1,721,066 research outputs found
Modelling Junctions of Thin Plates
No full textThe paper deals with the modelling of junctions between plates. The junction is modelled as a structure in itself (a joint); it
is required that both the displacement and the traction fields be continuous at the common boundaries between the joint and the
plates. This modelling accounts for different plate models so as for deformable and rigid joint
Dynamical Interaction Between Local and Overall Curving in Circular Cylindrical Shells: A One-Dimensional Approach
No full textThe dynamic behaviour of a circular cylindrical shell is described by a one-dimensional model of
continuum with affine local structure. It is shown that, under suitable hypotheses on constitutive prescriptions,
the coupling among flexure of the axis due to an external forcing and the ovalisation of the cross-sections can be
reproduced. This dynamical interaction between global and local motions is investigated for a slender and simply
supported cylinder subject to a motion of the supports, near external and internal primary resonance conditions
Morphing of soft tubes by anisotropic growth
No full textWe present a study of smart growth in layered cylindrical structures. We start from the characterization of a compatible growth field in an anisotropic growing tube with the aim to show a small perturbation in the compatible growth field that may produce a controlled deprivation of compatibility and localization of elastic energy storage in a composite structure made up of anisotropic growing tubes
Models for striated muscles
No full textWe describe some known aspects of the mechanics of activated muscles
using a model for materials susceptible of remodeling. We present some
results on the mechanics and the energetics associated to different muscular
exercises as isotonic and isometric contractions. Moreover, we discuss
the modeling of some typical memory dependent phenomena such as force
enhancement/depression following stretching/shortening
Adaptive Remodelling of Arterial Walls
No full textWe present some results concerning the modelling of growth phenomena in an artery section.
In particular, we focus the attention on the role of the outer accretive forces, describing the
mechanical feedback from the biochemical control system, in the remodelling process. We view
such forces as the control parameters of the evolution of the relaxed state of the body and
prescribe them constitutively in such a way that the evolution process tend to a well-dened
limit (the so-called homeostatic conguration of the body
Torque-induced reorientation in active fibre-reinforced materials
No full textWe introduce a continuum model for a fibre reinforced material in which the reference orientation of the fibre may evolve with time, under the influence of external stimuli. The model is formulated in the framework of large strain hyperelasticity and the kinematics of the continuum is described by both a position vector and by a remodelling tensor which, in the present context, is an orthogonal tensor representing the fibre reorientation process. By imposing suitable thermodynamical restrictions on the constitutive equation, we obtain an evolution equation of the remodelling tensor governed by the Eshelby torque, whose stationary solutions are studied in absence of any external source terms. It is shown that the fibres reorient themselves in a configuration that minimises the elastic energy and get aligned along a direction that may or may not be of principal strain. The explicit analysis of the Hessian of the strain energy density allows us to discriminate among the stationary solutions, which ones are stable. Examples are given for passive reorientation processes driven by applied strains or external boundary tractions. Applications of the proposed theory to biological tissues, nematic or magneto-electro active elastomers are foreseen
Biomechanical Growth Laws for Arterial Walls
No full textWe present some results concerning the remodeling of arterial vessels
having a capacity for adaptation in response to biomechanical stimuli. In
particular, we focus the attention on the mechanical feedback from the biochemical
control system described by outer accretive forces, and on the role
of these forces in driving the remodeling phenomena that compensate modifications
of blood flow or ageing processes
THE INFLUENCE OF INITIAL STRESSES ON BLOOD VESSEL MECHANICS
No full textIn order to account for the in vivo conditions of blood vessels, we investigate the mechanical behavior of a stressed tube-like membrane when small deformations are superimposed on large deformations: the latter simulate the stretches present in the in vivo arteries while the superimposed deformations account for the small - but essential for the blood propagation - deformations due to the pulsatile nature of the blood flow. Our aim is to discuss how a stress state influence the response of the vessel-blood system
- …
