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Displaying 101 –
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The concept of reduced plastic dissipation is introduced for a perfectly plastic rate-independent material not obeyng the associated normality rule and characterized by a strictly convex plastic potential function. A maximum principle is provided and shown to play the role of variational statement for the nonassociative constitutive equations. The Kuhn-Tucker conditions of this principle describe the actual material behaviour as that of a (fictitious) composite material with two plastic constituents,...
In this paper we prove a maxmin principle for nonlinear nonoverdamped eigenvalue problems corresponding to the characterization of Courant, Fischer and Weyl for linear eigenproblems. We apply it to locate eigenvalues of a rational spectral problem in fluid-solid interaction.
Vasculogenesis and angiogenesis are two different mechanisms for blood vessel formation. Angiogenesis occurs when new vessels sprout from pre-existing vasculature in response to external chemical stimuli. Vasculogenesis occurs via the reorganization of randomly distributed cells into a blood vessel network. Experimental models of vasculogenesis have suggested that the cells exert traction forces onto the extracellular matrix and that these forces may play an important role in the network forming...
Vasculogenesis and angiogenesis are two different mechanisms for blood
vessel formation. Angiogenesis occurs when new vessels sprout from
pre-existing vasculature in response to external chemical stimuli.
Vasculogenesis occurs via the reorganization of randomly distributed
cells into a blood vessel network. Experimental models
of vasculogenesis have suggested that the cells exert traction forces
onto the extracellular matrix and that these forces may play
an important role in the network forming...
A Mimetic Discretization method for the linear elasticity problem
in mixed weakly symmetric form is developed. The scheme is shown to
converge linearly in the mesh size, independently of the
incompressibility parameter λ, provided the discrete scalar
product satisfies two given conditions. Finally, a family of
algebraic scalar products which respect the above conditions is
detailed.
In the context of the linear, dynamic problem for elastic bodies with voids, a minimum principle in terms of mechanical energy is stated. Involving a suitable (Reiss type) function in the minimizing functional, the minimum character achieved in the Laplace-transform domain is preserved when going back to the original time domain. Initial-boundary conditions of quite general type are considered.
A unilateral problem of an elastic plate above a rigid interior obstacle is solved on the basis of a mixed variational inequality formulation. Using the saddle point theory and the Herrmann-Johnson scheme for a simultaneous computation of deflections and moments, an iterative procedure is proposed, each step of which consists in a linear plate problem. The existence, uniqueness and some convergence analysis is presented.
A modal synthesis method to solve the elastoacoustic vibration problem is analyzed. A two-dimensional coupled fluid-solid system is considered; the solid is described by displacement variables, whereas displacement potential is used for the fluid. A particular modal synthesis leading to a symmetric eigenvalue problem is introduced. Finite element discretizations with lagrangian elements are considered for solving the uncoupled problems. Convergence for eigenvalues and eigenfunctions is proved, error...
A modal synthesis method to solve the elastoacoustic vibration problem
is analyzed. A two-dimensional coupled fluid-solid system is considered;
the solid is described by displacement variables, whereas displacement
potential is used for the fluid. A particular modal synthesis leading to
a symmetric eigenvalue problem is introduced. Finite element discretizations
with Lagrangian elements are considered for solving the uncoupled problems.
Convergence for eigenvalues and eigenfunctions is proved,...
This paper deals with modeling the passive
behavior of skeletal muscle tissue including
certain microvibrations at the cell level. Our
approach combines a continuum mechanics model
with large deformation and incompressibility at
the macroscale with chains of coupled
nonlinear oscillators.
The model verifies that an externally applied
vibration at the appropriate frequency is able to synchronize
microvibrations in skeletal muscle cells.
From the numerical analysis point of view,
one faces...
The influence of a seismic wave on a building is customarily described as a force, a function of the time, whose explicit expression is prescribed. We here suggest a one-dimensional model able to relate this force to the sudden onset of a fault in the rock layer on which the building is built.
We consider a model problem (with constant coefficients and simplified
geometry) for the boundary layer phenomena which appear in thin shell theory
as the relative thickness ε of the shell tends to
zero. For ε = 0 our problem is parabolic, then it is a
model of developpable surfaces. Boundary layers along and across the characteristic
have very different structure. It also appears internal layers associated
with propagations of singularities along the characteristics. The special
structure of...
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