In this work, the study of the problems associated with the propagation of natural waves in multilayer viscoelastic cylindrical bodies with a weakened mechanical contact is discussed. A detailed analysis of well-known works devoted to this problem is given. A mathematical formulation, a technique, and an algorithm for studying the damping properties of natural waves in multilayered cylindrical mechanical systems with a weakened mechanical contact are developed. The solution of the considered problem was obtained by the method of separating the variables based on the theory of potential functions (special functions).The complex roots (phase velocities) of the dispersion transcendental equation for given wavenumbers are determined numerically by the Muller method. The phase and group velocities of a structurally heterogeneous mechanical system at various geometric and physical-mechanical parameters for the elements of the mechanical system are investigated. It was established that the real parts of the wave velocity will increase by only a few percent, and the imaginary parts for structurally heterogeneous mechanical systems radically change; the phase velocities (real parts of the complex velocity) of natural waves with an increasing wave numbers around the cylinder circumference of structurally heterogeneous mechanical systems first decrease and then begin to increase. A mechanical effect was discovered for structurally heterogeneous mechanical systems, which provides damping for the waves of the mechanical system as a whole.

In this article, an exact mathematical model for the deformation of a viscoelastic (or polymer) conical shell and algorithms for its study is developed. Nonlinear mathematical models for the deformation of ribbed conical shells under dynamic loaded are obtained. A study of the stress-strain state and stability of viscoelastic panels of conical shells and truncated closed and revealed some characteristic features.

ISRA (India) = 4.971 ISI (Dubai, UAE) = 0.829 GIF (Australia) = 0.564 JIF = 1.500 SIS (USA) = 0.912 РИНЦ (Russia) = 0.126 ESJI (KZ) = 8.997 SJIF (Morocco) = 5.667 ICV (Poland) = 6.630 PIF (India) = 1.940 IBI (India) = 4.260 OAJI (USA) =

The problem of calculating the dynamic stress-strain state of viscoelastic rectangular isotropic plates on a deformed base, including freely lying on the ground medium under the influence of vibration loads, is solved. Several models of the dynamic reaction of the base are considered and a qualitative comparison of the results is carried out. In the calculations, the Gauss method, the Mueller method and the smallest residuals were used.

The paper presents the results of full-scale experimental studies on the pattern of propagation of seismic blast waves in the soil and the behavior of the underground cylindrical thin-walled shell under seismic effects of underground instantaneous explosions. It was established that the rise time of the maximum of the underground structure in the waveform does not correspond in value with the time of the rise of the maximum of the soil environment surrounding the underground structure. From the above it follows that, with moderate attenuation, the logarithmic decrement is the ratio of the energy scattered in one cycle to the doubled maximum potential energy of the cycle. The results obtained are important in engineering analysis and prediction of the behavior of underground thin-walled structures.