ДВОВИМІРНІ ЗАДАЧІ ТЕРМОЕЛЕКТРО- ТА ТЕРМОМАГНІТОПРУЖНОСТІ / сторінка 12
ДВОВИМІРНІ ЗАДАЧІ ТЕРМОЕЛЕКТРО- ТА ТЕРМОМАГНІТОПРУЖНОСТІ
KhoroshevThe two-dimensional problems of thermoelectro- and thermomagnetoelasticity.– The manuscript.
The thesis for the Candidate of physical and mathematical sciences degree on specialty 01.02.04 – mechanics of a deformable solid body, Donetsk National University, Donetsk, 2007.
The methods of thermal conductivity, thermoelastic, electroelastic and magneto-elastic problems solving for multiconnected mediums are extended on two-dimen-sional and plane thermoelectroelastic and thermomagnetoelastic problems in thesis. The complex potentials are introduced and investigated, there are obtained the boun-dary conditions for their determination, using the conformal mapping and expansions in series the singularities of functions derivatives are investigated, the boundary conare carried by least-squares method. There are shown the developed methods effectiveness and the received results steadiness by the numerical investigations.
There are given the thermoelectroelastic and thermomagnetoelastic problems solutions for the solid and half-space (plate and half-plane) with cavities and cracks. The detailed numerical investigations of the TEES and TMES (thermoelectroelastic and thermomagnetoelastic states) are carried out. The new mechanical regularities of the thermophysical material properties, geometrical characteristics of holes and cracks, their quantity and position relatively each other and boundary of half-plane influence on the basic TEES and TMES characteristics, internal energy density and SITIF (stress, induction and tension intensity factors) values are determined.
It is shown that temperature field contribution in TEES and TMES is important and one should not be neglected. The piezoeffect impact in the thermal stresses state investigation should not be neglected too. The distance between cavities and cracks as well as linear boundary decreasing leads to the basic TEES and TMES chainternal energy density in bridge points and SITIF values increasing. The crack crossing of the hole counter or half-plane boundary leads to the basic TEES and TMES characteristics values decreasing in vicinity of crossing region and their increasing in other zones simultaneously. Permittivity of materials makes the large impact on basic TEES and TMES characteristics, internal energy density and SITIF. The stresses maximal value in ring from the materials EM6 (PZT-5A) and ММ9 (CoFe2O4) with large permittivity are greater in 8 and 20 times than stresses in rings from EM1(cadmium selenide) and MM8 (Terfenol-D) correspondingly. The pyroelectric (pyromagnetic) coefficients have the great impact on field tension vaIn piezomagnetic plates the stresses and internal energy density values are great-ly more than correspondent values in piezoelectric plate, moreover this effect is higher in a case of multiconnected half-plane.
The investigations results presented in the thesis have both theoretical and prac-tical importance. The proposed methods can be used for а wide variety of engineering problems solving.
Keywords: piezoelectricity, piezomagnetic solid, permittivity, temperature, thermal conductivity, thermoelasticity, thermomagnetoelastic state, internal energy density, SITIF, complex potentials, Cauchy type integrals, least square method, mulisolid, half-space, plate, half-plane.
Реферат на тему: ДВОВИМІРНІ ЗАДАЧІ ТЕРМОЕЛЕКТРО- ТА ТЕРМОМАГНІТОПРУЖНОСТІ