scholarly journals Optimization of composite revolution shell by methods of theory of the optimal process

2020 ◽  
Vol 26 (5) ◽  
pp. 28-37
Author(s):  
A.P. Dzyuba ◽  
◽  
V.N. Sirenko ◽  
D.V. Klymenko ◽  
L.D. Levytina ◽  
...  
Keyword(s):  
Composite Material ◽  
Elastic Constants ◽  
Equations Of State ◽  
Experimental Testing ◽  
Necessary Optimality Conditions ◽  
Middle Surface ◽  
Variable Coefficients ◽  
Space Technology ◽  
Fiber Winding ◽  
Revolution Shell

We considered the problem of weight optimization of parameters of multi-layer composite shell produced by the method of continuous cross-winding under axisymmetric loading. Shell layers are placed symmetrically relative to the middle surface. The angles of the reinforcing material winding variable along the meridian and the thickness of layers are taken as the variation parameters. We propose an algorithm of the automated determination of the elastic constants of a composite material variable along the shell meridian anisotropy. The connection of the composite structure with the technological process of shell manufacturing by winding with a reinforcing tape under different angles to the axis of rotation is taken into account. The values of four elastic constants obtained as a result of experimental testing of witness specimens of the composite material along and orthogonal to the reinforcement are used as output. The equations of state of the moment theory of shells of the variable along the meridian orthotropy and wall thickness are obtained as a boundary value problem for a system of ordinary differential equations with variable coefficients. The use of the necessary optimality conditions in the form of the principle maximum of Pontryagin in the presence of arbitrary phrasal restraints made it possible to reduce the emerging multiparameter problem to a sequence of extreme problems of a significantly smaller dimension. This approach greatly simplifies taking into account the conditions of strength reliability, and technological and structural requirements of real design, and the process of finding an optimal project as a whole. The results of the optimization of a two-layer fiberglass shell of rotation are presented in the form of a change in the distribution of layers’ thickness and the glass fiber winding angle. Materials of research can be used to reduce the material consumption of structural elements in rocket and space technology and other branches.

FIRST-PRINCIPLES HIGH-PRESSURE ELASTIC AND THERMODYNAMIC PROPERTIES OF TANTALUM

2011 ◽  
Vol 25 (10) ◽  
pp. 1393-1407 ◽  
Author(s):  
JING-HE WU ◽  
XIAN-LIN ZHAO ◽  
YOU-LIN SONG ◽  
GUO-DONG WU
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Equations Of State ◽  
Debye Model ◽  
Thermal Expansivity ◽  
Orbital Method ◽  
Full Potential ◽  
Body Centered Cubic ◽  
Theoretical Results

The all-electron full-potential linearized muffin-tin orbital method, by means of quasi-harmonic Debye model, is applied to investigate the elastic constant and thermodynamic properties of body-centered-cubic tantalum (bcc Ta). The calculated elastic constants of bcc Ta at 0 K is consistent with the previous experimental and theoretical results. Our calculations give the correct trends for the pressure dependence of elastic constants. By using the convenient quasi-harmonic Debye model, we refined the thermal equations of state. The thermal expansivity and some other thermal properties agree well with the previous experimental and theoretical results.

scholarly journals Finite Element Analysis of the Multilayered Honeycomb Composite Material Subjected to Impact Loading

2017 ◽  
Vol 54 (1) ◽  
pp. 180-179 ◽  
Author(s):  
Raul Cormos ◽  
Horia Petrescu ◽  
Anton Hadar ◽  
Gorge Mihail Adir ◽  
Horia Gheorghiu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Experimental Testing ◽  
Finite Element Models ◽  
The Finite Element Method ◽  
Low Velocity ◽  
Element Analysis ◽  
Element Simulation ◽  
Different Levels

The main purpose of this paper is the study the behavior of four multilayered composite material configurations subjected to different levels of low velocity impacts, in the linear elastc domain of the materials, using experimental testing and finite element simulation. The experimental results obtained after testing, are used to validate the finite element models of the four composite multilayered honeycomb structures, which makes possible the study, using only the finite element method, of these composite materials for a give application.

scholarly journals Stages of information support of development of on-board equipment for spacecraft

2021 ◽  
Vol 5 (3) ◽  
pp. 166-176
Author(s):  
A. A. Kovel
Keyword(s):  
Experimental Testing ◽  
Electronic Devices ◽  
Operating Conditions ◽  
Information Support ◽  
Engineering Practice ◽  
Space Technology ◽  
Successful Operation ◽  
Radio Electronic ◽  
Stage Of Development ◽  
Onboard Equipment

The ground-experimental testing of the elements of space technology is a crucial stage in the creation of space products, in fact, this is the ground «flight» of the devices being created. And how well the operating conditions will be reproduced at this stage and the successful functioning of the devices under the expected conditions is ensured, its successful operation in real flight during the service life depends. The radio electronic devices of the onboard equipment of the spacecraft are one of the essential elements that ensure the fulfillment of target tasks, which should confirm their readiness for the forthcoming work at the stage of groundbased experimental testing. The article discusses the stages of information support for the development of spacecraft onboard equipment, showing the ways to improve the technology of ground-based experimental testing of spacecraft onboard equipment. It is shown that at the present stage of development of the space industry, it has become possible to introduce the methodology of mathematical planning of an experiment into engineering practice. A backlog of applied work on radio-electronic topics h as appeared, showing the possibility of revealing in a full factorial experiment the influence of internal uncontrollable parameters (factors) of electronic components on the experimental results. This removed the obstacle to the implementation of the capabilities of the method in research and improvement of radio electronic devices onboard equipment.

scholarly journals GROUND-BASED EXPERIMENTAL TESTING OF ELEMENTS OF AUTOMATION OF PNEUMATIC-HYDRAULIC SYSTEMS OF ROCKET AND SPACE TECHNOLOGY

2019 ◽  
Vol 27 (4) ◽  
pp. 58-61
Author(s):  
Alexander Nikolaevich Ponomarov
Keyword(s):  
System Development ◽  
Experimental Testing ◽  
Acoustic Method ◽  
Technical Condition ◽  
Rocket Engines ◽  
Hydraulic Systems ◽  
Space Technology ◽  
Functional Diagnostics ◽  
Hydraulic Power ◽  
Liquid Rocket

The design and production of sophisticated technical systems, which include modern rockets and other aircraft, requires their reliability and trouble-free operation. To achieve the required level of reliability of aerospace products, a wide variety of test methods are applied at all stages of the life cycle. One of the most important systems of the launch vehicle is the pneumatic hydraulic power system of the liquid rocket propulsion system. Development of new and improvement of existing methods of control and diagnostics is one way of increasing the design and technological reliability of products of aviation and space technology. The use of functional diagnostics systems for bench and flight tests significantly increases the reliability and efficiency of space rocket technology. Researches are directed on increase of a level of reliability of products of aerospace branch. Application of systems of functional diagnostics is described at bench tests. The results of experimental researches of elements of automatics of pneumatic hydraulic power supply systems of liquid rocket engines are considered. The technique of processing of experimental data of a pulsing-acoustic method of diagnostics with use of the mathematical technology of recognition of images is presented. Deciding rules of recognition of a technical condition of object of diagnosing by results of tests are resulted. The developed method with a high degree of accuracy allows to determine the technical condition of the object of diagnosis as defective or to detect the presence of characteristic defects. Experimental testing and the proposed method of processing the results showed the efficiency of the method.

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