399 research outputs found
Finite elastic deformations of transversely isotropic circular cylindrical tubes
We consider the finite radially symmetric deformation of a circular cylindrical tube of a homogeneous transversely isotropic elastic material subject to axial stretch, radial deformation and torsion, supported by axial load, internal pressure and end moment. Two different directions of transverse isotropy are considered: the radial direction and an arbitrary direction in planes normal locally to the radial direction, the only directions for which the considered deformation is admissible in general. In the absence of body forces, formulas are obtained for the internal pressure, and the resultant axial load and torsional moment on the ends of the tube in respect of a general strain-energy function. For a specific material model of transversely isotropic elasticity, and material and geometrical parameters, numerical results are used to illustrate the dependence of the pressure, (reduced) axial load and moment on the radial stretch and a measure of the torsional deformation for a fixed value of the axial stretch
The exponentiated Hencky-logarithmic strain energy. Part I: Constitutive issues and rank-one convexity
We investigate a family of isotropic volumetric-isochoric decoupled strain
energies based on the Hencky-logarithmic (true, natural)
strain tensor , where is the infinitesimal shear modulus,
is the infinitesimal bulk modulus with
the first Lam\'{e} constant, are dimensionless
parameters, is the gradient of deformation,
is the right stretch tensor and is the deviatoric part of the strain tensor . For small elastic strains, approximates the classical
quadratic Hencky strain energy which is not everywhere
rank-one convex. In plane elastostatics, i.e. , we prove the everywhere
rank-one convexity of the proposed family , for and . Moreover, we show that the
corresponding Cauchy (true)-stress-true-strain relation is invertible for
and we show the monotonicity of the Cauchy (true) stress tensor as a
function of the true strain tensor in a domain of bounded distortions. We also
prove that the rank-one convexity of the energies belonging to the family
is not preserved in dimension
ICMM6
This volume contains selected papers presented at the 6th International Conference on Material Modeling (ICMM6), which took place June 26-28 2019 at the campus of Lund University, Sweden. By all meaningful measures, ICMM6 was a great success, attracting 161 participants from almost 30 countries (ranging from senior colleagues to graduate students)and featuring a technical program that well reflected the cutting-edge of materials modeling research.
ICMM6 included thematic sessions on the following topics
• linear elasticity and viscoelasticity
• nonlinear elasticity
• plasticity and viscoplasticity
• experimental identification and material characterization
• Cosserat, micromorphic and gradient materials
• atomistic/continuum transition on the nanoscale
• optimization and inverse problems in multiscale modeling
• granular materials and particle systems
• biomechanics and biomaterials
• electronic materials
• heterogeneous materials
• coupled field problems
• creep, damage and fatigue
• numerical aspects of material modeling.
The aim of the ICMM conferences is to bring together researchers from different fields of material modeling and material characterization, and to cover essentially all aspects of material modeling thus providing the opportunity for interactions between scientists working in different subareas of material mechanics who otherwise would not come into contact with each other
On 3-D inelastic analysis methods for hot section components (base program)
A 3-D Inelastic Analysis Method program is described. This program consists of a series of new computer codes embodying a progression of mathematical models (mechanics of materials, special finite element, boundary element) for streamlined analysis of: (1) combustor liners, (2) turbine blades, and (3) turbine vanes. These models address the effects of high temperatures and thermal/mechanical loadings on the local (stress/strain)and global (dynamics, buckling) structural behavior of the three selected components. Three computer codes, referred to as MOMM (Mechanics of Materials Model), MHOST (Marc-Hot Section Technology), and BEST (Boundary Element Stress Technology), have been developed and are briefly described in this report
ANN-aided incremental multiscale-remodelling-based finite strain poroelasticity
Mechanical modelling of poroelastic media under finite strain is usually
carried out via phenomenological models neglecting complex micro-macro scales
interdependency. One reason is that the mathematical two-scale analysis is only
straightforward assuming infinitesimal strain theory. Exploiting the potential
of ANNs for fast and reliable upscaling and localisation procedures, we propose
an incremental numerical approach that considers rearrangement of the cell
properties based on its current deformation, which leads to the remodelling of
the macroscopic model after each time increment. This computational framework
is valid for finite strain and large deformation problems while it ensures
infinitesimal strain increments within time steps. The full effects of the
interdependency between the properties and response of macro and micro scales
are considered for the first time providing more accurate predictive analysis
of fluid-saturated porous media which is studied via a numerical consolidation
example. Furthermore, the (nonlinear) deviation from Darcy's law is captured in
fluid filtration numerical analyses. Finally, the brain tissue mechanical
response under uniaxial cyclic test is simulated and studied
Void initiation in a class of compressible elastic materials
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaves 40-41.by Nazmiye Ertan Arnold.M.S
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