Study of the stress-strain state of the ribbed shell of revolution under external pressure

1979 ◽  
Vol 11 (5) ◽  
pp. 456-460
Author(s):  
G. V. Isakhanov ◽  
A. I. Gulyar ◽  
A. L. Kozak ◽  
Yu. M. Rodichev ◽  
A. S. Sakharov

1975 ◽  
Vol 15 (3) ◽  
pp. 392-399 ◽  
Author(s):  
D. G. Baratov ◽  
V. M. Valov ◽  
R. A. Pzaev ◽  
V. L. Rykov ◽  
I. M. Shalashov


Author(s):  
Natalia A. Gureeva ◽  
Yuriy V. Klochkov ◽  
Anatoly P. Nikolaev ◽  
Vladislav N. Yushkin

The aim of the work is to perform a comparative analysis of the results of analyzing arbitrarily loaded shells of revolution using finite element method in various formulations, namely, in the formulation of the displacement method and in the mixed formulation. Methods. To obtain the stiffness matrix of a finite element a functional based on the equality of the actual work of external and internal forces was applied. To obtain the deformation matrix in the mixed formulation the functional obtained from the previous one by replacing the actual work of internal forces in it with the difference of the total and additional work was used. Results. In the formulation of the displacement method for an eight-node hexahedral solid finite element, displacements and their first derivatives are taken as the nodal unknowns. Approximation of the displacements of the inner point of the finite element was carried out through the nodal unknowns on the basis of the Hermite polynomials of the third degree. For a finite element in the mixed formulation, displacements and stresses were taken as nodal unknowns. Approximation of the target finite element values through their nodal values in the mixed formulation was carried out on the basis of trilinear functions. It is shown on a test example that a finite element in the mixed formulation improves the accuracy of the strength parameters of the shell of revolution stress-strain state.





Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.



2014 ◽  
Vol 46 (11) ◽  
pp. 23-35 ◽  
Author(s):  
Elena A. Velikoivanenko ◽  
Alexey S. Milenin ◽  
Alexander V. Popov ◽  
Vladimir A. Sidoruk ◽  
Alexander N. Khimich


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