#### 539.376 Modeling of load-bearing capacity of a smooth cylindrical shell under conditions of material creep

##### Dubrovin V. M. (Bauman Moscow State Technical University), Semyonov K. S. (Bauman Moscow State Technical University/RSC Energia)

doi: 10.18698/2309-3684-2017-3-3848

The study introduces a method for calculating the load-bearing capacity of a smooth cylindrical shell, which has been under the action of axial and transverse loads for a long time. We assume that with prolonged loading, the shell material is subject to the phenomenon of creep, which in turn affects the load-bearing capacity of the shell. As a result, we obtained relations that made it possible to estimate this influence.

Dubrovin V.M., Semenov K.S. Modeling of load-bearing capacity of a smooth cylindrical shell under conditions of material creep .Маthematical Modeling and Computational Methods, 2017, №3 (15), pp. 38-48

#### 539.3 Modeling of loads on a composite cylindrical shell with an elastic filler

##### Dubrovin V. M. (Bauman Moscow State Technical University), Semyonov K. S. (Bauman Moscow State Technical University/RSC Energia)

doi: 10.18698/2309-3684-2019-1-2742

A method for calculating the loads on a composite cylindrical shell, consisting of external and internal shells connected by a system of elastic transverse supports, is proposed. Between the shells is an elastic filler. The method takes into account the geometry and mechanical characteristics of the shells, the elastic characteristics of the transverse supports and the physico-mechanical properties of the material of the elastic aggregate. In solving the problem, it is assumed that the material of the elastic aggregate satisfies the basic relations of the theory of elasticity, and the elastic characteristics of the aggregate under dynamic loading correspond to the characteristics under static loading. This allows you to use the results to solve problems in both static and dynamic formulations. By choosing a different combination of characteristics of the shells and the elastic filler, it is possible to provide the most favorable loading conditions for both the inner and outer shells, depending on the statement of the problem. As an example, the loads on the inner shell were studied depending on the characteristics of the outer shell and the specific stiffness of the elastic filler. Similarly, estimates of the loads acting on the outer shell can be obtained.

Дубровин В.М., Семёнов К.С. Моделирование нагрузок на составную цилин-дрическую оболочку с упругим заполнителем. Математическое моделирование и численные методы, 2019, № 1, с. 27–42.

#### 519.6 Modelling of quasi-static reliability of technical system design

##### Dubrovin V. M. (Bauman Moscow State Technical University), Semyonov K. S. (Bauman Moscow State Technical University/RSC Energia)

doi: 10.18698/2309-3684-2018-3-3848

We consider the technical system, comprising a plurality of structural elements operating under the influence of a complex external loads. For such a system, we proposed a method for calculating the reliability criterion for the occurrence of one or more of the limit states design elements.

Дубровин В.М., Семёнов К.С. Моделирование квазистатической надежности конструкции технической системы. Математическое моделирование и численные методы, 2018, № 3, с. 38–48.

#### 539.376 Simulation of the bearing capacity of a cylindrical shell reinforced by a power set under conditions of material creep

##### Dubrovin V. M. (Bauman Moscow State Technical University), Semyonov K. S. (Bauman Moscow State Technical University/RSC Energia)

doi: 10.18698/2309-3684-2018-2-3246

Cylindrical shell, which is under the influence of considerable loads for a long time, can lose the ability to withstand the level of these loads, as its carrying capacity decreases. This is due to the fact that the shell material is subject to the creep phenomenon. As studies [1-3] show, creep is noticeably manifested even at normal temperature and stresses, much lower than the yield point of the shell material. Experimental and theoretical work on the stability of shells show [4-5] that the main reason for reducing the critical load for real shells in comparison with ideal shells is the initial design imperfections. Therefore, it is to be expected that additional deflections that arise as a result of creep deformation have a significant effect on the critical load (bearing capacity) of the shell. A method is proposed for calculating the load-bearing capacity of a cylindrical shell reinforced by a longitudinal (stringers) and a final (frame) power set under the action of axial and transverse loads, as well as internal excess pressure. As an example, a shell is considered, the material of which is an aluminum-magnesium alloy AMg6-M and AMg6-H. The dependence of the bearing capacity on the operating time is obtained.

Дубровин В.М., Семенов К.С. Моделирование несущей способности подкрепленной силовым набором цилиндрической оболочки в условиях ползучести материала. Математическое моделирование и численные методы, 2018, № 2, с. 32–46.