Introduction. Thin-walled structures consisting of thin rods, plates and shells are widely used in modern construction, mechanical engineering, shipbuilding, aircraft manufacturing and other fields.

In the field of engineering structures, there are problems of strength under the action of normal distributed loads on a rectangular plate [6, 7, 8, 9]. In modern structures, elastic isotropic plates under an arbitrary distributed load are of great practical application [10, 11, 12]. In the field of studying the strength and stability of a rectangular plate, it is worth noting the works of S.P. Timoshenko [1], S.A. Ambartsumyan and others. In the field of optimal design of thin-walled structural elements, namely in problems of plate bending, the issues of determining the optimal location of supports have not been sufficiently studied. These issues are considered in the works of V.Ts. Gnuni and A.V. Eloyan [2, 3, 4, 5].

Purpose. The purpose of the work is to determine the optimal location of supports for an elastic rectangular plate in bending problems providing the lowest values of the maximum deflection of the plate.

Materials and methods. An analysis of the dependence of the effect of the optimal location of supports along the length of the plate on the aspect ratio of the plate is presented.

Results. Based on the results obtained, it is possible to significantly improve the performance characteristics of isotropic plates.

Conclusions. Determining the optimal location of supports is of particular interest for studying the strength of structures.

The Institute of Geophysics and Engineering Seismology after A. Nazarov National Academy of Sciences Armenia designed and produced a seismic engineering complex that runs in autonomous mode with software package: The complex consists of a system of observational points (surface, borehole), communication and recording units.

In reservoirs of Armenia with total capacity about 1.4 milliard m3 is concentrated, more than 75% of above mentioned amount of water in 20 reservoirs. The reservoirs with technical parameters and class of hydraulic structures (dams) are considered essential and refer to the most responsible hydraulic structures. On proposal of IGES NAN RA for technical modernization projects of the reservoirs seismic engineering system on the dams were obtained on required conditions. This article includes tests and the main results of seismic engineering monitoring of dams and reservoirs.

The issues of strength, stability, effective projecting of an elastic plate taking into account the reaction to the seismic impact are confronted in the engineering constructions. In modern structures, elastic isotropic and anisotropic plates, which are under influence of forces, have practical applications.  Determine the optimal parameters of the location of the transverse piers along the length of the rectangular orthotropic piecewise-homogeneous plate, when the plate between and outside the piers is constructed from orthotropic materials with different elastic modules ensuring the minimum value of the maximum bending of plate. Based on the results obtained, it is possible to significantly reduce the weight of elements of thin-walled structures, as well as save materials and energy.

With the kinematic excitation of a cantilever rod, it has been shown that flexural-shear oscillations begin at the free end of the rod. In this case, internal bulk forces arise in the rod, which oppose 1/2 f (x, t) to external force, and at the free end of the rod, an associated pair F (l, t) and M (l, t) arise. This coupled pair is the true cause of flexural-shear vibrations. The second part of the force f (x,t) goes to create purely shear vibrations.
From the developed new gravitational-vortex theory of seismic stability, it follows that in the design schemes for one-dimensional models there is a fourfold reserve (reserve) for the assessment of forces and moments in the sections of a homogeneous rod. These capabilities make it possible to increase the acceleration on the seismic zoning maps at least twice and to bring the accelerations observed during strong and destructive earthquakes into line with the accelerations used in BRandR.