IWNET12
IWNET12
Thermodynamical Model of Thermoelastic Interaction in Media of
Anomalous Material Properties and Unconventional Thermoelastic Damp-
ing
B. T. Maruszewski1, A. Drzewiecki1 and R. Starosta1
1 Poznan University of Technology, Institute of Applied Mechanics, ul. Jana Pawªa II 24, 60-965 Poznan,
Poland
Abstract
Dynamical irreversible processes running in the condensed matter are always accompanied by energy dissipation.
The main reason of such fact comes from internal structure of material bodies. Changes of crystal symmetry,
production of defects like dislocations, vacancies, evolution of grain boundaries, internal friction, phase transi-
tions, and the like that occur in various media decide about rate, quality and quantity of that dissipation. Also
a geometry of a material is responsible for the irreversibility of the dynamical processes.
From the thermodynamical point of view the above properties are described mainly by constitutive theories.
In the paper we focus on a constitutive theory in a nonlinear thermoelastic isotropic solid within the extended
thermodynamical model. Stress-strain-temperature relations for materials of so-called normal and negative
properties (negative Poisson's ratio and the negative heat expansion coe cient) have been considered.
That theory can be implemented to unconventional description of the thermoelastic damping phenomenon
observed in thermoelastic materials of nite extent. Material nonlinearity and negative properties have been
also taken into considerations. The theory concerns a situation when instead of the common thermal transfer
there occurs also an additional heat ux coming from periodic deformation (dierent parts of the body are
alternatively compressed and extended causing that sometimes a problem becomes 2D-3D). Hence an addi-
tional dissipation coming from the thermoelastic damping has been observed. Moreover, an unconventional
thermoelastic hysteresis eects have been described.
E-mail: bogdan.maruszewski@put.poznan.pl