Geometrically exact Cosserat rods with Kelvin–Voigt type viscous damping

We present the derivation of a simple viscous damping model of Kelvin–Voigt type for geometrically exact Cosserat rods from three-dimensional continuum theory. Assuming moderate curvature of the rod in its reference configuration, strains remaining small in its deformed configurations, strain rates that vary slowly compared to internal relaxation processes, and a homogeneous and isotropic material, we obtain explicit formulas for the damping parameters of the model in terms of the well known stiffness parameters of the rod and the retardation time constants defined as the ratios of bulk and shear viscosities to the respective elastic moduli. We briefly discuss the range of validity of the Kelvin–Voigt model and illustrate its behaviour for large bending deformations with a numerical example

Experience in Organizing Training in Neuropsychology in a Distance Format (Based on the Materials of the II Luria International Summer School)

В 2020 г. МГУ им. М. В. Ломоносова и УрФУ им. первого Президента России Б. Н. Ельцина провели II Летнюю международную школу имени А. Р. Лурии при поддержке РФФИ. В нем приняли участие 13 экспертов мирового уровня и 246 слушателей из 47 стран. Данная статья представляет собой итоговый отчет по тематическим направлениям работы Школы.In 2020, Lomonosov State University and UrFU named after the first President of Russia B. N. Yeltsin held the II Summer International School named after A. R. Luriasupported by the RFBR. 13 world experts and 246 listeners from 47 countries took part in the event. This article is a final report on the thematic areas of the School’s work

Construction of discrete shell models by geometric finite differences

In the presented work, we make use of the strong reciprocity between kinematics and geometry to build a geometrically nonlinear, shearable low order discrete shell model of Cosserat type defined on triangular meshes, from which we deduce a rotation–free Kirchhoff type model with the triangle vertex positions as degrees of freedom. Both models behave physically plausible already on very coarse meshes, and show good convergence properties on regular meshes. Moreover, from the theoretical side, this deduction provides a common geometric framework for several existing models

Geometrically exact Cosserat rods with Kelvin-Voigt type viscous damping

We present the derivation of a simple viscous damping model of Kelvin–Voigt type for geometrically exact Cosserat rods from three–dimensional continuum theory. Assuming a homogeneous and isotropic material, we obtain explicit formulas for the damping parameters of the model in terms of the well known stiffness parameters of the rod and the retardation time constants defined as the ratios of bulk and shear viscosities to the respective elastic moduli. We briefly discuss the range of validity of our damping model and illustrate its behaviour with a numerical example

Construction of discrete shell models by geometric finite differences

In the presented work, we make use of the strong reciprocity between kinematics and geometry to build a geometrically nonlinear, shearable low order discrete shell model of Cosserat type defined on triangular meshes, from which we deduce a rotation–free Kirchhoff type model with the triangle vertex positions as degrees of freedom. Both models behave physically plausible already on very coarse meshes, and show good convergence properties on regular meshes. Moreover, from the theoretical side, this deduction provides a common geometric framework for several existing models