International Journal of Solids and Structures最新文献_第10页

Investigation of unidirectional vibration isolation and nonreciprocal design of axial elastic waves based on topological pumping theory

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-09 DOI: 10.1016/j.ijsolstr.2024.113192

Zixun Lu , Hui Chen , Lingyun Yao

In this work, a spiral structure (SS) based on the nonreciprocal waveguide theory of adiabatic evolution principle is designed, which can generate dynamic boundaries on a rotation shaft. The spatiotemporal topological pumping formed by SS can achieve nonreciprocal transmission of elastic waves in shaft, and the transmission can achieve unidirectional isolation of shaft vibration. Firstly, transfer matrix method (TMM) is used to theoretically derive the continuity at two-phase spiral periodic shaft structure (SPSS) medium. Then, finite element method (FEM) is utilized to calculate energy bands and frequency response functions of SPSS. Next, the calculations results obtained by FEM are used to analyze the influence of material parameters, geometric dimensions and other factors on band gap, and SPSS of rotation is used to confirm the variation of topological edge modes produced by spatiotemporal pumping. Finally, realistic shaft model and analytical parameters are combined to determine the dimensional parameters and materials of unidirectional vibration isolation shaft, vibration transmission characteristics of spiral shaft are obtained by numerical simulation, and its unidirectional vibration isolation performance is verified through experiment. The results show that SS can achieve spatiotemporal topological pumping function at a certain modulation speed, when the band gap is deflected in a specific frequency range, elastic waves can be transmitted unidirectional in deflected frequency range, the dynamic spiral shaft has a good unidirectional vibration isolation effect when the shaft is modulated in the reverse direction, and changing helical angular velocity can tune frequency range of nonreciprocal transmission of elastic waves. The design can provide a theoretical basis for engineering application of unidirectional vibration isolation bushing in wide frequency range.

{"title":"Investigation of unidirectional vibration isolation and nonreciprocal design of axial elastic waves based on topological pumping theory","authors":"Zixun Lu , Hui Chen , Lingyun Yao","doi":"10.1016/j.ijsolstr.2024.113192","DOIUrl":"10.1016/j.ijsolstr.2024.113192","url":null,"abstract":"<div><div>In this work, a spiral structure (SS) based on the nonreciprocal waveguide theory of adiabatic evolution principle is designed, which can generate dynamic boundaries on a rotation shaft. The spatiotemporal topological pumping formed by SS can achieve nonreciprocal transmission of elastic waves in shaft, and the transmission can achieve unidirectional isolation of shaft vibration. Firstly, transfer matrix method (TMM) is used to theoretically derive the continuity at two-phase spiral periodic shaft structure (SPSS) medium. Then, finite element method (FEM) is utilized to calculate energy bands and frequency response functions of SPSS. Next, the calculations results obtained by FEM are used to analyze the influence of material parameters, geometric dimensions and other factors on band gap, and SPSS of rotation is used to confirm the variation of topological edge modes produced by spatiotemporal pumping. Finally, realistic shaft model and analytical parameters are combined to determine the dimensional parameters and materials of unidirectional vibration isolation shaft, vibration transmission characteristics of spiral shaft are obtained by numerical simulation, and its unidirectional vibration isolation performance is verified through experiment. The results show that SS can achieve spatiotemporal topological pumping function at a certain modulation speed, whenthe band gap is deflected in a specific frequency range, elastic waves can be transmitted unidirectional in deflected frequency range, the dynamic spiral shaft has a good unidirectional vibration isolation effect when the shaft is modulated in the reverse direction, and changing helical angular velocity can tune frequency range of nonreciprocal transmission of elastic waves. The design can provide a theoretical basis for engineering application of unidirectional vibration isolation bushing in wide frequency range.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113192"},"PeriodicalIF":3.4,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Symmetry breaking and dynamic characteristics of post-buckling in bilayer van der Waals structures

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-09 DOI: 10.1016/j.ijsolstr.2024.113190

Guangfei Zhu, Rumeng Liu, Lifeng Wang

The van der Waals (vdW) interaction plays a crucial role in the mechanical properties, including bending and buckling, of layered 2D materials, directly affecting their performance as flexible devices. This study systematically investigates the symmetry breaking and dynamic characteristics of post-buckling in bilayer vdW structures caused by the local atomic positions’ dependence of vdW interactions. Our observations reveal that the buckling configuration of bilayer molybdenum disulfide (MoS₂) exhibits a significant dependence on the direction of applied load. When compressed along the zigzag direction, the post-buckling configuration is symmetric. In contrast, compression along the armchair direction results in a significant asymmetric post-buckling configuration. Additionally, the asymmetric buckling configuration strongly correlates with the length of the structure and the magnitude of compressive strain. Combining molecular dynamics simulations and a continuum-discrete model, it is found that this symmetry breaking in buckling results from anisotropic and non-uniform shear and sliding between atomic layers. Moreover, under biaxial compression, bilayer circular MoS₂ demonstrates post-buckling configurations and thermal vibration modes markedly distinct from monolayer MoS₂. These configurations are closely associated with the initial stacking orders of bilayer MoS₂. In particular, effective modulation of asymmetry is achieved by twisting the bilayer structure, offering insights into controlling buckling behavior. These findings provide novel perspectives for describing and addressing buckling issues in layered vdW structures and offer guidance for designing and optimizing vdW structure devices.

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引用次数: 0

Buckling of plane frames under unilateral kinematic constraints

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-07 DOI: 10.1016/j.ijsolstr.2024.113185

F.F. de Almeida , A. Pinto da Costa , F.M.F. Simões

This work deals with the buckling of elastic frames in the presence of supports that restrict motion (either translational or rotational) in one direction only: the so called “unilateral supports”. A new method is presented for computing the bifurcation loads and modes of kinematically constrained, slender reticulated structures, using a single finite element per bar for stability analysis. One considers exact finite elements of axially loaded bars that may be either (a) compressed, (b) with no axial force or (c) tensioned. The numerical computation of bifurcation loads and buckling modes is based on a doubly nonlinear eigenvalue problem: (i) nonlinear because the load parameter appears scattered in the several stability functions (that are circular trigonometric or hyperbolic trigonometric, respectively for compression or tension) and (ii) nonlinear due to the complementarity conditions corresponding to the unilateral support conditions. The new method, which uses a single element per bar, is validated by comparing cases with and without unilateral supports to numerical and analytical results from the literature.

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引用次数: 0

Emergence of tension–compression asymmetry from a complete phase-field approach to brittle fracture

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-03 DOI: 10.1016/j.ijsolstr.2024.113170

Chang Liu, Aditya Kumar

The classical variational approach to brittle fracture propagation does not distinguish between strain energy accumulation in tension versus compression and consequently results in physically unrealistic cracking under compression. A variety of energy splits have been proposed as a possible remedy. However, a unique energy split that can describe this asymmetry for general loading conditions has not been found. The main objective of this paper is to show that a complete phase-field theory of brittle fracture nucleation and propagation, one that accounts for the material strength at large, can naturally capture the tension–compression asymmetry in crack propagation without an energy split. One such theory has been recently proposed by Kumar et al. (2018). Over the past few years, several studies have shown that this theory is capable of accurately describing fracture nucleation and propagation for materials soft and hard under arbitrary monotonic loading conditions. However, a systematic study of the tension–compression asymmetry that emerges from this theory has not yet been reported. This paper does precisely that. In particular, this paper reports a comprehensive study of crack propagation in two problems, one involving a symmetric tension–compression state and the other involving larger compressive stresses at the crack tip. The results are compared with popular energy splits used in literature. The results show that, remarkably, for the second problem, only the complete theory is able to produce experimentally consistent results.

{"title":"Emergence of tension–compression asymmetry from a complete phase-field approach to brittle fracture","authors":"Chang Liu, Aditya Kumar","doi":"10.1016/j.ijsolstr.2024.113170","DOIUrl":"10.1016/j.ijsolstr.2024.113170","url":null,"abstract":"<div><div>The classical variational approach to brittle fracture propagation does not distinguish between strain energy accumulation in tension versus compression and consequently results in physically unrealistic cracking under compression. A variety of energy splits have been proposed as a possible remedy. However, a unique energy split that can describe this asymmetry for general loading conditions has not been found. The main objective of this paper is to show that a complete phase-field theory of brittle fracture nucleation and propagation, one that accounts for the material strength at large, can naturally capture the tension–compression asymmetry in crack propagation without an energy split. One such theory has been recently proposed by Kumar et al. (2018). Over the past few years, several studies have shown that this theory is capable of accurately describing fracture nucleation and propagation for materials soft and hard under arbitrary monotonic loading conditions. However, a systematic study of the tension–compression asymmetry that emerges from this theory has not yet been reported. This paper does precisely that. In particular, this paper reports a comprehensive study of crack propagation in two problems, one involving a symmetric tension–compression state and the other involving larger compressive stresses at the crack tip. The results are compared with popular energy splits used in literature. The results show that, remarkably, for the second problem, only the complete theory is able to produce experimentally consistent results.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113170"},"PeriodicalIF":3.4,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Unified characterization of failure surfaces and golden-ratio ductile-to-brittle classification for isotropic materials

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-03 DOI: 10.1016/j.ijsolstr.2024.113184

Sontipee Aimmanee, Pijak Tiraviriyaporn

The failure surface, often referred to as the failure angle, defines the specific planar orientation within a material that reaches its load-carrying capacity, represented by material strengths. Analyzing this critical surface is elemental for material characterization, providing profound insights into ductility and brittleness. Despite the diversity of methodologies employed for determining the failure plane from various criteria, a universally accepted theory that systematically governs this characteristic across a broad spectrum of isotropic materials remains elusive. Therefore, this paper aims to develop a unified framework for predicting the failure surface for all homogeneous isotropic solids by considering the convergence of three key material constitutive models: elasticity, failure, and plasticity. A universal energy-based failure criterion is utilized to determine failure angles under fundamental loading scenarios, including uniaxial tension, uniaxial compression, pure shear, and biaxial tension–compression. The sliding, splitting, and crushing behaviors are obtained from the direct and shear strain increments, while the ratio of the two strain increments elucidates the dominant roles in ductile and brittle failure modes. For the first time, the developed theory links the failure angle to Poisson’s ratio, and uniaxial strength properties, unveiling a connection between intrinsic material parameters and extrinsic ductility and brittleness induced by external loadings. The failure angle representing ductile-to-brittle transition under the applied stresses in the principal stress coordinates is shown to be directly related to the golden ratio and independent of loading types. This research addresses longstanding mysteries by providing a deeper understanding of the physics of solids and suggesting potential applications with a phase-field model for predicting the evolving fracture direction.

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引用次数: 0

A response surface function method to characterize residual stress and cumulative plastic strain through indentation

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-02 DOI: 10.1016/j.ijsolstr.2024.113176

Hui Chen , Pascale Kanouté , Manuel François

Shot peening is a mechanical surface treatment used to improve the material fatigue performance by introducing compressive residual stress and work hardening. In order to characterize the residual stress (RS) and cumulative plastic strain (PS) of the treated surface simultaneously using the instrumented indentation technique, a Response Surface Function method is proposed in this work using a calibration by finite element simulations. The method is first verified numerically, and the results indicate that the determined values can accurately represent the input values, which shows the possibility of experimental application. The proposed method is then applied experimentally on a nickel-based alloy, Inconel 625. For validation, the solved profiles are compared with the profiles measured by X-ray diffraction (XRD). Although there is a difference between the profiles obtained by these two measurement techniques, the proposed method makes an advance on the characterization of residual stress and cumulative plastic strain simultaneously. It has demonstrated its feasibility, indicating its potential for practical application.

{"title":"A response surface function method to characterize residual stress and cumulative plastic strain through indentation","authors":"Hui Chen , Pascale Kanouté , Manuel François","doi":"10.1016/j.ijsolstr.2024.113176","DOIUrl":"10.1016/j.ijsolstr.2024.113176","url":null,"abstract":"<div><div>Shot peening is a mechanical surface treatment used to improve the material fatigue performance by introducing compressive residual stress and work hardening. In order to characterize the residual stress (RS) and cumulative plastic strain (PS) of the treated surface simultaneously using the instrumented indentation technique, a Response Surface Function method is proposed in this work using a calibration by finite element simulations. The method is first verified numerically, and the results indicate that the determined values can accurately represent the input values, which shows the possibility of experimental application. The proposed method is then applied experimentally on a nickel-based alloy, Inconel 625. For validation, the solved profiles are compared with the profiles measured by X-ray diffraction (XRD). Although there is a difference between the profiles obtained by these two measurement techniques, the proposed method makes an advance on the characterization of residual stress and cumulative plastic strain simultaneously. It has demonstrated its feasibility, indicating its potential for practical application.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113176"},"PeriodicalIF":3.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 analysis of mixed mode bending of adhesive-bonded and hybrid honeycomb core sandwich structures

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-12-02 DOI: 10.1016/j.ijsolstr.2024.113177

A. Kumar , P.J. Saikia , R.Ganesh Narayanan , N. Muthu

This study investigates the potential of a hybrid joining method, called friction stir spot welding with disc and adhesive bonding (FSSW_D_AB), for bonding honeycomb core sandwich structures, offering an alternative to traditional adhesive bonding (AB) sandwich structures. The research focuses on the manufacturing of these hybrid joints and evaluating their performance compared to conventional adhesive bonding (AB) methods. Mixed Mode Bending (MMB) tests were performed to assess the mechanical behaviour of the joints under different loading conditions. Additionally, numerical analysis using cohesive zone modeling (CZM) was performed using both a honeycomb core with a cohesive layer and the homogenized core with an equivalent cohesive layer. The study reveals that the hybrid joining method significantly enhances the performance of honeycomb sandwich structures. The good agreement between the numerical predictions and the experimental results for all types of joints showed the usefulness of the proposed numerical model. However, the FEM-based stress and damage analyses of the joints provided crucial results on normal and shear stress distributions and delamination.

{"title":"Experimental and numerical analysis of mixed mode bending of adhesive-bonded and hybrid honeycomb core sandwich structures","authors":"A. Kumar , P.J. Saikia , R.Ganesh Narayanan , N. Muthu","doi":"10.1016/j.ijsolstr.2024.113177","DOIUrl":"10.1016/j.ijsolstr.2024.113177","url":null,"abstract":"<div><div>This study investigates the potential of a hybrid joining method, called friction stir spot welding with disc and adhesive bonding (FSSW_D_AB), for bonding honeycomb core sandwich structures, offering an alternative to traditional adhesive bonding (AB) sandwich structures. The research focuses on the manufacturing of these hybrid joints and evaluating their performance compared to conventional adhesive bonding (AB) methods. Mixed Mode Bending (MMB) tests were performed to assess the mechanical behaviour of the joints under different loading conditions. Additionally, numerical analysis using cohesive zone modeling (CZM) was performed using both a honeycomb core with a cohesive layer and the homogenized core with an equivalent cohesive layer. The study reveals that the hybrid joining method significantly enhances the performance of honeycomb sandwich structures. The good agreement between the numerical predictions and the experimental results for all types of joints showed the usefulness of the proposed numerical model. However, the FEM-based stress and damage analyses of the joints provided crucial results on normal and shear stress distributions and delamination.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113177"},"PeriodicalIF":3.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 modeling investigation on anisotropic plastic flow of metal plates under nonproportional loading conditions

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-11-30 DOI: 10.1016/j.ijsolstr.2024.113174

Huachao Yang , Wen Zhang , Xincun Zhuang , Zhen Zhao

The plastic deformation behavior of metal plates has been proved to be affected by loading paths. Plastic flow is a critical component in the mechanical description of plastic deformation, like yield and hardening. In this work, the anisotropic plastic flow of two metal plates (16MnCr5 and S420MC) under non-proportional loading conditions was investigated. Large specimens manufactured along different orientations were pre-tensioned up to various strain levels; subsequently, small uniaxial tensile specimens were cut from the pre-tensioned specimens along different orientations with the interval of 15°, and then loaded to rupture. Meanwhile, the r-value, a measure of anisotropic plastic flow, was recorded. Result shows that for the studied plates which had constant r-value in the monotonic uniaxial tensile tests, a downward evolution of the r-value against plastic strain was observed when the Schmitt angle of two stage loading directions was greater than 90°. As the plastic strain in the subsequent loading stage accumulated, the r-value dropped from a higher level to its original level within a strain range about 6.0%. Based on the transient r-value evolution, a HEXAH-based evolutionary plastic potential model was constructed within the framework of non-associated flow (non-AF) theory. In the model, a local ellipse-shape distortion of the plastic potential surface was defined during plastic deformation process and when the Schmitt angel exceeded 90°, such distortion caused a downward evolution of the r-value in the subsequent deformation. The calibration result indicates that the model could reproduce the transient r-value response relevant to loading path change. The proposed evolutionary plastic potential model can be applied together with different anisotropic hardening models in the non-AF theory to give a detailed description of the plastic deformation behavior and hopefully provide a solution for the accurate simulation of the complex sheet metal forming process.

{"title":"Experimental and modeling investigation on anisotropic plastic flow of metal plates under nonproportional loading conditions","authors":"Huachao Yang , Wen Zhang , Xincun Zhuang , Zhen Zhao","doi":"10.1016/j.ijsolstr.2024.113174","DOIUrl":"10.1016/j.ijsolstr.2024.113174","url":null,"abstract":"<div><div>The plastic deformation behavior of metal plates has been proved to be affected by loading paths. Plastic flow is a critical component in the mechanical description of plastic deformation, like yield and hardening. In this work, the anisotropic plastic flow of two metal plates (16MnCr5 and S420MC) under non-proportional loading conditions was investigated. Large specimens manufactured along different orientations were pre-tensioned up to various strain levels; subsequently, small uniaxial tensile specimens were cut from the pre-tensioned specimens along different orientations with the interval of 15°, and then loaded to rupture. Meanwhile, the <em>r-</em>value, a measure of anisotropic plastic flow, was recorded. Result shows that for the studied plates which had constant <em>r</em>-value in the monotonic uniaxial tensile tests, a downward evolution of the <em>r</em>-value against plastic strain was observed when the Schmitt angle of two stage loading directions was greater than 90°. As the plastic strain in the subsequent loading stage accumulated, the <em>r</em>-value dropped from a higher level to its original level within a strain range about 6.0%. Based on the transient <em>r</em>-value evolution, a HEXAH-based evolutionary plastic potential model was constructed within the framework of non-associated flow (non-AF) theory. In the model, a local ellipse-shape distortion of the plastic potential surface was defined during plastic deformation process and when the Schmitt angel exceeded 90°, such distortion caused a downward evolution of the <em>r-</em>value in the subsequent deformation. The calibration result indicates that the model could reproduce the transient <em>r-</em>value response relevant to loading path change. The proposed evolutionary plastic potential model can be applied together with different anisotropic hardening models in the non-AF theory to give a detailed description of the plastic deformation behavior and hopefully provide a solution for the accurate simulation of the complex sheet metal forming process.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113174"},"PeriodicalIF":3.4,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Thermomechanical performance of double-phase periodic and graded architected materials: Numerical and explainability analysis

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-11-30 DOI: 10.1016/j.ijsolstr.2024.113159

Dimitrios C. Rodopoulos , Nikolaos Karathanasopoulos

The work investigates the effective thermomechanical performance of double-phase architected materials as a function of their inner design. The effective thermal conductivity, Young’s and shear moduli of double-phase composites, engineered with a wide range of Gielis’-formula-based topological architectures are analyzed, deriving analytical expressions for their effective performance. Thereupon, the effect of the addition of a second thermally isolating or conductive and mechanically soft or stiff phase is quantified for different phase combinations, including metal–metal, metal–ceramic or metal–epoxy designs, material pairs encountered in engineering practice. Moreover, the impact of material grading is assessed, establishing and quantifying differences among the effective mechanical and thermal attributes. It is shown that the Young’s modulus is mainly controlled by the shape of the second phase, while the effective thermal conductivity arises as a combination of the underlying pattern and phase properties. High-fidelity neural network (NN) models are developed and used as a basis for interpretability, SHapley Additive exPlanations (SHAP) analysis. Highly nonlinear dependencies on the inner design features are reported, with feature interactions well-beyond the bounds of single-phase material designs. The role of shape effects is quantified as more prominent for comparatively low conductivity and soft second phase designs. In such a space, the Young’s

\hat{E}

and shear

\hat{G}

modulus are 33% and 100% more sensitive to the inner structural pattern than the effective thermal conductivity

\hat{k}

. The relative significance of topology is substantially mitigated for composites with comparable phase conductivities and stiffness ratios, with importance values that are nearly seven times lower than the ones computed for the second phase volumetric content.

{"title":"Thermomechanical performance of double-phase periodic and graded architected materials: Numerical and explainability analysis","authors":"Dimitrios C. Rodopoulos , Nikolaos Karathanasopoulos","doi":"10.1016/j.ijsolstr.2024.113159","DOIUrl":"10.1016/j.ijsolstr.2024.113159","url":null,"abstract":"<div><div>The work investigates the effective thermomechanical performance of double-phase architected materials as a function of their inner design. The effective thermal conductivity, Young’s and shear moduli of double-phase composites, engineered with a wide range of Gielis’-formula-based topological architectures are analyzed, deriving analytical expressions for their effective performance. Thereupon, the effect of the addition of a second thermally isolating or conductive and mechanically soft or stiff phase is quantified for different phase combinations, including metal–metal, metal–ceramic or metal–epoxy designs, material pairs encountered in engineering practice. Moreover, the impact of material grading is assessed, establishing and quantifying differences among the effective mechanical and thermal attributes. It is shown that the Young’s modulus is mainly controlled by the shape of the second phase, while the effective thermal conductivity arises as a combination of the underlying pattern and phase properties. High-fidelity neural network (NN) models are developed and used as a basis for interpretability, SHapley Additive exPlanations (SHAP) analysis. Highly nonlinear dependencies on the inner design features are reported, with feature interactions well-beyond the bounds of single-phase material designs. The role of shape effects is quantified as more prominent for comparatively low conductivity and soft second phase designs. In such a space, the Young’s <span><math><mover><mrow><mi>E</mi></mrow><mrow><mo>ˆ</mo></mrow></mover></math></span> and shear <span><math><mover><mrow><mi>G</mi></mrow><mrow><mo>ˆ</mo></mrow></mover></math></span> modulus are 33% and 100% more sensitive to the inner structural pattern than the effective thermal conductivity <span><math><mover><mrow><mi>k</mi></mrow><mrow><mo>ˆ</mo></mrow></mover></math></span>. The relative significance of topology is substantially mitigated for composites with comparable phase conductivities and stiffness ratios, with importance values that are nearly seven times lower than the ones computed for the second phase volumetric content.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113159"},"PeriodicalIF":3.4,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 volume of fluid method for structural damage identification

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2024-11-29 DOI: 10.1016/j.ijsolstr.2024.113160

Qi Zhu, Zhenghuan Wang, Xiaojun Wang

In the field of engineering, Structural Health Monitoring (SHM) is crucial for identifying damage in continuum structures. Traditional damage identification methods often reformulate the problem as an inverse problem, leveraging frequency-based approaches. While the effectiveness of these methods is well-established, they have certain limitations. Specifically, they require prior knowledge of the topology of damaged regions, which can complicate and extend the detection process. Furthermore, incorrect initial conditions can lead to inaccuracies in identifying these damaged regions. To address these issues, we propose an innovative damage identification method utilizing the Volume of Fluid (VOF) approach. This method transforms the conventional inverse problem of natural frequencies into a shape optimization problem by representing damaged regions as a VOF function. The VOF method simplifies the identification process into the convection motion of material density, governed by a Hamilton-Jacobi equation. We present a comprehensive mathematical model, detail the numerical implementation, and validate the method through various examples. Moreover, numerical comparisons with similar methods are included in the case studies to demonstrate the feasibility of the approach proposed in this paper. Our results demonstrate the effectiveness and accuracy of this approach in identifying damage without dependency on initial topology, providing a valuable alternative to traditional methods.

{"title":"A volume of fluid method for structural damage identification","authors":"Qi Zhu, Zhenghuan Wang, Xiaojun Wang","doi":"10.1016/j.ijsolstr.2024.113160","DOIUrl":"10.1016/j.ijsolstr.2024.113160","url":null,"abstract":"<div><div>In the field of engineering, Structural Health Monitoring (SHM) is crucial for identifying damage in continuum structures. Traditional damage identification methods often reformulate the problem as an inverse problem, leveraging frequency-based approaches. While the effectiveness of these methods is well-established, they have certain limitations. Specifically, they require prior knowledge of the topology of damaged regions, which can complicate and extend the detection process. Furthermore, incorrect initial conditions can lead to inaccuracies in identifying these damaged regions. To address these issues, we propose an innovative damage identification method utilizing the Volume of Fluid (VOF) approach. This method transforms the conventional inverse problem of natural frequencies into a shape optimization problem by representing damaged regions as a VOF function. The VOF method simplifies the identification process into the convection motion of material density, governed by a Hamilton-Jacobi equation. We present a comprehensive mathematical model, detail the numerical implementation, and validate the method through various examples. Moreover, numerical comparisons with similar methods are included in the case studies to demonstrate the feasibility of the approach proposed in this paper. Our results demonstrate the effectiveness and accuracy of this approach in identifying damage without dependency on initial topology, providing a valuable alternative to traditional methods.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"309 ","pages":"Article 113160"},"PeriodicalIF":3.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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