ВЗАИМОДЕЙСТВИЕ ПЛОСКОЙ ГАРМОНИЧЕСКОЙ ВОЛНЫ С ОГРАНИЧЕННОЙ ПО ВЫСОТЕ ПЛАСТИНОЙ В ГРУНТЕ

Описание

Аннотация

Дано решение плоской задачи о взаимодействии гармонической волны с пластиной конечной длины, находящейся в грунте. Механическое поведение пластины описывается по сдвиговой модели С.П. Тимошенко, а окружающего пластину грунта - уравнением линейной теории упругости. Проведено исследование вибропоглощающих свойств пластины в зависимости от частоты падающей на нее гармонической волны. С практической точки зрения рассматриваемая задача связана с защитой сооружений от воздействия вибраций, формирующихся вдали от линии метрополитена движением поездов.A solution of the two-dimensional task on interaction between the harmonic wave and the plate with the limited height in soil has been provided. The plate surrounded on both sides with the half-spaces filled with soil medium has been used as a vibro-absorbing obstacle. The mechanical behavior of the plate has been described by S.P. Timoshenko's shift model and the mechanical behavior of soil by a linear elasticity theory equation. The main purpose of the paper is to determine the total acceleration vector field inducted by the penetrated and radiated waves in the second half-space. The mathematical formulation of the task includes a model of upcoming wave, soil medium and plate movement equation, infinity conditions, and conditions of soil contact with obstacle. Conditions of free slip have been taken as the contact conditions between the soil and the obstacle. We have considered a closed system of equations, which includes wave equations for scalar and vector potentials, elasticity theory equations for soil mediums, Koshi's relations, physical law, and plate movement equation. The boundary conditions for the plate correspond to a hinged support. To solve this task, all functions have been expanded in trigonometric series that allowed to obtain potential values in the coefficients of the series. To define the integrations constants, the contact conditions between the obstacle and soil have been used. On the basis of the revealed potentials, we have defined displacements on the boundary between the plate and soil and in other points of the second half-space. The vibro-absorbing properties of the plate have been investigated depending on the frequency of the harmonic wave falling on the plate. From the practical point of view, this task is related to protection of buildings from vibrations formed at a distance from underground railways.