DYNAMICAL VISCO-ELASTIC CONSTANTS AND POISSON'S RATIO OF CONCRETE

Mathematical analysis of thermo-visco-elastic models

Motywacją do badań nad równaniami opisującymi odkształcenia termo-lepko-sprężyste jest potrzeba lepszego opisu procesów zachodzących w różnych materiałach oraz zbudowania lepszych modeli ich zachowania pod wpływem działania sił zewnętrznych. Wraz z rozwojem techniki zdobywamy głębszą wiedzę na temat różnych tworzyw. Pozwala nam to na tworzenie coraz bardziej poprawnych modeli opisujących zachow...

Homogenization of nonlinear visco-elastic composites

Quasi-static processes in nonlinear visco-elastic materials of solid-type are here represented by the system: σ −B(x) : ∂ε ∂t ∈ β(ε, x), −divσ = f , (∗) coupled with initial and boundary conditions. Here σ denotes the stress tensor, ε the linearized strain tensor, B(x) the viscosity tensor, β(·, x) a (possibly multi-valued) maximal monotone mapping, and f an applied load. Existence and uniquene...

Determination of nonlinear elastic constants and stress monitoring in concrete by coda waves analysis

For non destructive stress evaluation in prestressed concrete, we describe in this paper a promising ultrasonic method. In "ordinary" isotropic homogeneous materials such as steel, ultrasonic determination of third order elastic constants provides means for stress evaluation since half a century. Acoustoelasticity is aimed at measuring ultrasonic velocity changes at progressively increasing app...

2 A Computational Model for Visco - Elastic

Particle diiusion in rotating drums is studied via computer simulations using a full 3-D model which does not involve any arbitrary input parameters. The diiusion coeecient for single-component systems agree qualitatively with previous experimental results. On the other hand, the diiusion coeecient for two-component systems is shown to be a highly nonlinear function of the rotation velocity. It...

Martensitic Transformation and Elastic Constants