A method of forming a spacecraft adapter layout to meet the requirements of dynamic compatibility by topological and parametric optimization methods

Author(s):  
A.A. Borovikov ◽  
O.N. Tushev

At present, the developers of launch vehicles impose a requirement for dynamic compatibility of the spacecraft with the launch vehicle, which consists in limiting the lower boundary of the first transverse and first longitudinal fundamental (primary) frequencies of the natural vibrations of the spacecraft fitted with an adapter of relatively rigid base. One of the tasks that must be solved in order to meet this requirement is the development of the spacecraft adapter layout. The traditional process of designing the adapter consists in developing its design on the basis of analogues and carrying out verification analysis with subsequent refinement of the design to meet the strength and stiffness requirements. However, this approach takes a lot of time and is not adaptable to constant changes in the input data at the initial design stage. The article presents a technique allowing the adapter layout to be quickly designed. The layout is determined to a greater extent by calculations using the topological and parametric optimization methods. The application of the developed technique is shown on the example of the development of an adapter for a promising spacecraft. It should be applied in the early stages of design. The results obtained by the method should be used as input data and recommendations for the design of the adapter.

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 64
Author(s):  
Liankang Wei ◽  
Hongzhan Lv ◽  
Kehang Yang ◽  
Weiguang Ma ◽  
Junzheng Wang ◽  
...  

Purpose: We aim to provide a systematic methodology for the optimal design of MRD for improved damping capacity and dynamical adjustability in performing its damping function. Methods: A modified Bingham model is employed to model and simulate the MRD considering the MR fluid’s compressibility. The parameters that describe the structure of MRD and the property of the fluid are systematically examined for their contributions to the damping capacity and dynamically adjustability. A response surface method is employed to optimize the damping force and dynamically adjustable coefficient for a more practical setting related to the parameters. Results: The simulation system effectively shows the hysteretic characteristics of MRDs and shows our common sense understanding that the damping gap width and yoke diameter have significant effects on the damping characteristics of MRD. By taking a typical MRD device setup, optimal design shows an increase of the damping force by 33% and an increase of the dynamically adjustable coefficient by 17%. It is also shown that the methodology is applicable to other types of MDR devices. Conclusion: The compressibility of MR fluid is one of the main reasons for the hysteretic characteristics of MRD. The proposed simulation and optimization methods can effectively improve the MRD’s damping performance in the design stage.


Author(s):  
G.B. Kryzhevich ◽  
A.R. Filatov

Объектом исследования является крышка люкового закрытия сухогрузного судна, служащая для обеспечения непроницаемости грузовых помещений и перевозки на ней грузов и обеспечивающая безопасность сухогрузных судов и осуществляемой на них морской перевозки грузов. Большая материалоемкость крышек снижает экономическую эффективность судна, ведет к необходимости использования мощных и массогабаритных средств подъема крышек (для съемных люковых закрытий), либо поворота и передвижения крышек (для шарнирно-откидных закрытий). Целью статьи является существенное снижение материалоемкости крышек люкового закрытия за счет рационального выбора их материала и конструктивного оформления при одновременном обеспечении требуемого уровня их надежности. Параметрическая оптимизация традиционной стальной крышки люкового закрытия сухогрузного судна проекта RSD59 может привести к снижению ее массы не более чем на 15-17. Поэтому для достижения цели работы решается задача оптимизации конструкции алюминиевой крышки на основе комплексного подхода, состоящего в последовательном использовании топологических и параметрических оптимизационных методов и выполнении на последней стадии работы снижения уровня концентрации напряжений путем оптимизации формы узлов крышки. При этом на стадии выбора конструктивно-силовой схемы крышки применяются приёмы топологической оптимизации, на стадии выбора толщин и параметров силовых элементов способы параметрической оптимизации, а на стадии конструктивно-технологического оформления узлов методы оптимизации формы. Выполненные расчетные исследования привели к следующим основным результатам: к выявлению прогрессивных конструктивно-силовых схем и конструктивно-технологических решений, обеспечивающих значительное снижению массы крышек люковых закрытий при умеренных затратах на их изготовление к высоким оценкам эффективности использования современных алюминиевых сплавов для изготовления люковых закрытий, способствующим существенному снижению их материалоемкости (примерно двукратному и более по сравнению с использованием стали), улучшению условий их функционирования и проведения погрузочно-разгрузочных работ на сухогрузных судах к выводу об эффективности использования разработанных конструкторских решений для крышек люковых закрытий при создании перспективных сухогрузных судов.A bulk carrier hatch cover, which provides cargo compartments impermeability and cargo transportation on the cover, as well as safety of bulk carriers and sea cargo transportation in them, is studied. Cover high material consumption decreases vessel profitability, causes the necessity to use either powerful and mass-dimensional cover lifting devices (for removable hatch covers) or covers rotation and movement (for hinged covers). The purpose of this paper consists in considerable decrease of hatch cover material consumption through rational selection of covers material and design at provision of the required covers reliability level. Parametric optimization of a conventional steel cover of RSD59 project bulk carrier could result in cover mass decrease by more than 15 to 17. Therefore, to achieve the work purpose, a problem of aluminum cover structural optimization was solved based on a comprehensive approach that consisted in successive use of topologic and parametric optimization methods and decrease of the stress concentration level at the last step via cover assemblies shape optimization. At that topological optimization methods were applied at the stage of selecting cover structural arrangement parametric optimization methods were applied at the stage of selecting load-carrying elements thickness and parameters, and shape optimization methods were used at the stage of structural and technology design of assemblies. The performed calculation studies resulted in the following: revealing the advanced structural arrangements and design and technology solutions that provide considerable hatch covers mass decrease at reasonable costs for their manufacture high assessment of using advanced aluminum alloys for manufacturing hatch covers that promote considerable decrease of their material consumption (approximately up to twofold or greater in comparison with steel), improving conditions of cover functioning and handling operation in bulk carriers conclusion on effectiveness of using developed design solutions for hatch covers when creating prospective bulk carriers.


Author(s):  
V. E. Afanasjevska ◽  
A. A. Tronchuk ◽  
M. L. Ugryumov

When projecting the gas turbine an important problem is an ensuring the high values of gas turbine parameters and required gas turbine operating characteristics on the different operating conditions. These requirements can be reached by engine function units system perfecting on base of multicriterion stochastic optimization problems solution. Three stochastic optimization problems definitions were formulated. Each problem has own features and can be used for different application solution. These applied problems are: M-problem can be used on the technical system unit conceptual design stage; V-problem can be used for the problem solution of tolerancing during the technical system unit production; P-problem can be used for interval analysis of technical system functional unit. The multicriterion stochastic optimization problem rational decision is realized by the evolutional method. This method makes it possible to find the solution with given accuracy by attraction the less information recourses than standard methods. In the stochastic optimization problems definitions the input data random character is taken into account. It makes it possible to find the optimal values of desired parameters. These parameters ensure the maximal probability of finding the objective function in given range.


2021 ◽  
Vol 9 (2) ◽  
pp. 51-55
Author(s):  
Leysan Akhtyamova

A technique is proposed for the optimization of supports in the form of truncated conical shells with a stepwise change in the wall thickness. The potential energy of deformation, the maximum displacement of the structure and the first frequency of natural vibrations were selected as optimization criteria. The solution is performed using nonlinear optimization methods in combination with the finite element method in the Matlab environment.


2021 ◽  
Vol 24 (2) ◽  
pp. 49-54
Author(s):  
Yevgeny E. Krivobokov

This article presents the methods of complex computational and analytical assessment of ensuring electromagnetic compatibility of technical means (electrical, electronic and radio-electronic means of launch vehicles and spacecraft). These methods allow us to conduct a comprehensive computational and analytical assessment of the electromagnetic compatibility of the technical means of rocket and space technology, which in its essence allows us to assess the mutual influence of the technical means of rocket and space technology already at the design stage of rocket and space technology objects. The analysis of the results of the assessment of the electromagnetic compatibility of the technical means of rocket and space technology allows us to develop organizational and technical measures aimed at ensuring the electromagnetic compatibility of the technical means of rocket and space technology at all stages of the life cycle of objects of rocket and space technology. To assess the electromagnetic compatibility of the technical means of rocket and space technology, an integrated approach was chosen due to the large dimension of the initial data and the variety of possible variants of interference penetration.


1976 ◽  
Vol 20 (02) ◽  
pp. 67-78
Author(s):  
Carl Arne Carlsen ◽  
Dag Kavlie

A program system, INDETS, for computer-aided design of tanker structures has been developed. The system, which is the result of a joint effort of the Norwegian Institute of Technology, Trondheim, and the Aker Group, Oslo, is considered an effective tool for practical design. A design module of INDETS for tanker transverse-plane bulkheads is presented. The girder system is analyzed by a three-dimensional frame model including the surrounding structure as substructures. Two optimization methods, the Stress Ratio Technique and the Sequential Unconstrained Minimization Technique, are applied. A number of parametric variations on topology have been performed, and the depth and breadth have been varied to derive curves for estimating the weight of bulkheads at the preliminary design stage. As a conclusion, a simple-formula is presented.


2009 ◽  
Vol 419-420 ◽  
pp. 673-676
Author(s):  
Xiao Dong Xing ◽  
Li Xun Zhang ◽  
Li Quan Wang ◽  
Jun Liu

An Ocean Casing Pipes Centering Equipment is designed and implemented. Utilizing the equipment, two casing pipes can be fastened together by means of welding. The equipment can automatically carry out clamping and centering two casing pipes, and then the butt welding is conducted at their adjacent ends. In the development of this equipment, some advanced means, such as digital modelling and FEA (Finite Element Analysis), are taken full advantage of. First, all the parts’ 3D models are built with Pro/Engineer. Then, those digital parts is assembled in Pro/E assembly environments. Meanwhile, assembly interference detection is executed. Furthermore, by means of universal finite-element software,the finite element model is constructed. The strength and stiffness of the structure is calculated and analyzed so that the faults of the equipment can be found out in design stage. Through repeating this designing and verifying course, the structure of the equipment can be improved.


Author(s):  
Youngwon Hahn ◽  
John I. Cofer

The optimization techniques most widely used in various industrial fields for structural optimization generally can be placed into two categories: parametric optimization and non-parametric optimization. In parametric optimization, the parametric variables defining a geometric model are used as design variables. For example, all dimensions defining a structural shape in a CAD (Computer-Aided Design) system can be used as parameters in an optimization process to achieve a desired objective. In non-parametric optimization, an initial outer boundary of the geometry is defined and the optimization process either removes mass without changing the node locations in the calculation mesh (topology optimization) or directly manipulates the node locations (shape optimization) to achieve a desired objective. Nowadays, the combination of both parametric and non-parametric optimization methods can provide an attractive approach to satisfy the requirements of advanced levels of structural performance. While optimization methods have been widely used in many turbomachinery applications, such as turbine and compressor blading, combustors, and casings, in the rotordynamics field, relatively little work has been done to investigate methods for the overall optimization of rotor-bearing-support structures to achieve desired system behavior. In this paper, a combined parametric and non-parametric optimization method is applied to a rotor-bearing-support structure in order to achieve the desired critical speed and unbalance response. The bearing design variables are selected as parametric design variables and topology optimization is applied to the support structure. The entire optimization workflow is constructed in the commercial software Isight, and Abaqus and ATOM (Abaqus Topology Optimization Module) are used for rotordynamics analysis and topology optimization. The desired critical speed and unbalance response can be obtained with the optimized topology of the support structure.


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