Abstract
In the mechanical structure of ships, boats and equipment in the marine field, there are many details that were manufactured in the shape of plates, shells, beams with variable-thickness. The calculation of the stress-deformed state of such parts is increasingly demanding with higher accuracy. This paper presents a method to study the stress of beams with variable-thickness according to non-classical theory. The mathematical model was based on the system of equations according to the theory of elasticity. The values of displacement, stress are analyzed as polynomials of higher order than the classical method. The calculation results show that the stress values at the fastening position are significantly higher than that of the classical method.