Indication of thermoelastic instability of sliding contact using embedded piezoceramic interlayer

Operation of tribotechnical components and devices is subjected to the instability of the sliding frictional contact, accompanied by an increase in temperature and pressure, which often leads to emergency situations, accidents, etc. In order to prevent such phenomena, a system for monitoring the occurrence of instability is proposed. It is based on an indirect indication of temperature and stress by measuring and analyzing the induction and electric fields in the internal piezoceramic interlayer. In order to model such a monitoring scheme of thermoelastic instability, a non-stationary dynamic contact problem of the thermoelectroelasticity is considered for a rigid body sliding over a half-plane coated by an elastic layer. Friction forces and frictional heat generation at the contact spot are taken into account. Piezoceramic layer is located between the elastic coating and non-deformable base and perfectly bonded to them. The piezoceramic layer is insulated from the thermoelastic coating; its polarization vector is directed along the vertical axis orthogonal to boundaries of the piezoceramic layer. These boundaries have electrodes placed on them with a different supplied voltage. The solution of the problem on the sliding thermoelastic frictional contact is constructed using the Laplace integral transform, which allows to present the basic physical parameters of the problem, such as the temperature, voltage, displacement, induction and electric field strength, the electrostatic potential in the form of contour integrals of the inverse Laplace transform, or as the Laplace convolution. After studying the properties of the integrands and their isolated singular points in the complex plane of the integration variable, the integrals are calculated using the methods of complex analysis. The calculation of the integrals leads to infinite series over the poles of the integrands, which are the eigenvalues of the problem. The solution in this form allows to determine the domains of stable and unstable problem solutions at an infinite time interval. Expressions for the electric current and voltage in the piezoceramic interlayer as well as the expressions for contact temperature and stresses, allow diagnosing the emergence and development of thermoelastic instability of the sliding contact.