shi , Yuheng Liu , Haibao Lu , Yong-Qing Fu","doi":"10.1016/j.mechmat.2025.105276","DOIUrl":"10.1016/j.mechmat.2025.105276","url":null,"abstract":"<div><div>Study on length-change effect in macromolecular chains is of critical importance for understanding mechanical behaviors of soft hydrogels, but mechanisms of force-induced transitions in macromolecular chains in soft hydrogels have not been fully understood due to their complex thermodynamics and kinetics. Herein, a globule-coil transition model is proposed to describe the force-induced length-change effect in macromolecular chains, of which the rubber elasticity and stiffening principles in hydrogels are investigated. A molecular model is firstly formulated to capture the microscopic physical mechanisms of the length-change effect based on the renormalized blob theory, and a free-energy equation is then proposed to characterize the globule-coil transition of macromolecular chains and rubber elasticity of polymer networks, based on the Flory-Huggins theory, entropic elasticity model, tube model and linear spring model. A kinetic equation for the force-induced globule-coil transition in macromolecular chains is further developed to describe the length-change effect, solved by finite difference method (FDM). Finally, quantitative comparisons have been conducted and good agreements have been achieved between the analytical results of proposed model and experimental data reported in literature. Our study provides a new perspective towards fully understanding of the length-change effect in macromolecular chains, rubbery elasticity, and stiffening principles in soft hydrogels undergoing mechanochemical coupling.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"203 ","pages":"Article 105276"},"PeriodicalIF":3.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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