Physics-informed neural networks(PINNs)have emerged as a promising class of scientific machine learning techniques that integrate governing physical laws into neural network training.Their ability to enforce different...Physics-informed neural networks(PINNs)have emerged as a promising class of scientific machine learning techniques that integrate governing physical laws into neural network training.Their ability to enforce differential equations,constitutive relations,and boundary conditions within the loss function provides a physically grounded alternative to traditional data-driven models,particularly for solid and structural mechanics,where data are often limited or noisy.This review offers a comprehensive assessment of recent developments in PINNs,combining bibliometric analysis,theoretical foundations,application-oriented insights,and methodological innovations.A biblio-metric survey indicates a rapid increase in publications on PINNs since 2018,with prominent research clusters focused on numerical methods,structural analysis,and forecasting.Building upon this trend,the review consolidates advance-ments across five principal application domains,including forward structural analysis,inverse modeling and parameter identification,structural and topology optimization,assessment of structural integrity,and manufacturing processes.These applications are propelled by substantial methodological advancements,encompassing rigorous enforcement of boundary conditions,modified loss functions,adaptive training,domain decomposition strategies,multi-fidelity and transfer learning approaches,as well as hybrid finite element–PINN integration.These advances address recurring challenges in solid mechanics,such as high-order governing equations,material heterogeneity,complex geometries,localized phenomena,and limited experimental data.Despite remaining challenges in computational cost,scalability,and experimental validation,PINNs are increasingly evolving into specialized,physics-aware tools for practical solid and structural mechanics applications.展开更多
Cells interact with the extracellular matrix and generate traction forces,which play fundamental roles in many cytological activities,such as migration and differentiation.The quanti fication of these traction forces ...Cells interact with the extracellular matrix and generate traction forces,which play fundamental roles in many cytological activities,such as migration and differentiation.The quanti fication of these traction forces is a prerequisite for understanding the interaction and regulation between force and functions,which can be accomplished by traction force microscopy(TFM).In TFM,the forces are determined by tracking the displacement of fiducial markers through optical microscopy.The type of fiducial marker,microscopy modality,and image processing algorithms are key factors determining the final resolution of TFM.This review summarizes efforts in three aspects to enhance the performance of TFM and discusses the challenges of further development,particularly from an optical view.展开更多
The airflow mechanics in adult nasal airways,whether healthy or abnormal,are extensively studied and investigated,but the flow mechanics in child nasal airways remain underexplored.This study investigates the airflow ...The airflow mechanics in adult nasal airways,whether healthy or abnormal,are extensively studied and investigated,but the flow mechanics in child nasal airways remain underexplored.This study investigates the airflow mechanics in the child’s nasal upper airway with adenoid hypertrophy,with an adenoid nasopharyngeal ratio(AN of 0.9),under cyclic inhalation and exhalation.An inlet respiratory cycle with three different flow rates(3.2 L/min calm breathing,8.6 L/min normal breathing,and 19.3 L/min intensive breathing)was simulated by using the computational fluid dynamics approach.To better capture the interaction between airflow and the flexible airway tissue,fluid-structure interaction analysis was performed at the normal breathing rate.Comparing the airflow dynamics during inhalation and exhalation,the pressure drops,nasal resistance,and wall shear stress show significant differences in the nasopharyngeal region for all different flow rates.This observation suggests that the inertial effect associated with the transient flow is important during exhalation and inhalation.Furthermore,the considerable temporal variation in flow rate distribution across a specific cross-section of the nasal airway highlights the critical role of transient data in virtual surgery planning and data for clinical decisions.展开更多
UHMWPE fibers exhibit impressive modulus and strength,but they have not reached their theoretical limits.Researchers focus on molecular weight,orientation,and crystallinity of UHMWPE,yet their contributions to mechani...UHMWPE fibers exhibit impressive modulus and strength,but they have not reached their theoretical limits.Researchers focus on molecular weight,orientation,and crystallinity of UHMWPE,yet their contributions to mechanical properties are unclear.Molecular dynamics simulations are valuable but often limited by computational constraints.Our aim is to simulate higher molecular weights to better represent real UHMWPE fibers.We used Packmol and Polyply methodologies to construct PE systems,with Polyply reproducing more reasonable properties of UHMWPE fibers.Additionally,tensile simulations showed that orientation and crystallinity greatly impact Young's modulus more than molecular weight.Energy decomposition indicated that higher molecular weights lead to covalent bonds that can withstand more energy during stretching,thus increasing breaking strength.Combining simulations with machine learning,we found that orientation has the most significant impact on Young's modulus,contributing 60%,and molecular weight plays the most crucial role in determining the breaking strength,accounting for 65%.This study provides a theoretical basis and guidelines for enhancing UHMWPE's modulus and strength.展开更多
Accurate mechanical modeling is essential for robotic belt grinding(RBG), a process characterized by compliant contact mechanisms that make force prediction particularly challenging. However, existing mechanical model...Accurate mechanical modeling is essential for robotic belt grinding(RBG), a process characterized by compliant contact mechanisms that make force prediction particularly challenging. However, existing mechanical models predominantly focus on macroscale compliance while neglecting grain-scale compliant motion. Moreover, abrasive grains are typically idealized as regular shapes, overlooking the inherent stochasticity of real grain geometries. This study proposes a shapeequivalence method for modeling stochastic abrasive grains and develops a multiscale compliant force model for RBG. Specifically, an individual grain is represented as a polygonal pyramid with stochastic edges that is mathematically equivalent to a cone;this method unifies the treatment of grain geometries and streamlines the modeling process. The mathematical equivalence relationship for random grain shapes is further derived based on a grain-compliant contact model. By integrating grain geometric characteristics and progressive grain wear, an analytical mechanical model that captures both the static contact force and dynamic grinding force is established, thereby describing the transition from grain-workpiece compliant interaction to belt-workpiece elastic contact. Grinding experiments were conducted using abrasive belts with different grain shape distributions to validate the model. The results demonstrated reliable predictions of the tangential grinding force and its component characteristics. Additional analyses were performed to reveal how the tangential grinding force varies with wear time and grinding parameters.展开更多
Understanding the mechanical behavior of diagenetic mineral granules and interfaces in granite provides essential experimental references for constructing micromechanical models of granite.The micromechanical behavior...Understanding the mechanical behavior of diagenetic mineral granules and interfaces in granite provides essential experimental references for constructing micromechanical models of granite.The micromechanical behavior of Yanshanian granite is investigated using scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS)and nanoindentation tests.The results demonstrate transitional mechanical properties at mineral interfaces.The elastic modulus and hardness exhibit intermediate values between adjacent mineral phases.The higher plasticity indices at the interfaces suggest higher plastic deformation capacity of hard-phase minerals in these regions.Additionally,fracture toughness measurements of minerals and interfaces were obtained,with interfacial values ranging from 0.90 to 1.63 MPa·m^(0.5).The analysis of mechanical property relationships shows a significant positive linear correlation between rock-scale elastic modulus and fracture toughness.However,this correlation is substantially lower at the mineral scale,demonstrating a scale effect in the relationship of different mechanical properties.展开更多
On May 9,2025 on the campus of the University of Science and Technology of China(USTC),Chinese Academy of Sciences(CAS),an exhibition was unveiled to celebrate the UN International Year of Quantum Science and Technolo...On May 9,2025 on the campus of the University of Science and Technology of China(USTC),Chinese Academy of Sciences(CAS),an exhibition was unveiled to celebrate the UN International Year of Quantum Science and Technology(IYQ)-a one-year-long worldwide event in memory of the founding of quantum mechanics(QM).展开更多
The integration of physics-based modelling and data-driven artificial intelligence(AI)has emerged as a transformative paradigm in computational mechanics.This perspective reviews the development and current status of ...The integration of physics-based modelling and data-driven artificial intelligence(AI)has emerged as a transformative paradigm in computational mechanics.This perspective reviews the development and current status of AI-empowered frameworks,including data-driven methods,physics-informed neural networks,and neural operators.While these approaches have demonstrated significant promise,challenges remain in terms of robustness,generalisation,and computational efficiency.We delineate four promising research directions:(1)Modular neural architectures inspired by traditional computational mechanics,(2)physics informed neural operators for resolution-invariant operator learning,(3)intelligent frameworks for multiphysics and multiscale biomechanics problems,and(4)structural optimisation strategies based on physics constraints and reinforcement learning.These directions represent a shift toward foundational frameworks that combine the strengths of physics and data,opening new avenues for the modelling,simulation,and optimisation of complex physical systems.展开更多
In recent years,large language models(LLMs)have demonstrated immense potential in practical applications to enhance work efficiency and decision-making capabilities.However,specialized LLMs in the oil and gas engineer...In recent years,large language models(LLMs)have demonstrated immense potential in practical applications to enhance work efficiency and decision-making capabilities.However,specialized LLMs in the oil and gas engineering area are rarely developed.To aid in exploring and developing deep and ultra-deep unconventional reservoirs,there is a call for a personalized LLM on oil-and gas-related rock mechanics,which may handle complex professional data and make intelligent predictions and decisions.To that end,herein,we overview general and industry-specific LLMs.Then,a systematic workflow is proposed for building this domain-specific LLM for oil and gas engineering,including data collection and processing,model construction and training,model validation,and implementation in the specific domain.Moreover,three application scenarios are investigated:knowledge extraction from textural resources,field operation with multidisciplinary integration,and intelligent decision assistance.Finally,several challenges in developing this domain-specific LLM are highlighted.Our key findings are that geological surveys,laboratory experiments,field tests,and numerical simulations form the four original sources of rock mechanics data.Those data must flow through collection,storage,processing,and governance before being fed into LLM training.This domain-specific LLM can be trained by fine-tuning a general open-source LLM with professional data and constraints such as rock mechanics datasets and principles.The LLM can then follow the commonly used training and validation processes before being implemented in the oil and gas field.However,there are three primary challenges in building this domain-specific LLM:data standardization,data security and access,and striking a compromise between physics and data when building the model structure.Some of these challenges are administrative rather than technical,and overcoming those requires close collaboration between the different interested parties and various professional practitioners.展开更多
The low-temperature embrittlement limits the service temperature of ferritic and duplex stainless steels.The effects of alloying elements added to Fe-Cr binary system on the low-temperature embrittlement have been rev...The low-temperature embrittlement limits the service temperature of ferritic and duplex stainless steels.The effects of alloying elements added to Fe-Cr binary system on the low-temperature embrittlement have been reviewed critically.Prior literature on the underlying phase transformation,i.e.,phase separation(PS)and changes of mechanical properties,is surveyed.The available literature indicates that the rate of PS is accelerated by Ni or Co in Fe-Cr binary system.The increased kinetics of PS also lead to an enhanced hardening rate during aging for Ni and Co alloyed Fe-Cr alloys.In low Cr(<17 wt.%)ferritic alloys,the additions of Al or Co can reduce embrittlement because these elements contribute to lowering the driving force for PS.The influence of other alloying elements such as Mo,Cu,Mn,Nb,and Ti is inconclusive but also discussed here.Thermodynamic and kinetic calculations were performed to evaluate current CALPHAD databases and to further investigate the thermodynamic and kinetic reasons for the effect of the additional alloying elements added to Fe-Cr alloy on PS.Some indications were provided for improving physically-based predictions of low-temperature embrittlement as well as opportunities to mitigate the phenomenon by alloying.展开更多
Conventional geostress evaluation methods often assume static rock properties and neglect the dynamic degradation of mechanical parameters caused by damage evolution during drilling and fracturing processes,which sign...Conventional geostress evaluation methods often assume static rock properties and neglect the dynamic degradation of mechanical parameters caused by damage evolution during drilling and fracturing processes,which significantly limits prediction accuracy.To address this gap,this study develops a multiphysics-coupled numerical framework integrating COMSOL Multiphysics and MATLAB,grounded in damage mechanics theory,to quantitatively investigate the control mechanism of progressive rock damage on geostress redistribution.By establishing a damage constitutive model coupled with thermo-hydro-mechanical interactions,we simulate the dynamic evolution of rock damage and its impact on stress field reorganization during wellbore operations.Key results demonstrate that(1)incorporating damage evolution leads to substantial deviations in both the magnitude and spatial distribution of geostress,with stress perturbations highly localized within damage zones;(2)changes in mechanical parameters-particularly elastic modulus and permeability-dominate stress adjustments,with heightened sensitivity in formations with low elastic moduli and high permeability;and(3)Poisson's ratio has a negligible influence,whereas permeability variation becomes critically important in low-stiffness formations.Field validation via leakage case analyses in the Wujiaping Formation confirms that the proposed method significantly enhances prediction accuracy compared with conventional approaches.This work elucidates the multiscale interdependency between damage and stress evolution by offering a physics-based framework to optimize drilling and stimulation design in heterogeneous reservoirs.展开更多
We are pleased to introduce this special thematic section on Nanofluid Mechanics and Heat Transfer that is being included in Acta Mechanica Sinica(AMS).This thematic issue consists of 6 papers selected from papers tha...We are pleased to introduce this special thematic section on Nanofluid Mechanics and Heat Transfer that is being included in Acta Mechanica Sinica(AMS).This thematic issue consists of 6 papers selected from papers that were presented at the 18th International Symposium on Numer-ical Analysis of Fluid Flows,Heat and Mass Transfer-Nu-merical Fluids 2023,held in Heraklion,Crete Greece,11-17 September 2023,and invited through a general call.The symposium covers various subjects:from new numerical methods and fundamental research until engineering appli-cations,and it is a part of the International Conference of Numerical Analysis and Applied Mathematics(ICNAAM),held annually.展开更多
Multi⁃field coupling problems involving species transport,heat transfer,substance transformation,and mechanical deformation are prevalent in various scenarios,such as the curing of early⁃age concretes,the response of ...Multi⁃field coupling problems involving species transport,heat transfer,substance transformation,and mechanical deformation are prevalent in various scenarios,such as the curing of early⁃age concretes,the response of soft materials,the oxidation of metals,the lithiation and delithiation of lithium⁃ion batteries,and the self⁃healing of biological tissues.Thermo⁃chemo⁃mechanical coupling dynamics are common characteristics of these problems,making theoretical studies on such processes of significant importance.This study offers a thorough review of advanced theoretical models that address thermo⁃chemo⁃mechanical behavior of solid materials within the theoretical framework of non⁃equilibrium thermodynamics.First,we outline the thermo⁃chemo⁃mechanical coupling phenomena observed in various application scenarios.Then,the theoretical developments of classical continuum mechanics include the phase field method and peridynamics in the contexts of thermo⁃mechanical coupling,chemo⁃mechanical coupling,and thermo⁃chemo⁃mechanical coupling,respectively.Finally,challenges faced by thermo⁃chemo⁃mechanical coupling research are highlighted and prospects and directions for this field are also outlined.This paper helps to understand the history and trends in the development of thermo⁃chemo⁃mechanical coupling theory.展开更多
The mechanical properties of biological soft tissues play a critical role in the study of biomechanics and the development of protective measures against human injury.Various testing techniques at different scales hav...The mechanical properties of biological soft tissues play a critical role in the study of biomechanics and the development of protective measures against human injury.Various testing techniques at different scales have been employed to characterize the mechanical behavior of soft tissues,which is essential for developing accurate tissue simulants and numerical models.This review comprehensively explores the mechanical properties of soft tissues,examining experimental methods,mechanical models,numerical simulations,and the progress in materials that mimic the mechanical performance of soft tissues.Finally,it reviews the damage and protection of human tissues under kinetic impacts,anticipating the future construction of soft tissue surrogate targets.The aim is to provide a systematic theoretical foundation and the latest advancements in the field,addressing the design,preparation,and quantitative modeling of biomimetic materials,thereby promoting the in-depth development of soft tissue mechanics and its applications.展开更多
Graphene,a two-dimensional material with atomic thickness,holds significant importance in advancing the existing theories of solid mechanics.However,as an intersection of multiple scales,it poses challenges to experim...Graphene,a two-dimensional material with atomic thickness,holds significant importance in advancing the existing theories of solid mechanics.However,as an intersection of multiple scales,it poses challenges to experimental measurements of its mechanical behaviors.This review comprehensively discusses the recent achievements in experimental studies on the mechanics of graphene,focusing on sample preparation,loading design,and measurement techniques.Moreover,personal perspectives on the future development in this field are presented,aiming to provide insights and inspiration for researchers engaged in related studies.展开更多
This paper presents a novel element differential method for modeling cracks in piezoelectric materials,aiming to simulate fracture behaviors and predict the fracture parameter known as the J-integral accurately.The me...This paper presents a novel element differential method for modeling cracks in piezoelectric materials,aiming to simulate fracture behaviors and predict the fracture parameter known as the J-integral accurately.The method leverages an efficient collocation technique to satisfy traction and electric charge equilibrium on the crack surface,aligning internal nodes with piezoelectric governing equations without needing integration or variational principles.It combines the strengths of the strong form collocation and finite element methods.The J-integral is derived analytically using the equivalent domain integral method,employing Green's formula and Gauss's divergence theorem to transform line integrals into area integrals for solving two-dimensional piezoelectric material problems.The accuracy of the method is validated through comparison with three typical examples,and it offers fracture prevention strategies for engineering piezoelectric structures under different electrical loading patterns.展开更多
In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle...In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle Fatigue(MLCF)life of perforated structures.First,fatigue tests are carried out on three center-perforated structures,aiming to assess their fatigue life under various strengthening conditions.These tests reveal significant variations in fatigue life,accompanied by an examination of crack initiation through the analysis of fatigue fracture surfaces.Second,an innovative fatigue life prediction methodology is applied to perforated structures,which not only forecasts the initiation of fatigue cracks but also traces the progression of damage within these structures.It leverages an elastoplastic constitutive model integrated with damage and a damage evolution model under cyclic loads.The accuracy of this approach is validated by comparison with test results,falling within the three times error band.Finally,we explore the impact of various strengthening techniques,including cross-sectional reinforcement and cold expansion,on the fatigue life and damage evolution of these structures.This is achieved through an in-depth comparative analysis of both experimental data and computational predictions,which provides valuable insights into the behavior of perforated structures under fatigue conditions in practical applications.展开更多
As a core course for the Engineering Cost major at Chongqing Institute of Engineering,Engineering Mechanics shoulders the dual mission of cultivating students’mechanical thinking,engineering practical abilities,and p...As a core course for the Engineering Cost major at Chongqing Institute of Engineering,Engineering Mechanics shoulders the dual mission of cultivating students’mechanical thinking,engineering practical abilities,and professional qualities.Centered on the deep integration of the outcome-based education(OBE)concept and curriculum-based ideological and political education,this paper systematically elaborates on the reform paths and implementation strategies from four dimensions-reconstruction of teaching content,innovation of assessment mechanisms,integration of ideological and political elements,and construction of teaching resources-by drawing on the teaching reform practices of Engineering Mechanics courses at multiple universities.Through modular teaching content design,a competency-oriented diversified assessment system,and a method of integrating ideological and political education with local characteristics and engineering case studies,the teaching objectives of“knowledge transmission,ability cultivation,and value shaping”are achieved in a three-in-one manner.Practical results indicate that after the reform,students’engineering practical abilities have significantly improved,with a course objective achievement rate exceeding 0.73,a 23%increase in student satisfaction with the course,and a 35%year-on-year increase in the number of awards won in professional competitions,providing a replicable paradigm for the teaching reform of engineering courses.展开更多
Considering the three typical phase-change related rock mechanics phenomena during drilling and production in oil and gas reservoirs,which include phase change of solid alkane-related mixtures upon heating,sand liquef...Considering the three typical phase-change related rock mechanics phenomena during drilling and production in oil and gas reservoirs,which include phase change of solid alkane-related mixtures upon heating,sand liquefaction induced by sudden pressure release of the over-pressured sand body,and formation collapse due to gasification of pore fillings from pressure reduction,this study first systematically analyzes the progress of theoretical understanding,experimental methods,and mathematical representation,then discusses the engineering application scenarios corresponding to the three phenomena and reveals the mechanical principles and application effectiveness.Based on these research efforts,the study further discusses the significant challenges,potential developmental trends,and research approaches that require urgent exploration.The findings disclose that various phase-related rock mechanics phenomena require specific experimental and mathematical methods that can produce multi-field coupling mechanical mechanisms,which will eventually instruct the control on resource exploitation,evaluation on disaster level,and analysis of formation stability.To meet the development needs of the principle,future research efforts should focus on mining more phase-change related rock mechanics phenomena during oil and gas resources exploitation,developing novel experimental equipment,and using techniques of artificial intelligence and digital twins to implement real-time simulation and dynamic visualization of phase-change related rock mechanics.展开更多
Significant advances in battery and fuel cell technologies over the past decade have catalyzed the transition toward electrified transportation systems and large-scale renewable energy integration.Concurrent with thes...Significant advances in battery and fuel cell technologies over the past decade have catalyzed the transition toward electrified transportation systems and large-scale renewable energy integration.Concurrent with these developments,the interdisciplinary role of mechanics has emerged as a critical research frontier.展开更多
基金funded by National Research Council of Thailand(contract No.N42A671047).
文摘Physics-informed neural networks(PINNs)have emerged as a promising class of scientific machine learning techniques that integrate governing physical laws into neural network training.Their ability to enforce differential equations,constitutive relations,and boundary conditions within the loss function provides a physically grounded alternative to traditional data-driven models,particularly for solid and structural mechanics,where data are often limited or noisy.This review offers a comprehensive assessment of recent developments in PINNs,combining bibliometric analysis,theoretical foundations,application-oriented insights,and methodological innovations.A biblio-metric survey indicates a rapid increase in publications on PINNs since 2018,with prominent research clusters focused on numerical methods,structural analysis,and forecasting.Building upon this trend,the review consolidates advance-ments across five principal application domains,including forward structural analysis,inverse modeling and parameter identification,structural and topology optimization,assessment of structural integrity,and manufacturing processes.These applications are propelled by substantial methodological advancements,encompassing rigorous enforcement of boundary conditions,modified loss functions,adaptive training,domain decomposition strategies,multi-fidelity and transfer learning approaches,as well as hybrid finite element–PINN integration.These advances address recurring challenges in solid mechanics,such as high-order governing equations,material heterogeneity,complex geometries,localized phenomena,and limited experimental data.Despite remaining challenges in computational cost,scalability,and experimental validation,PINNs are increasingly evolving into specialized,physics-aware tools for practical solid and structural mechanics applications.
基金supported by the Major Research Instrument Development Project of the National Natural Science Foundation of China(32527801)the National Natural Science Foundation of China(32301168)+1 种基金the Ningbo Natural Science Foundation of China(2023J351)the Yongjiang Innovative Talents Project of Ningbo City(2024A-172-G).
文摘Cells interact with the extracellular matrix and generate traction forces,which play fundamental roles in many cytological activities,such as migration and differentiation.The quanti fication of these traction forces is a prerequisite for understanding the interaction and regulation between force and functions,which can be accomplished by traction force microscopy(TFM).In TFM,the forces are determined by tracking the displacement of fiducial markers through optical microscopy.The type of fiducial marker,microscopy modality,and image processing algorithms are key factors determining the final resolution of TFM.This review summarizes efforts in three aspects to enhance the performance of TFM and discusses the challenges of further development,particularly from an optical view.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0707601).
文摘The airflow mechanics in adult nasal airways,whether healthy or abnormal,are extensively studied and investigated,but the flow mechanics in child nasal airways remain underexplored.This study investigates the airflow mechanics in the child’s nasal upper airway with adenoid hypertrophy,with an adenoid nasopharyngeal ratio(AN of 0.9),under cyclic inhalation and exhalation.An inlet respiratory cycle with three different flow rates(3.2 L/min calm breathing,8.6 L/min normal breathing,and 19.3 L/min intensive breathing)was simulated by using the computational fluid dynamics approach.To better capture the interaction between airflow and the flexible airway tissue,fluid-structure interaction analysis was performed at the normal breathing rate.Comparing the airflow dynamics during inhalation and exhalation,the pressure drops,nasal resistance,and wall shear stress show significant differences in the nasopharyngeal region for all different flow rates.This observation suggests that the inertial effect associated with the transient flow is important during exhalation and inhalation.Furthermore,the considerable temporal variation in flow rate distribution across a specific cross-section of the nasal airway highlights the critical role of transient data in virtual surgery planning and data for clinical decisions.
基金financially supported by the National Natural Science Foundation of China(Nos.52303298 and 52233002)。
文摘UHMWPE fibers exhibit impressive modulus and strength,but they have not reached their theoretical limits.Researchers focus on molecular weight,orientation,and crystallinity of UHMWPE,yet their contributions to mechanical properties are unclear.Molecular dynamics simulations are valuable but often limited by computational constraints.Our aim is to simulate higher molecular weights to better represent real UHMWPE fibers.We used Packmol and Polyply methodologies to construct PE systems,with Polyply reproducing more reasonable properties of UHMWPE fibers.Additionally,tensile simulations showed that orientation and crystallinity greatly impact Young's modulus more than molecular weight.Energy decomposition indicated that higher molecular weights lead to covalent bonds that can withstand more energy during stretching,thus increasing breaking strength.Combining simulations with machine learning,we found that orientation has the most significant impact on Young's modulus,contributing 60%,and molecular weight plays the most crucial role in determining the breaking strength,accounting for 65%.This study provides a theoretical basis and guidelines for enhancing UHMWPE's modulus and strength.
基金supported by the National Natural Science Foundation of China (Grant Nos.52505554,52575571)the Postdoctoral Fellowship Program of CPSF (Grant No.GZB20250348)。
文摘Accurate mechanical modeling is essential for robotic belt grinding(RBG), a process characterized by compliant contact mechanisms that make force prediction particularly challenging. However, existing mechanical models predominantly focus on macroscale compliance while neglecting grain-scale compliant motion. Moreover, abrasive grains are typically idealized as regular shapes, overlooking the inherent stochasticity of real grain geometries. This study proposes a shapeequivalence method for modeling stochastic abrasive grains and develops a multiscale compliant force model for RBG. Specifically, an individual grain is represented as a polygonal pyramid with stochastic edges that is mathematically equivalent to a cone;this method unifies the treatment of grain geometries and streamlines the modeling process. The mathematical equivalence relationship for random grain shapes is further derived based on a grain-compliant contact model. By integrating grain geometric characteristics and progressive grain wear, an analytical mechanical model that captures both the static contact force and dynamic grinding force is established, thereby describing the transition from grain-workpiece compliant interaction to belt-workpiece elastic contact. Grinding experiments were conducted using abrasive belts with different grain shape distributions to validate the model. The results demonstrated reliable predictions of the tangential grinding force and its component characteristics. Additional analyses were performed to reveal how the tangential grinding force varies with wear time and grinding parameters.
基金funded by the National Natural Science Foundation of China(Nos.52422403 and U22A20166)the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(No.2024ZD1003903)+1 种基金the Department of Science and Technology of Guangdong Province(No.2019ZT08G315)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012654).
文摘Understanding the mechanical behavior of diagenetic mineral granules and interfaces in granite provides essential experimental references for constructing micromechanical models of granite.The micromechanical behavior of Yanshanian granite is investigated using scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS)and nanoindentation tests.The results demonstrate transitional mechanical properties at mineral interfaces.The elastic modulus and hardness exhibit intermediate values between adjacent mineral phases.The higher plasticity indices at the interfaces suggest higher plastic deformation capacity of hard-phase minerals in these regions.Additionally,fracture toughness measurements of minerals and interfaces were obtained,with interfacial values ranging from 0.90 to 1.63 MPa·m^(0.5).The analysis of mechanical property relationships shows a significant positive linear correlation between rock-scale elastic modulus and fracture toughness.However,this correlation is substantially lower at the mineral scale,demonstrating a scale effect in the relationship of different mechanical properties.
文摘On May 9,2025 on the campus of the University of Science and Technology of China(USTC),Chinese Academy of Sciences(CAS),an exhibition was unveiled to celebrate the UN International Year of Quantum Science and Technology(IYQ)-a one-year-long worldwide event in memory of the founding of quantum mechanics(QM).
基金supported by the Australian Research Council(Grant No.IC190100020)the Australian Research Council Indus〓〓try Fellowship(Grant No.IE230100435)the National Natural Science Foundation of China(Grant Nos.12032014 and T2488101)。
文摘The integration of physics-based modelling and data-driven artificial intelligence(AI)has emerged as a transformative paradigm in computational mechanics.This perspective reviews the development and current status of AI-empowered frameworks,including data-driven methods,physics-informed neural networks,and neural operators.While these approaches have demonstrated significant promise,challenges remain in terms of robustness,generalisation,and computational efficiency.We delineate four promising research directions:(1)Modular neural architectures inspired by traditional computational mechanics,(2)physics informed neural operators for resolution-invariant operator learning,(3)intelligent frameworks for multiphysics and multiscale biomechanics problems,and(4)structural optimisation strategies based on physics constraints and reinforcement learning.These directions represent a shift toward foundational frameworks that combine the strengths of physics and data,opening new avenues for the modelling,simulation,and optimisation of complex physical systems.
基金supported by the National Natural Science Foundation of China(no.42277122)the Science Foun-dation of the China University of Petroleum,Beijing(No.2462024BJRC013).
文摘In recent years,large language models(LLMs)have demonstrated immense potential in practical applications to enhance work efficiency and decision-making capabilities.However,specialized LLMs in the oil and gas engineering area are rarely developed.To aid in exploring and developing deep and ultra-deep unconventional reservoirs,there is a call for a personalized LLM on oil-and gas-related rock mechanics,which may handle complex professional data and make intelligent predictions and decisions.To that end,herein,we overview general and industry-specific LLMs.Then,a systematic workflow is proposed for building this domain-specific LLM for oil and gas engineering,including data collection and processing,model construction and training,model validation,and implementation in the specific domain.Moreover,three application scenarios are investigated:knowledge extraction from textural resources,field operation with multidisciplinary integration,and intelligent decision assistance.Finally,several challenges in developing this domain-specific LLM are highlighted.Our key findings are that geological surveys,laboratory experiments,field tests,and numerical simulations form the four original sources of rock mechanics data.Those data must flow through collection,storage,processing,and governance before being fed into LLM training.This domain-specific LLM can be trained by fine-tuning a general open-source LLM with professional data and constraints such as rock mechanics datasets and principles.The LLM can then follow the commonly used training and validation processes before being implemented in the oil and gas field.However,there are three primary challenges in building this domain-specific LLM:data standardization,data security and access,and striking a compromise between physics and data when building the model structure.Some of these challenges are administrative rather than technical,and overcoming those requires close collaboration between the different interested parties and various professional practitioners.
基金support from the China Scholarship Council(CSC No.201700260207)Swedish Iron and Steel Research Office(Jernkontoret)The EIT RawMaterials Upscaling project EndureIT(No.18317)is acknowledged by PH and WM for financial support.
文摘The low-temperature embrittlement limits the service temperature of ferritic and duplex stainless steels.The effects of alloying elements added to Fe-Cr binary system on the low-temperature embrittlement have been reviewed critically.Prior literature on the underlying phase transformation,i.e.,phase separation(PS)and changes of mechanical properties,is surveyed.The available literature indicates that the rate of PS is accelerated by Ni or Co in Fe-Cr binary system.The increased kinetics of PS also lead to an enhanced hardening rate during aging for Ni and Co alloyed Fe-Cr alloys.In low Cr(<17 wt.%)ferritic alloys,the additions of Al or Co can reduce embrittlement because these elements contribute to lowering the driving force for PS.The influence of other alloying elements such as Mo,Cu,Mn,Nb,and Ti is inconclusive but also discussed here.Thermodynamic and kinetic calculations were performed to evaluate current CALPHAD databases and to further investigate the thermodynamic and kinetic reasons for the effect of the additional alloying elements added to Fe-Cr alloy on PS.Some indications were provided for improving physically-based predictions of low-temperature embrittlement as well as opportunities to mitigate the phenomenon by alloying.
基金supported by Science Project of PetroChina Southwest Oil&Gas field Company,China(Grant.No:2024D112-01-02).
文摘Conventional geostress evaluation methods often assume static rock properties and neglect the dynamic degradation of mechanical parameters caused by damage evolution during drilling and fracturing processes,which significantly limits prediction accuracy.To address this gap,this study develops a multiphysics-coupled numerical framework integrating COMSOL Multiphysics and MATLAB,grounded in damage mechanics theory,to quantitatively investigate the control mechanism of progressive rock damage on geostress redistribution.By establishing a damage constitutive model coupled with thermo-hydro-mechanical interactions,we simulate the dynamic evolution of rock damage and its impact on stress field reorganization during wellbore operations.Key results demonstrate that(1)incorporating damage evolution leads to substantial deviations in both the magnitude and spatial distribution of geostress,with stress perturbations highly localized within damage zones;(2)changes in mechanical parameters-particularly elastic modulus and permeability-dominate stress adjustments,with heightened sensitivity in formations with low elastic moduli and high permeability;and(3)Poisson's ratio has a negligible influence,whereas permeability variation becomes critically important in low-stiffness formations.Field validation via leakage case analyses in the Wujiaping Formation confirms that the proposed method significantly enhances prediction accuracy compared with conventional approaches.This work elucidates the multiscale interdependency between damage and stress evolution by offering a physics-based framework to optimize drilling and stimulation design in heterogeneous reservoirs.
文摘We are pleased to introduce this special thematic section on Nanofluid Mechanics and Heat Transfer that is being included in Acta Mechanica Sinica(AMS).This thematic issue consists of 6 papers selected from papers that were presented at the 18th International Symposium on Numer-ical Analysis of Fluid Flows,Heat and Mass Transfer-Nu-merical Fluids 2023,held in Heraklion,Crete Greece,11-17 September 2023,and invited through a general call.The symposium covers various subjects:from new numerical methods and fundamental research until engineering appli-cations,and it is a part of the International Conference of Numerical Analysis and Applied Mathematics(ICNAAM),held annually.
基金Sponsored by Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515111166)Development and Reform Commission of Shenzhen(Grant No.XMHT20220103004)+1 种基金Shenzhen Natural Science Fund(Grant No.GXWD20231130100351002)National Natural Science Foundation of China(Grant No.11932005).
文摘Multi⁃field coupling problems involving species transport,heat transfer,substance transformation,and mechanical deformation are prevalent in various scenarios,such as the curing of early⁃age concretes,the response of soft materials,the oxidation of metals,the lithiation and delithiation of lithium⁃ion batteries,and the self⁃healing of biological tissues.Thermo⁃chemo⁃mechanical coupling dynamics are common characteristics of these problems,making theoretical studies on such processes of significant importance.This study offers a thorough review of advanced theoretical models that address thermo⁃chemo⁃mechanical behavior of solid materials within the theoretical framework of non⁃equilibrium thermodynamics.First,we outline the thermo⁃chemo⁃mechanical coupling phenomena observed in various application scenarios.Then,the theoretical developments of classical continuum mechanics include the phase field method and peridynamics in the contexts of thermo⁃mechanical coupling,chemo⁃mechanical coupling,and thermo⁃chemo⁃mechanical coupling,respectively.Finally,challenges faced by thermo⁃chemo⁃mechanical coupling research are highlighted and prospects and directions for this field are also outlined.This paper helps to understand the history and trends in the development of thermo⁃chemo⁃mechanical coupling theory.
基金supported by the National Natural Science Foundation of China(Grant No.U2241273)the Beijing Municipal Natural Science Foundation(Grant No.Z240017)+3 种基金the 111 project(Grant No.B13003)the Fundamental Research Funds for the Central Universitiesthe China Scholarship Councilthe Academic Excellence Foundation of BUAA for PhD Students.
文摘The mechanical properties of biological soft tissues play a critical role in the study of biomechanics and the development of protective measures against human injury.Various testing techniques at different scales have been employed to characterize the mechanical behavior of soft tissues,which is essential for developing accurate tissue simulants and numerical models.This review comprehensively explores the mechanical properties of soft tissues,examining experimental methods,mechanical models,numerical simulations,and the progress in materials that mimic the mechanical performance of soft tissues.Finally,it reviews the damage and protection of human tissues under kinetic impacts,anticipating the future construction of soft tissue surrogate targets.The aim is to provide a systematic theoretical foundation and the latest advancements in the field,addressing the design,preparation,and quantitative modeling of biomimetic materials,thereby promoting the in-depth development of soft tissue mechanics and its applications.
基金supported by the specialized research projects of Huanjiang Laboratory.
文摘Graphene,a two-dimensional material with atomic thickness,holds significant importance in advancing the existing theories of solid mechanics.However,as an intersection of multiple scales,it poses challenges to experimental measurements of its mechanical behaviors.This review comprehensively discusses the recent achievements in experimental studies on the mechanics of graphene,focusing on sample preparation,loading design,and measurement techniques.Moreover,personal perspectives on the future development in this field are presented,aiming to provide insights and inspiration for researchers engaged in related studies.
基金Financial support of this work by the Technology Development program of China(Grant No.2022204B003)National Natural Science Foundation of China(12272083 and 12172078)the Fundamental Research Funds for the Central Universities(DUT24YJ136)is gratefully acknowledged.
文摘This paper presents a novel element differential method for modeling cracks in piezoelectric materials,aiming to simulate fracture behaviors and predict the fracture parameter known as the J-integral accurately.The method leverages an efficient collocation technique to satisfy traction and electric charge equilibrium on the crack surface,aligning internal nodes with piezoelectric governing equations without needing integration or variational principles.It combines the strengths of the strong form collocation and finite element methods.The J-integral is derived analytically using the equivalent domain integral method,employing Green's formula and Gauss's divergence theorem to transform line integrals into area integrals for solving two-dimensional piezoelectric material problems.The accuracy of the method is validated through comparison with three typical examples,and it offers fracture prevention strategies for engineering piezoelectric structures under different electrical loading patterns.
基金support from the National Natural Science Foundation of China(No.12472072)the Fundamental Research Funds for the Central Universities,China.
文摘In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle Fatigue(MLCF)life of perforated structures.First,fatigue tests are carried out on three center-perforated structures,aiming to assess their fatigue life under various strengthening conditions.These tests reveal significant variations in fatigue life,accompanied by an examination of crack initiation through the analysis of fatigue fracture surfaces.Second,an innovative fatigue life prediction methodology is applied to perforated structures,which not only forecasts the initiation of fatigue cracks but also traces the progression of damage within these structures.It leverages an elastoplastic constitutive model integrated with damage and a damage evolution model under cyclic loads.The accuracy of this approach is validated by comparison with test results,falling within the three times error band.Finally,we explore the impact of various strengthening techniques,including cross-sectional reinforcement and cold expansion,on the fatigue life and damage evolution of these structures.This is achieved through an in-depth comparative analysis of both experimental data and computational predictions,which provides valuable insights into the behavior of perforated structures under fatigue conditions in practical applications.
文摘As a core course for the Engineering Cost major at Chongqing Institute of Engineering,Engineering Mechanics shoulders the dual mission of cultivating students’mechanical thinking,engineering practical abilities,and professional qualities.Centered on the deep integration of the outcome-based education(OBE)concept and curriculum-based ideological and political education,this paper systematically elaborates on the reform paths and implementation strategies from four dimensions-reconstruction of teaching content,innovation of assessment mechanisms,integration of ideological and political elements,and construction of teaching resources-by drawing on the teaching reform practices of Engineering Mechanics courses at multiple universities.Through modular teaching content design,a competency-oriented diversified assessment system,and a method of integrating ideological and political education with local characteristics and engineering case studies,the teaching objectives of“knowledge transmission,ability cultivation,and value shaping”are achieved in a three-in-one manner.Practical results indicate that after the reform,students’engineering practical abilities have significantly improved,with a course objective achievement rate exceeding 0.73,a 23%increase in student satisfaction with the course,and a 35%year-on-year increase in the number of awards won in professional competitions,providing a replicable paradigm for the teaching reform of engineering courses.
基金Supported by the National Natural Science Foundation of China(NSFC)Major Project(51991362).
文摘Considering the three typical phase-change related rock mechanics phenomena during drilling and production in oil and gas reservoirs,which include phase change of solid alkane-related mixtures upon heating,sand liquefaction induced by sudden pressure release of the over-pressured sand body,and formation collapse due to gasification of pore fillings from pressure reduction,this study first systematically analyzes the progress of theoretical understanding,experimental methods,and mathematical representation,then discusses the engineering application scenarios corresponding to the three phenomena and reveals the mechanical principles and application effectiveness.Based on these research efforts,the study further discusses the significant challenges,potential developmental trends,and research approaches that require urgent exploration.The findings disclose that various phase-related rock mechanics phenomena require specific experimental and mathematical methods that can produce multi-field coupling mechanical mechanisms,which will eventually instruct the control on resource exploitation,evaluation on disaster level,and analysis of formation stability.To meet the development needs of the principle,future research efforts should focus on mining more phase-change related rock mechanics phenomena during oil and gas resources exploitation,developing novel experimental equipment,and using techniques of artificial intelligence and digital twins to implement real-time simulation and dynamic visualization of phase-change related rock mechanics.
文摘Significant advances in battery and fuel cell technologies over the past decade have catalyzed the transition toward electrified transportation systems and large-scale renewable energy integration.Concurrent with these developments,the interdisciplinary role of mechanics has emerged as a critical research frontier.
