Diagnostics of changes in the phase composition and stress-strain state of laminated materials and their components by measuring the magnetic characteristics

2017 ◽  
Author(s):  
E. A. Putilova ◽  
E. S. Gorkunov ◽  
S. M. Zadvorkin ◽  
L. S. Goruleva
2021 ◽  
Vol 4 ◽  
pp. 61-68
Author(s):  
Nina Yakovenko ◽  
◽  
Andrey Bondarchuk ◽  
Oksana Kovalchuk ◽  
◽  
...  

Axisymmetric problem of heat pulse irradiation of a cylindrical solid is considered. Nonlinear behavior of the material is described by the generalized Bodner-Partom model of flow. The nature of generalization lies in applying the rule of mixtures for the determination of parameters of the model responsible for yield point and ultimate strength. The considered model enables one to estimate the residual stress-strain state more exactly. During subsequent in-service loading of cylindrical solids, this state strongly affects the fatigue resistance of elements. The problem is solved by the time step integration method, iterative method, and finite element method. In each time step, we realize a double iteration process. The first is connected with the integration of the system of nonlinear equations of flow, the second with the solution of equations of motion and heat conduction. The calculations are performed on a grid FEM, especially in the region of irradiation, for the correct modeling of thermomechanical behavior of the material. The grid parameters are chosen with the help of the criterion of practical convergence of the solutions. The investigation of the stress-strain state of an inelastic material with regard for the dependence of parameters of the flow model on the phase composition of a material is carried out by using of numerical simulation. The main result is the following: qualitative and quantitative effects of phase composition influence on inelastic characteristics are established, namely change of tensile residual stresses on compression. The results obtained in the work can be used in calculations of parameters of surface hardening technologies.


2007 ◽  
Vol 103 (3) ◽  
pp. 311-316 ◽  
Author(s):  
E. S. Gorkunov ◽  
S. M. Zadvorkin ◽  
S. V. Smirnov ◽  
S. Yu. Mitropol’skaya ◽  
D. I. Vichuzhanin

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.


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