Determination of energy dissipation for heterogeneous solids under nonstationary loading conditions
The complexity of the experimental evaluation of the solid body material behavior in a force field under the contact interaction predetermines the need for developing the theoretical foundations of the methodology to determine energy distribution patterns at the power contact area. Applying the known laws, it is possible to theoretically estimate energy distribution in a solid medium, and on this basis to develop a framework for determining the wave energy in an inhomogeneous medium. The wave energy is used up for absorption and dissipation in an inhomogeneous medium. When in operation, the forced harmonic oscillations occur in the friction pairs, their frequency being up to 100 kHz and above. The values of oscillation frequencies are determined by the relative movement velocity and the contacting surfaces roughness degree. The amplitudes of oscillations depend on the contacting pairs physical-mechanical properties and the external loading conditions. The forced oscillations are the cause of emergence and development of fatigue cracks eventually leading to destruction. This article deals with the behavior of contacting surfaces in terms of the wave energy theory of dissipation energy propagation. The approach to improve methods for determining the components of contact interaction energy of heterogeneous solids under nonstationary loading has been demonstrated taking into account the fatigue stress causing cracks. A mathematical model for the contact interaction energy change on the basis of thermodynamic analogy has been proposed. It has been shown how the nonstationary mode and contact interaction energy amplitude effect on cracks formation in the depth of the contact surfaces material