Continuum Mechanics and Thermodynamics最新文献

{"title":"Mathematical modelling of stability problems for thin transversally graded cylindrical shells","authors":"B. Tomczyk,&nbsp;M. Gołąbczak,&nbsp;E. Kubacka,&nbsp;V. Bagdasaryan","doi":"10.1007/s00161-024-01322-3","DOIUrl":"10.1007/s00161-024-01322-3","url":null,"abstract":"<div><p>The objects of consideration are thin linearly elastic Kirchhoff–Love-type open circular cylindrical shells having a functionally graded macrostructure and a tolerance-periodic microstructure in circumferential direction. The first aim of this contribution is to formulate and discuss <i>a new mathematical averaged non-asymptotic model for the analysis of selected stability problems for such shells</i>. As a tool of modelling we shall apply <i>the tolerance averaging technique</i>. The second aim is to derive and discuss <i>a new mathematical averaged asymptotic model</i>. This model will be formulated using <i>the consistent asymptotic modelling procedure</i>. The starting equations are the well-known governing equations of linear Kirchhoff–Love second-order theory of thin elastic cylindrical shells. For the functionally graded shells under consideration, the starting equations have highly oscillating, non-continuous and tolerance-periodic coefficients in circumferential direction, whereas equations of the proposed models have continuous and slowly-varying coefficients. Moreover, some of coefficients of the tolerance model equations depend on a microstructure size. It will be shown that in the framework of the tolerance model <i>not only the fundamental cell-independent, but also the new additional cell-dependent critical forces can be derived and analysed.</i></p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1661 - 1684"},"PeriodicalIF":1.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-024-01322-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141895358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of inverse problems for generalized elastic media: formulations, experiments, synthesis","authors":"Roberto Fedele,&nbsp;Luca Placidi,&nbsp;Francesco Fabbrocino","doi":"10.1007/s00161-024-01314-3","DOIUrl":"10.1007/s00161-024-01314-3","url":null,"abstract":"<div><p>Starting from the seminal works of Toupin, Mindlin and Germain, a wide class of generalized elastic models have been proposed via the principle of virtual work, by postulating expressions of the elastic energy enriched by additional kinematic descriptors or by higher gradients of the placement. More recently, such models have been adopted to describe phenomena which are not consistent with the Cauchy-Born continuum, namely the size dependence of apparent elastic moduli observed for micro and nano-objects, wave dispersion, optical modes and band gaps in the dynamics of heterogeneous media. For those structures the mechanical response is affected by surface effects which are predominant with respect to the bulk, and the scale of the external actions interferes with the characteristic size of the heterogeneities. Generalized continua are very often referred to as media with microstructure although a rigorous deduction is lacking between the specific microstructural features and the constitutive equations. While in the forward modelling predictions of the observations are provided, the actual observations at multiple scales can be used inversely to integrate some lack of information about the model. In this review paper, generalized continua are investigated from the standpoint of inverse problems, focusing onto three topics, tightly connected and located at the border between multiscale modelling and the experimental assessment, namely: (i) parameter identification of generalized elastic models, including asymptotic methods and homogenization strategies; (ii) design of non-conventional tests, possibly integrated with full field measurements and advanced modelling; (iii) the synthesis of meta-materials, namely the identification of the microstructures which fit a target behaviour at the macroscale. The scientific literature on generalized elastic media, with the focus on the higher gradient models, is fathomed in search of questions and methods which are typical of inverse problems theory and issues related to parameter estimation, providing hints and perspectives for future research.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1413 - 1453"},"PeriodicalIF":1.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-024-01314-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141895360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New approach to ({upalpha })-titanium mechanical properties enhancement by means of thermoplastic deformation in mid-temperature range","authors":"Jakub Bańczerowski,&nbsp;Marek Pawlikowski,&nbsp;Tomasz Płociński,&nbsp;Andrzej Zagórski,&nbsp;Sylwester Sawicki,&nbsp;Roman Gieleta","doi":"10.1007/s00161-024-01321-4","DOIUrl":"10.1007/s00161-024-01321-4","url":null,"abstract":"<div><p>Pure titanium due to its high corrosion resistance, low stiffness and good mechanical properties is commonly used in medicine for orthopaedic applications. However, its material properties (especially in the case of <span>({upalpha })</span>-titanium) require a further enhancement to fulfil its role. The thermoplastic deformation in mid-temperature is proposed as a method for microstructure improvement. Titanium samples were compressed in different temperatures and strain rates to determine the best conditions for grain fragmentation—the main factor responsible for strength and hardness increase. The thermoplastic stress–strain curves were registered. Then microstructure observations and electron backscatter analysis were performed on the chosen samples. Finally, mechanical response of the previously deformed material was obtained in room temperature compression tests. A significant grain fragmentation was recorded for the material deformed in 400 <span>(^{circ }hbox {C})</span>, at 0.1/s and 1/s strain rates. Desirable results were also noticed for the deformation performed at 500–600 <span>(^{circ }hbox {C})</span>. However, high temperatures (700–800 <span>(^{circ }hbox {C})</span>) and strain rates (10/s) resulted in dynamic recrystallization, causing undesirable grain growth. An increase in hardness was observed in all cases, with higher values recorded in lower deformation temperatures. Room temperature compression tests revealed slight increase of ductility.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1645 - 1660"},"PeriodicalIF":1.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-024-01321-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141895356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermo-oxidative aging of natural rubber: experimental study and a thermodynamically consistent mechanical-chemical-diffusion model","authors":"A. Jalalpour,&nbsp;J. Arghavani,&nbsp;R. Naghdabadi","doi":"10.1007/s00161-024-01317-0","DOIUrl":"10.1007/s00161-024-01317-0","url":null,"abstract":"<div><p>Elastomers have diverse properties that make them suitable for use in many industrial applications. Natural Rubber, in particular, is an attractive elastomer due to its desirable mechanical properties as well as lightweight compared to metals. However, due to the natural rubber structure, these elastomers are susceptible to heat, oxidation, and chemical compounds, which limits their potential use. In this paper, in order to study the behavior of natural rubber under thermo-oxidative aging, experiments, including continuous stress relaxation, creep, and intermittent tensile tests, are carried out on the samples. Based on the experimental results and using dynamic-network model, a mechanical-chemical-diffusion model is proposed to predict the changes in natural rubber properties during thermo-oxidative aging considering the effect of the natural rubber curing system. In the chemical part of the model, the two main process of aging, including chain scission and crosslinking, are modeled by using two internal variables. The proposed model is implemented using the finite element method to simulate experimental tests for the model verification. The comparisons demonstrate the proposed model ability to accurately simulate the various loading states under thermo-oxidative aging of natural rubber.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1579 - 1595"},"PeriodicalIF":1.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141891829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From approximation of dissipative systems to representative space-time volume elements for metamaterials","authors":"Olga Chekeres,&nbsp;Vladimir Salnikov,&nbsp;Francesco D’Annibale","doi":"10.1007/s00161-024-01318-z","DOIUrl":"10.1007/s00161-024-01318-z","url":null,"abstract":"<div><p>In this paper we present some relatively unexpected mathematical questions emerging from the idea to approximate dissipative mechanical systems using Lagrangian formalism. We also explain potential consequences of these constructions for definition of representative space-time volume elements in modelling of metamaterials.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1597 - 1605"},"PeriodicalIF":1.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141877666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface layer effect on high pressure phase growth in a bicrystal: phase field model and simulations","authors":"Seyed Hamed Mirmahdi,&nbsp;Mahdi Javanbakht,&nbsp;Emilio Barchiesi","doi":"10.1007/s00161-024-01316-1","DOIUrl":"10.1007/s00161-024-01316-1","url":null,"abstract":"<div><p>Effect of the external surface layer on the phase transition (PT) between the low pressure phase and high pressure phase (HPP) in a NiAl bicrystal is investigated. Using a phase field model, the external surface layer is included, within which the elastic properties and surface energy are properly distributed. After resolving a stationary layer, the coupled phase field and elasticity equations are solved to capture the HPP evolution. Residual stress concentrator is included as a shear band representing an inelastic shear strain. Due to the small grain size, the surface layer can influence the stress distribution and consequently, the critical inelastic shear strain <span>(gamma _{cr})</span> for the HPP growth. Above a certain applied pressure, the surface layer width <span>({Delta }_{{xi }})</span> shows no effect on <span>(gamma _{cr})</span>, e.g., <span>(P=10)</span> GPa for the grain size of L <span>(=)</span> 20 nm. For lower pressures, <span>(gamma _{cr})</span> increases as pressure reduces. Due to the interplay of size addition by the surface layer and size reduction by the transformation strain, <span>(gamma _{cr})</span> reduces versus <span>({Delta }_{{xi }})</span> and then increases for larger <span>({Delta }_{{xi }})</span>. For smaller grain sizes, the surface layer effect is promoted as it is imposed to a larger transformation work. The lowest <span>(gamma _{cr})</span> is obtained for <span>(P=19)</span> GPa, in good agreement with the theoretical pressure of 20 GPa. Combining the external shear on pressure adds an extra shear term to the transformation work, which allows for the relaxation of the shear band and results in a nonlinear reduction of the PT pressure versus applied shear.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1565 - 1577"},"PeriodicalIF":1.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141755071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid discrete-to-continuum viscoelastic viscoplasticity by volume constraint","authors":"E. C. Bryant,&nbsp;N. A. Miller,&nbsp;K. C. Bennett","doi":"10.1007/s00161-024-01313-4","DOIUrl":"10.1007/s00161-024-01313-4","url":null,"abstract":"<div><p>Material modeling for micromorphic continua (in the sense of Eringen and Suhubi [IJES, 1964]) of combined viscoelastic-viscoplastic constitutive nonlinearity is developed, for application to some geomaterials and other granular materials, and is recast in a compact energetic formulation via “granular micromechanics.” Under the granular mechanics homogenization paradigm, potentials and pseudo-potentials for viscoelastic viscoplasticity are scale-bridged by averaging discrete grain-contact interactions over a representative granular assemblage. As a critical feature of the proposed multiscale method, higher-order kinematics are considerably simplified by employing a microstructural length scale in conjunction with Taylor-series expansion. In distinction to prior micromorphic micromechanics, our discrete-to-continuum scale-bridging embeds a volume constraint to weakly enforce mean-field definitions in the representative assemblage by the method of Lagrange multipliers: analogous to the classical three-field reformulation of a mixed interpolation space for nonlinear finite elements’ selective integration. As subsequently demonstrated, volume-constrained reformulation renders micromorphic modeling constitutively appropriate for viscoelastic viscoplastic particulate materials. As a consequence, coupled pressure- and rate-sensitive dissipative phenomena - i.e., of combined viscoelasticity and Drucker–Prager viscoplasticity– -become microstructurally sensitive and algorithmically advantageous, utilizing numerical methods in bound-constrained optimization.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1527 - 1551"},"PeriodicalIF":1.9,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141726069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of an initially stressed functionally graded thermoelastic medium (type III) without energy dissipation","authors":"Praveen Ailawalia,&nbsp;Anchal Sharma,&nbsp;Marin Marin,&nbsp;Andreas Öchsner","doi":"10.1007/s00161-024-01315-2","DOIUrl":"10.1007/s00161-024-01315-2","url":null,"abstract":"<div><p>The current investigation deals with the deformation of a non-homogeneous thermoelastic half space under hydrostatic initial stress for the Green–Naghdi model III. The medium is supposed to be rotating with a constant angular velocity. The non-homogeneous properties of the material are along the <i>x</i>-direction. At the first instance, the problem has been solved analytically to obtain stress and displacement components. Further, the numerical values of these expressions are evaluated using a computer program for a particular medium. The numerical values obtained are then presented graphically to show the effect of initial stress parameter and non-homogeneity parameter on the quantities.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1553 - 1564"},"PeriodicalIF":1.9,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-024-01315-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of extended irreversible thermodynamics and nonequilibrium statistical operator method with thermodynamics based on a distribution containing the first-passage time","authors":"V. V. Ryazanov","doi":"10.1007/s00161-024-01311-6","DOIUrl":"10.1007/s00161-024-01311-6","url":null,"abstract":"<div><p>An analogy is drawn between version of non-equilibrium thermodynamics a distribution-based containing an additional thermodynamic first-passage time parameter, nonequilibrium statistical operator method and extended irreversible thermodynamics with flows as an additional thermodynamic parameter. Thermodynamics containing an additional thermodynamic first-passage time parameter maps to extended irreversible thermodynamics. Various conditions for the dependence of the distribution parameters of the first-passage time on the random value of energy, the first thermodynamic parameter, are considered. Time parameter relaxation time <span>(tau )</span> of extended irreversible thermodynamics is replaced by the average first-passage time. Expressions are obtained for the thermodynamic parameter, the conjugate of the first passage time through the entropy change, and for the average first passage time through the flows.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1493 - 1513"},"PeriodicalIF":1.9,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00161-024-01311-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141597629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technological support for the durability of metal-cutting tools by the formation of wear-resistant coatings using energy-efficient methods","authors":"Yao Ju,&nbsp;Ievgen Konoplianchenko,&nbsp;Mykhailo Dumanchuk,&nbsp;Jiafei Pu,&nbsp;Qi Dong,&nbsp;Zhengchuan Zhang","doi":"10.1007/s00161-024-01312-5","DOIUrl":"10.1007/s00161-024-01312-5","url":null,"abstract":"<div><p>The purpose of this study was to evaluate the possibility of using mechanical spectroscopy to determine the strength of tool coatings from their lifespan. Mechanical spectroscopy with the determination of the index tan<span>(delta )</span> (internal friction) was used as the research method. Samples were coated with lamellae composed of WC-6wt% Co cemented carbides. The specimens measured 1.0 mm, 3.0 mm, and 40.0 mm, created using a conventional industrial liquid phase sintering procedure. The original powder consisted of cobalt with traces of chromium and vanadium, and submicron WC grains. The tools tested included carbide cutting tools, and the workpieces were steel alloys. Comparative results showed that coated tools had significantly improved tool life and durability. The relationship between the coating and tool life was evident, providing a practical approach for predictive and non-destructive analyses of coatings on tool durability for composite and finely structured materials.</p></div>","PeriodicalId":525,"journal":{"name":"Continuum Mechanics and Thermodynamics","volume":"36 6","pages":"1515 - 1525"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}