University of Architecture, Civil Engineering and Geodesy

About: University of Architecture, Civil Engineering and Geodesy is a education organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Finite element method & Beam (structure). The organization has 3808 authors who have published 3822 publications receiving 30736 citations. The organization is also known as: Sofia Polytechnic.

A New Approach for Studying Nonlinear Dynamic Response of a Thin Fractionally Damped Plate with 2:1 and 2:1:1 Internal Resonances

Abstract: Dynamic behaviour of a nonlinear plate embedded in a fractional derivative viscoelastic medium and subjected to the conditions of the internal resonances two-to-one and one-to-one, as well as the internal combinational resonances has been studied by Rossikhin and Shitikova in [12, 13]. Nonlinear equations, the linear parts of which occur to be coupled, were solved by the method of multiple time scales. A new approach proposed in this paper allows one to uncouple the linear parts of equations of motion of the plate, while the same method, the method of multiple time scales, has been utilized for solving nonlinear equations. The new approach enables one to solve the problems of vibrations of thin bodies more efficiently.

Character of Soil Cover and State of Land Use Fund in the Absheron Region

Abstract: The morphogenetic analysis of the soils in Absheron administrative region was analyzed, the pecularity of the ecological factors affecting the formation of physical, physico– chemical characters was given. The composition of soil fund is analyzed. An area of clayey, heavy, average, light clayey, sandy soils was calculated. Land grouping was performed for soil profile density. The analysis was performed on administrative–zone units of the areas in the agricultural places (tillage, perennial planting, pastures and hay field), the distribution legislation of the land property forms was studied. Ключевые слова: Апшеронский административный район, гранулометрический состав, мощность почвенного профиля, пашня, многолетние насаждения, сенокосы, формы земельной собственности.

Analysis of Non-linear Vibrations of a Fractionally Damped Cylindrical Shell Under the Conditions of Combinational Internal Resonance

Abstract: Non-linear damped vibrations of a cylindrical shell subjected to the different conditions of the combinational internal resonance are investigated. Its viscous properties are described by Riemann-Liouville fractional derivative. The displacement functions are determined in terms of eigenfunctions of linear vibrations. The procedure resulting in decoupling linear parts of equations is proposed with the further utilization of the method of multiple time scales for solving nonlinear governing equations of motion, in so doing the amplitude functions are expanded into power series in terms of the small parameter and depend on different time scales. It is shown that the phenomenon of internal resonance can be very critical, since in a circular cylindrical shell the internal additive and difference combinational resonances are always present. The influence of viscosity on the energy exchange mechanism is analyzed. It is shown that each mode is characterized by its damping coefficient connected with the natural frequency by the exponential relationship with a negative fractional exponent.