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Showing 1 to 20 of 67 for “"Constitutive law"”.
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Recovering elastic moduli of nonlinear anisotropic annular membranes from interior measurements of deformation and pressure
… The model makes no specification of the constitutive law by which stresses are calculated from applied strains. Under appropriate choice of the constitutive law and simplification of the geometry, we show that membranes of regular structure may be homogenized to an axisymmetric case. We …
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Atomistic Study of Grain Boundary Sliding
… several open questions like an appropriate GBS constitutive law and determination of the threshold stress for sliding. Molecular Dynamics (MD) simulation performed by Qi and Krajewski establish a linear fit to the constitutive response which gives a sliding velocity of the order of km/sec. Their …
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Modeling and Analysis of Cyclic Behavior of Sands
… loading. The model, to qualify as an acceptable constitutive law for cyclic behavior of sands, should be able to represent the following aspects of behavior: (a) Hysteretic energy dissipation; (b) Accumulated irreversible deformation; (c) Volumetric deformations.
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Variational formulations and numerical analysis of some problems in small strain elastoplasticity
… is based on a consistent incremental holonomic constitutive law, which in turn derives from the notion of extremal paths in stress and strain space as originally proposed by PONTER & MARTIN (1972); the second problem which we study is the classical rate problem. We show that both problems can be …
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The Creep Behaviour of Rubbers Reinforced with Particulate or Short Fibres
… be captured well by using the Miller-Norton constitutive law and the observed dependence on temperature has been used to estimate the activation energy for creep to be ~ 7 kJ mole-1. This showed that the creep process did not involve rupture of covalent bonds (for the range of applied loads …
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Hysteresis modeling of wood joints and structural systems
… (BWBN) model. The hysteretic constitutive law, based on the endochronic theory of plasticity and characterized by a single mathematical form, produces a versatile, smoothly varying hysteresis that models previously observed behavior of wood joints and structural systems, …
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ΥΠΟΛΟΓΙΣΜΟΣ ΦΟΡΕΩΝ ΓΙΑ ΠΛΗΡΕΙΣ ΝΟΜΟΥΣ ΤΩΝ ΔΟΜΙΚΩΝ ΤΟΥΣ ΣΤΟΙΧΕΙΩΝ
… BEHAVIOUR ARE STUDIED. THE NOTION OF "COMPLETE" CONSTITUTIVE LAW IN MECHANICS IS FIRST INTRODUCED. THE MATHEMATICAL MODEL OF THE STATIC AND DYNAMIC PROBLEM OF STRUCTURES WITH COMPLETE CONSTITUTIVE LAWS OF THEIR ELEMENTS IS NEXT FORMULATED IN THE FORM OF HEMIVARIATIONAL INEQUALITY AND …
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ΜΟΝΤΕΛΟ ΠΕΠΕΡΑΣΜΕΝΩΝ ΣΤΟΙΧΕΙΩΝ ΓΙΑ ΤΗΝ ΑΝΑΛΥΣΗ ΔΙΣΚΩΝ ΟΠΛΙΣΜΕΝΟΥ ΣΚΥΡΟΔΕΜΑΤΟΣ ΥΠΟ ΜΟΝΟΤΟΝΗ ΚΑΤΑΠΟΝΗΣΗ ΜΕΧΡΙΣ ΑΣΤΟΧΙΑΣ
… INCLUDES ORIGINAL BIAXIAL NONLINEAR ISOTROPIC CONSTITUTIVE LAW FOR THE UNCRACKED CONCRETE, ORTHOTROPIC FOR THE CRACKED CONCRETE AND NONLINEAR RELATION BETWEEN BOND STRESSES AND THE RELATIVE (CONCRETE-STEEL) SLIP. THE MODEL IS CAPABLE OF REPRESENTING THE VARIOUS TYPES OF LOCAL DAMAGES OF …
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A finite element analysis of adhesively bonded composite joints including geometric nonlinearity, nonlinear viscoelasticity, moisture diffusion and delayed failure
… using Schapery's nonlinear single integral constitutive law for uniaxial and multiaxial states of stress. Effect of temperature and stress level on the viscoelastic response is taken into account by a nonlinear shift factor definition. Penetrant sorption is accounted for by a nonlinear …
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Modeling cycle and time dependent creep/relaxation effects on fatigue lives of notched members
… response was modeled using viscoplasticity constitutive laws and Neuber’s rule eliminating the need for finite element modeling of uniaxially loaded notched members. However, the Nenber’s modeling may be used with any material constitutive law. The procedures for fatigue damage used cycle …
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Mechanisms of Ductile Fracture: Void Growth by Dislocation -Loop Emission and Hydrogen-Assisted Crack Propagation
… was considered to establish the material constitutive law. Simulations in a unit cell containing a void were carried out to devise traction-separation laws reflecting the hydrogen effect on void growth and coalescence over a range of stress triaxialities representative of the material …
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Stochastic finite element analyses of uncertain nonlinear plane trusses under random excitations
… large deflection and inelastic deformation. The constitutive law is based on an explicit differential equation model, and the model parameters are determined in terms of material property constants according to plasticity theory. Random excitations are modeled as Gaussian filtered white noises, …
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MACHINE LEARNING FOR CONSTITUTIVE MODELLING
… cost. These surrogate models provide the constitutive law of the micro scale simulations after a training process, called off-line learning. For history dependent materials, the recurrent neural network (RNN) is adopted for the training of path dependent mechanical responses, due to its …
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Nonlinear ultrasonic guided waves for quantitative life prediction of structures with complex geometries
… modified to take into account a different constitutive law. Also the boundary conditions need to be reviewed to ensure free stress with the non-linear behavior. The propagation of the longitudinal wave is investigated in detail. Numerical accuracy is validated from comparison with a closed, …
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Stochastic dynamic response of wood structural systems
… (BWBN) model. The hysteretic constitutive law, based on the endochronic theory of plastidty and characterized by a single mathematical form, produces a versatile, smoothly varying hysteresis that models previously observed behavior of wood joints and structural systems, namely, …
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Multiscale Computational Framework for Analysis and Design of Ultra-High Performance Concrete Structural Components and Systems
… extends a structural-level triaxial continuum constitutive law to account for the addition of discrete fibers. The approach is robust, general, and could be utilized by other researchers to expand the computational capability and simulate the behavior of different composite materials. The work …
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A hybrid finite element procedure for soil-structure interaction including construction sequences
… analysis, the Drucker-Prager model is used as a constitutive law. In order to verify the computer program and to examine the accuracy of the hybrid stress model, several problems such as a beam, a plate with circular hole, and footings are analyzed, and the results are compared with those from …
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Analysis of soil penetrometer using Eulerian finite element method
… requires special procedures to convect the soil constitutive law and prevent numerical diffusion. The current analyses use the program DiekA, developed at the University of Twente in the Netherlands. Detailed calculations have been performed to investigate the effects of elements size and …
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Testing and inverse modelling for solder joint reliability assessment
… technique and experimental data to obtain constitutive laws for lead-free solder alloys. In the development of the vibration test machine, a prototype test machine that uses piezoelectric cell as actuators for the loading was modelled using the Finite Element Analysis method, and the …
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Piezoelectric active sensor and electric impedance approach for structural dynamic measurement
… model is derived based on the one-dimensional constitutive law of the PZT and the mechanical impedance approach. The model yields explicit expressions of structural mechanical mobility in terms of the measured electric admittance. Applications of the approach in smart structures are presented …
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