Melnyk N. Thermostressed dual-layer conductive state bodies for the actions of pulsed electromagnetic fields

This thesis focuses on the research of thermostressed condition, bearing capacity and saving contact joint properties of double-layer electrically conductive bodies (DLECB) of canonical form under the actions of pulsed electromagnetic fields. Based on the Huber-Mises criterion for homogeneous bodies the methodology for assessing bearing capacity of double-layer electrically conductive body and for saving the properties of contact connection of its component layers has been proposed. The initial correlations of thermomechanics for DLECB have been written in an invariant form in the formulation of the problem in stresses and displacements. A new class of thermomechanics problems of DLECB of canonical form has been formulated - layer with plane-parallel boundaries and hollow cylinder and ball under a uniform non-stationary electromagnetic action. To solve the initial boundary value problems the method has been developed using quadratic approximation of all key functions (tangent component of the magnetic field vector, temperature, normal component of the stress tensor for the layer and radial component of displacement vector for the cylinder and the ball) at the appropriate spatial variable (the thickness for layer and radial for cylinder and ball). Initial tasks for key functions are reduced to the Cauchy problems for integral (total for layers package) characteristics of these functions. Using Laplace transform the general solutions for formulated problems under homogeneous non-stationary electromagnetic action have been obtained. The solutions to these problems for considered bodies under the action of pulsed electromagnetic fields of characteristic types - in the mode with pulse-modulated signal and under the actions of a single electromagnetic pulse have been found. The thermomechanical behavior, bearing capacity and contact joint properties for bodies under consideration have been investigated referred to specific types of pulsed electromagnetic action.