Applications in engineering science最新文献

{"title":"Innovalve transcatheter mitral valve replacement system: Short-term pre-clinical study in pigs","authors":"Avi Avner ,&nbsp;Nicolas Borenstein ,&nbsp;Boris Orlov ,&nbsp;Ehud Raanani","doi":"10.1016/j.apples.2023.100144","DOIUrl":"10.1016/j.apples.2023.100144","url":null,"abstract":"<div><p>Innovalve is a transcatheter mitral valve replacement (TMVR) system with a unique fixation system that aims to grasp the chordae in a rotational maneuver.</p></div><div><h3>Objectives</h3><p>This study will examine the safety and efficacy of the transapical mitral implantation of Innovalve bioprosthesis in the porcine model.</p></div><div><h3>Methods</h3><p>Innovalve MV bioprosthesis was implanted in the porcine model (5 pigs) for a duration of 30 days.</p></div><div><h3>Results</h3><p>The Innovalve bioprosthesis was successfully implanted in all of the animals with accurate positioning, anchoring and good paravalvular sealing. At 30 days after implantation, all animals exhibited normal clinical status without evidence of cardiac impairment. The prosthetic valve seemed adequately adhered to the mitral annulus with fibrous tissue.</p></div><div><h3>Conclusion</h3><p>We have demonstrated that the implantation of the Innovalve in healthy porcine subjects is feasible and safe and that the valve function and interaction with normal biological tissue is favorable and predictable.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"15 ","pages":"Article 100144"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46190990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On flow of power-law fluids between adjacent surfaces: Why is it possible to derive a Reynolds-type equation for pressure-driven flow, but not for shear-driven flow?","authors":"Andreas Almqvist ,&nbsp;Evgeniya Burtseva ,&nbsp;Kumbakonam Rajagopal ,&nbsp;Peter Wall","doi":"10.1016/j.apples.2023.100145","DOIUrl":"10.1016/j.apples.2023.100145","url":null,"abstract":"<div><p>Flows of incompressible Navier–Stokes (Newtonian) fluids between adjacent surfaces are encountered in numerous practical applications, such as seal leakage and bearing lubrication. In seals, the flow is primarily pressure-driven, whereas, in bearings, the dominating driving force is due to shear. The governing Navier–Stokes system of equations can be significantly simplified due to the small distance between the surfaces compared to their size. From the simplified system, it is possible to derive a single lower-dimensional equation, known as the Reynolds equation, which describes the pressure field. Once the pressure field is computed, it can be used to determine the velocity field. This computational algorithm is much simpler to implement than a direct numerical solution of the Navier–Stokes equations and is therefore widely employed by engineers. The primary objective of this article is to investigate the possibility of deriving a type of Reynolds equation also for non-Newtonian fluids, using the balance of linear momentum. By considering power-law fluids we demonstrate that it is not possible for shear-driven flows, whereas it is feasible for pressure-driven flows. Additionally, we demonstrate that in the full <span><math><mrow><mn>3</mn><mi>D</mi></mrow></math></span> model, a normal stress boundary condition at the inlet/outlet implies a Dirichlet condition for the pressure in the Reynolds equation associated with pressure-driven flow. Furthermore, we establish that a Dirichlet condition for the velocity at the inlet/outlet in the <span><math><mrow><mn>3</mn><mi>D</mi></mrow></math></span> model results in a Neumann condition for the pressure in the Reynolds equation.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"15 ","pages":"Article 100145"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46482956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of microscopic residual stresses using genetic programming","authors":"Laura Millán ,&nbsp;Gabriel Kronberger ,&nbsp;Ricardo Fernández ,&nbsp;Gizo Bokuchava ,&nbsp;Patrice Halodova ,&nbsp;Alberto Sáez-Maderuelo ,&nbsp;Gaspar González-Doncel ,&nbsp;J. Ignacio Hidalgo","doi":"10.1016/j.apples.2023.100141","DOIUrl":"https://doi.org/10.1016/j.apples.2023.100141","url":null,"abstract":"<div><p>Metallurgical manufacturing processes commonly used in the industry (rolling, extrusion, shaping, machining, etc.) usually cause residual stress development which can remain after thermal heat treatments. These stresses can be detrimental for the in-service performance of structural components, which makes their study and understanding important. Residual stress variations are usually determined at a macroscopic scale (commonly, using diffraction methods). However, stress variations at the microscopic scale of the individual crystallites (grains), are also relevant. Contrary to the macroscopic residual stresses, microscopic residual stresses are difficult to quantify using conventional procedures. We propose to use machine learning to find equations that describe microscopic residual stresses. Concretely, we show that we are able to learn equations to reproduce the diffraction profiles from microstructural characteristics using genetic programming. We evaluate the learned equations using real neutron diffraction peaks as a reference, obtaining accurate results for the most frequent grain orientations with runtimes of a few minutes.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"15 ","pages":"Article 100141"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50182919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planar phonon anisotropy, and a way to detect local equilibrium temperature in graphene","authors":"Marco Coco","doi":"10.1016/j.apples.2023.100135","DOIUrl":"10.1016/j.apples.2023.100135","url":null,"abstract":"<div><p>The effect of inclusion of the planar phonon anisotropy on thermo-electrical behavior of graphene is analyzed. Charge transport is simulated by means of Direct Simulation Monte Carlo technique coupled with numerical solution of the phonon Boltzmann equations based on deterministic methods.</p><p>The definition of the crystal lattice local equilibrium temperature is investigated as well and the results furnish possible alternative approaches to identify it starting from measurements of electric current density, with relevant experimental advantages, which could help to overcome the present difficulties regarding thermal investigation of graphene.</p><p>Positive implications are expected for many applications, as the field of electronic devices, which needs a coherent tool for simulation of charge and hot phonon transport; the correct definition of the local equilibrium temperature is in turn fundamental for the study, design and prototyping of cooling mechanisms for graphene-based devices.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"15 ","pages":"Article 100135"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45600489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hindered thermal warping triggers tensile cracking in the cores of compressed columns of a fire-loaded tunnel segment structure: Efficiency and accuracy of beam theory prediction, compared to FEM","authors":"Maximilian Sorgner ,&nbsp;Rodrigo Díaz Flores ,&nbsp;Hui Wang ,&nbsp;Christian Hellmich ,&nbsp;Bernhard L.A. Pichler","doi":"10.1016/j.apples.2023.100128","DOIUrl":"10.1016/j.apples.2023.100128","url":null,"abstract":"<div><p>The nonlinear Finite Element Method (FEM) is the current gold standard for the thermo-mechanical analysis of reinforced concrete structures. As an alternative, this paper is devoted to a model reduction strategy which reduces the CPU time by a factor of 500. This strategy combines Fourier series-based solutions for the thermal conduction problem, and thermo-elastic Timoshenko beam theory. Temperature histories known to be relevant for fire accidents enter series solutions quantifying the conduction of heat into a closed cell frame consisting of slabs, walls, and columns. Corresponding temperature profiles are translated into thermal eigenstrains. The latter are represented as the sum of three portions: (i) their cross-sectional averages (called thermal eigenstretches); (ii) their cross-sectional moments (called thermal eigencurvatures); and (iii) the remaining eigenstrain distributions (called eigenwarping). The latter portion is hindered at the cross-sectional scale, giving rise to non-linearly distributed self-equilibrated thermal stresses. The eigenstretches and eigencurvatures, in turn, are constrained at the scale of the frame structure. Together with external mechanical loads, they enter the exact solutions of thermo-elastic Timoshenko beam theory with equivalent cross-sections accounting for the different material properties of concrete and steel. Axial normal stresses, quantified from beam-theory-related normal forces and bending moments, are superimposed with the hindered-warping-induced stresses. These stresses agree well with corresponding results obtained by the nonlinear FEM. As regards the load carrying behavior of the columns, excessive thermal tensile strains at the periphery of the columns trigger, in the core of the columns, large tensile stresses which even exceed the strength of concrete. Respective cracking events are considered through reduced effective columnar cross-sections. Right after initiation of cracking, around 12<!--> <!-->min after the start of the heating process, the cracks propagate for some 30<!--> <!-->sec quite rapidly, and very much slower thereafter. If the initial cross-sections of the columns are increased, more pronounced hindered thermal warping, together with less quickly evolving compressive forces, results in earlier cracking. Overall, it is concluded that tensile cracking is the key material non-linearity, at least during the first 30<!--> <!-->min of the fire test, with maximum temperatures up to 300<!--> <!-->°C.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"14 ","pages":"Article 100128"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48256854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive mesh refinement for the phase field method: A FEniCS implementation","authors":"F. Freddi,&nbsp;L. Mingazzi","doi":"10.1016/j.apples.2023.100127","DOIUrl":"10.1016/j.apples.2023.100127","url":null,"abstract":"<div><p>This paper reports insightful implementation details of the global adaptive refinement procedure for the phase-field method recently published in Freddi and Mingazzi (2022). Phase field approaches reproduce cracks within solids in a smeared manner. The small transition zone between broken and unbroken material, whose width is controlled by an internal scale length parameter, permits to precisely replicate complex sharp crack topologies only if an extremely fine mesh is adopted. Starting from a coarse mesh, the proposed refinement process utilizes an energetic criterion to selectively refine the elements on which cracks may propagate. In fully broken areas, where the phase field is no longer evolving, a specific refinement is adopted to capture the high displacement gradient. The implementation is performed within the open-source finite element software FEniCS (ver. 19.1.0) which provides a framework for automated solutions of partial differential equations. The fundamental aspects of the code are described starting from the functional definition to the various steps of the refinement technique. A representative example is illustrated to supply further information on the code functionality. The code can be downloaded from <span>https://github.com/LorenzoMingazzi/AGu-AGal</span><svg><path></path></svg> and be used to easily apply the proposed refinement strategy to different problems or as a starting point for more sophisticated formulations.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"14 ","pages":"Article 100127"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44011082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical response of elastic materials with density dependent Young modulus","authors":"Vít Průša,&nbsp;Ladislav Trnka","doi":"10.1016/j.apples.2023.100126","DOIUrl":"10.1016/j.apples.2023.100126","url":null,"abstract":"<div><p>The experimental as well as theoretical engineering literature on porous structures such as metal foams, aerogels or bones often relies on the standard linearised elasticity theory, and, simultaneously, it frequently introduces the concept of “density dependent Young modulus”. We interpret the concept of “density dependent Young modulus” literally, that is we consider the linearised elasticity theory with the generalised Young modulus being a function of the current density, and we briefly summarise the existing literature on theoretical justification of such models. Subsequently we numerically study the response of elastic materials with the “density dependent Young modulus” in several complex geometrical settings.</p><p>In particular, we study the extension of a right circular cylinder, the deflection of a thin plate, the bending of a beam, and the compression of a cube subject to a surface load, and we quantify the impact of the density dependent Young modulus on the mechanical response in the given setting. In some geometrical settings the impact is almost nonexisting—the results based on the classical theory with the constant Young modulus are nearly identical to the results obtained for the density dependent Young modulus. However, in some cases such as the deflection of a thin plate, the results obtained with constant/density dependent Young modulus differ considerably despite the fact that in both cases the infinitesimal strain condition is well satisfied.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"14 ","pages":"Article 100126"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42650738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations on design limits and improved material utilization of press-fit connections using elastic-plastic design","authors":"Jan Falter,&nbsp;Hansgeorg Binz ,&nbsp;Matthias Kreimeyer","doi":"10.1016/j.apples.2022.100124","DOIUrl":"10.1016/j.apples.2022.100124","url":null,"abstract":"<div><p>Today, there are a number of analytical and numerical calculation methods for the elastic-plastic design of press-fit connections. However, these are largely constrained by their restriction to elastic-ideal-plastic material behavior. In addition, recommendations for limiting the plasticized hub cross section that have been provided to date do not exploit the full potential of the materials, with the result that opportunities for lightweight design and improved transmission capacity have remained unused so far. Yet, no experimental validations exist to this end, which is why the existing design method could not be validated until today. In addition, there is still a lack of research on how to evaluate the potential for increasing the force and torque transmission under consideration of the strain hardening of the material during plastic deformation. The lack of knowledge today prevents a targeted design and thereby the industrial application of this type of connection; the transmission capacity and lightweight design potentials have thus remained unused until now (<span>Kröger and Binz, 2020</span>). This article presents the actual design and joining limits of hubs made of EN AW-5083 (AlMg4,5Mn), which were determined as part of an Industrial Collective Research (IGF) project. This allows the hub materials to be better utilized, which leads to a reduction in mass and/or an increase in the force and torque transmission. In addition, the experimental validation of the numerical investigations helps to establish the design method in industrial practice.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"13 ","pages":"Article 100124"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45413793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-field formulations for solving plane problems involving viscoelastic constitutive relations","authors":"S. Ananthapadmanabhan,&nbsp;U. Saravanan","doi":"10.1016/j.apples.2022.100120","DOIUrl":"10.1016/j.apples.2022.100120","url":null,"abstract":"<div><p>This article reports a multi-field numerical formulation for solving plane problems involving viscoelastic materials. Stress fields satisfying equilibrium equations are constructed using Airy’s potentials which are expressed as a linear combination of <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> basis functions. The strain field is derived from a continuous displacement field obtained from a linear combination of <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>0</mn></mrow></msup></math></span> basis functions. An appropriate linear combination of these stress and displacement basis functions is determined such that the resulting stress and strain fields satisfy the constitutive relation subjected to the satisfaction of the constraints arising from the boundary conditions. Since a viscoelastic constitutive relation involves stress, strain, and their rates, stress and displacement degrees of freedom or their rates can be considered as optimization variables for minimizing the error in satisfying the constitutive relation. Two Algorithms are proposed based on this choice of optimization variable. Accuracy and efficiency of the proposed algorithms are studied through five different boundary value problems involving four forms of the viscoelastic constitutive relations and for two loading histories. Using the developed rectangular element, viscoelastic beam bending problem is solved for the different constitutive relations studied.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"13 ","pages":"Article 100120"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47830854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical modelling and parameter classification enable understanding of dynamic shape-change issues adversely affecting high energy-density battery metal anodes","authors":"Benedetto Bozzini ,&nbsp;Elisa Emanuele ,&nbsp;Jacopo Strada ,&nbsp;Ivonne Sgura","doi":"10.1016/j.apples.2022.100125","DOIUrl":"10.1016/j.apples.2022.100125","url":null,"abstract":"<div><p>Owing to the difficulty of studying materials in real-life battery context, research on metal anodes, suffers from a methodological gap between materials- and device-orientated studies. This gap can be bridged by quantitatively linking the electrical response of the device to the evolution of the material inside the cell. The capability of establishing this link, on the one hand, allows to frame the correct space- and time-scales that are relevant to device research and, on the other hand, helps pinpoint the global observables that can be associated with molecular-level information and imaging. This study contributes to the construction of a conceptual platform, that will enable to rationalize the electrical response of the device on the basis of materials-relevant quantities. To this aim: (i) we have developed a PDE-based mathematical model for the response of a single symmetric cell with metal electrodes; (ii) we have validated it with high-quality data from Zn/Zn symmetric coin-cell cycling in weakly acidic alkaline aqueous electrolyte, containing quaternary ammonium additives, and (iii) we have carried out a parameter-classification task for the experimental data, that notably extended the physico-chemical insight into the mechanism of action of anode-stabilizing additives.</p></div>","PeriodicalId":72251,"journal":{"name":"Applications in engineering science","volume":"13 ","pages":"Article 100125"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44051856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}