Search results for "Material parameter"

showing 5 items of 5 documents

Identification of circumferential regional heterogeneity of ascending thoracic aneurysmal aorta by biaxial mechanical testing

2019

Abstract Ascending thoracic aortic aneurysm (ATAA) in patients with bicuspid aortic valve (BAV) can present an asymmetrical aortic dilatation compared with patients with tricuspid aortic valve (TAV). This pattern of aneurysm dilatation led us to hypothesize that biomechanical differences likely induced by regional heterogeneity of material properties can underlie the observed asymmetric enlargement discrepancies between BAV ATAA and TAV ATAA. This study aimed to characterize the mechanical properties and associated aortic tissue stiffness changes along the circumferential direction of aortic rings collected from surgically-repaired patients with ATAA. Biaxial material testing was performed …

0301 basic medicineAortic valveMaleMaterial parameterBicuspid aortic valveHeart Valve DiseasesAorta Thoracic030204 cardiovascular system & hematologyThoracic aortic aneurysm03 medical and health sciences0302 clinical medicineBicuspid aortic valveAneurysmVascular StiffnessBicuspid Aortic Valve Diseasemedicine.arteryMedicineHumansIn patientMolecular BiologyAgedAged 80 and overAortaAortic Aneurysm Thoracicbusiness.industryAscending aortic aneurysmSettore ING-IND/34 - Bioingegneria IndustrialeAnatomyMiddle Agedmedicine.diseaseSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Tissue stiffness030104 developmental biologymedicine.anatomical_structureAortic Valvecardiovascular systemFemaleTissue stiffnessCardiology and Cardiovascular MedicinebusinessBiaxial testingSettore ICAR/08 - Scienza Delle CostruzioniElastic fiberDilatation Pathologic
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Partial data inverse problems for Maxwell equations via Carleman estimates

2015

In this article we consider an inverse boundary value problem for the time-harmonic Maxwell equations. We show that the electromagnetic material parameters are determined by boundary measurements where part of the boundary data is measured on a possibly very small set. This is an extension of earlier scalar results of Bukhgeim-Uhlmann and Kenig-Sj\"ostrand-Uhlmann to the Maxwell system. The main contribution is to show that the Carleman estimate approach to scalar partial data inverse problems introduced in those works can be carried over to the Maxwell system.

Inverse problemsELECTRODYNAMICSINFORMATIONadmissible manifoldsWEIGHTSMathematics::Analysis of PDEsBoundary (topology)InverseBOUNDARY-VALUE PROBLEMCALDERON PROBLEMpartial data01 natural sciencesMATERIAL PARAMETERSinversio-ongelmatsymbols.namesakeMathematics - Analysis of PDEsFOS: Mathematics35R30 35Q61111 MathematicsMaxwellin yhtälötBoundary value problemUniqueness0101 mathematicsPartial dataMathematical PhysicsMathematicsAdmissible manifoldsApplied Mathematicsta111010102 general mathematicsMathematical analysisScalar (physics)Inverse problemCarleman estimatesSmall set010101 applied mathematicsUNIQUENESSMaxwell's equationsMaxwell equationsLOCAL DATAsymbolsAnalysisAnalysis of PDEs (math.AP)
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NOVEL TOOLS FOR THE MECHANICAL ANALYSIS OF THIN PLATES AND RELEVANCE ON MEMBRANE-BASED TECHNOLOGIES

2020

Ion Exchange MembraneSettore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciProfiled MembraneFluid-Structure InteractionThin PlateMembraneMembrane DeformationReverse ElectrodialysiElectrodialysiMeshfree methodLine Element-Less MethodMaterial parameter identificationFluid redistribution.Settore ICAR/08 - Scienza Delle Costruzioni
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Analysis of Rectangular Orthotropic Membranes for Mechanical Properties Identification through Load-Displacement Data

2021

In this paper, an innovative procedure is introduced for the identification of the mechanical properties of orthotropic membranes based on load-displacement data. To this end, novel functional forms of the displacement components for rectangular membranes are appropriately introduced. Unknown coefficients of these displacement functions are determined, minimizing the total potential energy of the membrane. The energy method is then combined with an optimization procedure to estimate the elastic constants of the membranes in a straightforward manner. Specifically, a genetic algorithm is used to minimize a properly defined objective function directly related to the sought mechanical propertie…

Materials sciencebusiness.industryMechanical Engineering02 engineering and technologyStructural engineering021001 nanoscience & nanotechnologyOrthotropic materialBulge test Genetic algorithm Material parameter identification Membrane Orthotropic material Static responseIdentification (information)020303 mechanical engineering & transportsMembrane0203 mechanical engineeringMechanics of MaterialsBulge testGenetic algorithmStatic responseLoad displacement0210 nano-technologybusinessSettore ICAR/08 - Scienza Delle Costruzioni
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Vibration-based identification of mechanical properties of orthotropic arbitrarily shaped plates: Numerical and experimental assessment

2018

Abstract An innovative procedure is introduced for the identification of the mechanical parameters of orthotropic plates of arbitrary shape, under various boundary conditions, based on vibration data. The method employs a combination of a convenient Rayleigh-Ritz approach and Particle-Swarm Optimization to estimate elastic constants of the orthotropic material in a straightforward manner, without requiring computationally demanding iterative Finite Element analyses. Specifically, the pb-2 Rayleigh-Ritz procedure is extended and applied to deal with orthotropic plates, simplifying the approach to more easily treat generic plate shapes, taking advantage of the Green's theorem. The method is t…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciMaterials sciencePb-2 Rayleigh-Ritz approachContext (language use)Ceramics and Composite02 engineering and technologyOrthotropic materialIndustrial and Manufacturing Engineering0203 mechanical engineeringVibration testMaterial parameter identificationMechanics of MaterialBoundary value problemParticle-swarm optimizationComposite materialReliability (statistics)business.industryExperimental analysiMechanical EngineeringParticle swarm optimizationExperimental dataStructural engineering021001 nanoscience & nanotechnologyFinite element methodVibration020303 mechanical engineering & transportsMechanics of MaterialsCeramics and Composites0210 nano-technologybusinessSettore ICAR/08 - Scienza Delle Costruzioni
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