In the present paper, the growth rate of eigenvalues for the fourth-order spectral problem with nonsmooth solutions is obtained. It arises when we apply the Fourier method to the mathematical model, describing small free vibrations of a mechanical system consisting of pivotally connected rods. We assume that at the connection points there are springs that respond to rotation, while the system is in the external environment with localized features, leading to a loss of smoothness of the solution. The analysis of the problem is based on the pointwise approach proposed by Yu. V. Pokorny, and proved to be effective in studying linear boundary problems of the second and fourth orders with continuous solutions (an exact parallel with oscilation theory of ordinary differential equations is constructed).

В статье уточнена скорость роста собственных значений одной спектральной задачи четвертого порядка с негладкими решениями. Анализ задачи опирается на предложенный Ю. В. Покорным поточечный подход, показавший свою эффективность при изучении линейных граничных задач второго и четвертого порядков с непрерывными решениями.