Technical mechanics最新文献

{"title":"Assessment of thrust chamber stability margins to high-frequency oscillations based on mathematical modeling of coupled ‘injector – rocket combustion chamber’ dynamic system","authors":"O. Nikolayev, I. D. Bashliy","doi":"10.15407/itm2022.01.003","DOIUrl":"https://doi.org/10.15407/itm2022.01.003","url":null,"abstract":"High-frequency instability of a liquid-propellant rocket engine (LRE) during static firing tests is often accompanied by a significant increase in dynamic loads on the combustion chamber structure, often leading to a chamber destruction. This dynamic phenomenon can also be extremely dangerous for the dynamic strength of a liquid-propellant rocket engine. The calculation of acoustic combustion product oscillation parameters is important in the design and static firing tests of such rocket engines. The determination of the oscillation parameters (natural frequencies and stability margins such as oscillation decrement) is one of the problems solved in the LRE design period as part of the development of measures to ensure the engine stability. The main aim of the paper is to develop a numerical approach to determining the parameters of acoustic oscillations of combustion products in liquid-propellant rocket engines combustion chambers taking into account the features of combustion space configuration and the variability of gaseous medium physical properties depending on the axial length of the chamber, acoustic impedance in critical throat and dissipation effects (damping experimental values) in the shell structure and the gas media in the chamber. The approach is based on mathematical modeling of the coupled ‘chamber shell structure – gas’ dynamic system by using the finite element method and the CAE (Computer Aided Engineering) system. The developed approach testing and further analysis of the results for the RD 253 engine using nitrogen tetroxide and unsymmetrical dimethylhydrazine as a propellant pair were carried out. The dynamic system shapes and frequencies of longitudinal, tangential and radial modes are determined. The results of mathematical modeling of the dynamic system indicate a satisfactory agreement of the calculated decrements of the first longitudinal oscillation mode and third tangential oscillation mode with the experimental decrements obtained by hot-fire tests data. From system harmonic analysis of the thrust chamber, it follows that the dynamic pressure gain factor of the gas media in the chamber at the first longitudinal mode frequency is 1.6 times greater than the system dynamic gain in the tangential mode. At the same time, the oscillation decrement for the system tangential mode is 2 times smaller than that of the first longitudinal mode. This means that the thrust chamber tangential mode is more dangerous and can lead to rocket engine combustion instability. The effect of the injector on the high-frequency stability of the combustion chamber and the possibility of partial suppression of combustion chamber thermoacoustic oscillations by adjusting the high-frequency dynamics of the injector are shown theoretically.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128704693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creep failure time prediction using the reliability theory","authors":"V. Poshyvalov","doi":"10.15407/itm2022.01.036","DOIUrl":"https://doi.org/10.15407/itm2022.01.036","url":null,"abstract":"This paper proposes a probabilistic model of structural material creep failure, which is based on the reliability theory. It is assumed that for specimen failure under the action of a constant load, there exists a functional relationship between the creep strain accumulated to a given time and the nonfailure probability at that time. This assumption and the fact that in most cases the failure rate function and a typical creep strain rate vs. time curve are nonmonotonic and U-shaped made it possible to obtain the nonfailure probability. The creep and the long-term strength equations are adopted in power law form with account for specimen necking in the deformation process, For the power law of creep without strengthening, relationships are obtained for determining the average time to failure and the rms deviation of the long-term strength of a rod tensioned with a constant force in creep. The long-term strength variation coefficient is determined; the coefficient has two finite limits. It is shown that with decreasing strength the brittle zone demonstrates an increase in measured failure time spread at equal stress levels, while in the tough zone this is absent. Theoretical calculations are compared with long-term strength test results for 12Cr18Ni10Ti corrosion-resistant steel at 850°C. The material constants were determined from the results of creep and long-term strength test data processing. The theoretical creep failure time for the linear dependence of the failure rate function on the creep strain rate is less than for the quadratic one, while the rms deviations are greater. In both cases, the theoretical results are in satisfactory agreement with the experimental data both for the failure time and for its rms deviation.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126483076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical analysis of the stress state of honeycombs made by additive technologies","authors":"I. Derevianko, B. Uspensky, K. Avramov, O. Salenko","doi":"10.15407/itm2022.01.042","DOIUrl":"https://doi.org/10.15407/itm2022.01.042","url":null,"abstract":"This paper proposes an approach to the experiment-and-calculation analysis of the tension of honeycombs made by FDM additive technologies. The approach includes experimental tension analysis. Tension tests of honeycombs were conducted on a certified TiraTest 2300 universal tension testing machine. To do this, sets of honeycomb samples were prepared. The method of honeycomb manufacturing by FDM additive technologies is described. The vertices of a honeycomb cell row are fixed in the vise-type clamps of the tension testing machine. The experimental analysis is accompanied by a numerical finite-element simulation of tension tests. To simulate honeycomb tension, nine mechanical characteristics of the material in material axes must be known. These nine parameters are considered in the paper. A direct finite-element simulation of a honeycomb with account for the deformation of all its cells was performed. To provide the uniformity of sample deformation in a physical experiment, the sample is loaded by setting the displacement of one of its ends to a constant value. In doing so, the other end is clamped. As follows from the experimental analysis, before failure the honeycomb cell end displacements are comparable with the honeycomb cell thickness. Because of this, the geometrically nonlinear deformation of the honeycomb cells in tension is accounted for in the calculations, and a nonlinear problem is solved using ANSYS. The direct simulation of honeycombs and the analysis of their homogenized model give different results. In the direct simulation of honeycombs, they are considered as thin-walled beams working in bending. In this case, the geometrical nonlinearity contributes significantly to the structural deformation. For plate tension (homogenized model), the contribution of the geometrical nonlinearity is very small, Because of this, the stress-strain response is close to linear.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126319514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asessment of dynamic loads on a motor-car train with a passive safety system in its collision with a large road vehicle","authors":"M. Sobolevska, D. Horobets","doi":"10.15407/itm2022.01.051","DOIUrl":"https://doi.org/10.15407/itm2022.01.051","url":null,"abstract":"A topical problem of the home railway transport is motor-car train renewval, speed increase, and safety improvement in accordance with the Ukrainian State Standards DSTU EN 12633 and DSTU EN 15227, which specify the passenger car crashworthiness and passive safety, respectively, in emergency collisions with various obstacles. Relying on the world experience, researchers of the institute of Technical Methanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine developed a passive protection concept for home high-speed passenger trains in emergency collisions according to the DSTU EN 15227 requirements, proposals on the passive propection of a home motor-car train head car, lower- and upper-level honeycomb energy-absorbing devoces (EAD 1 and UL EAD, respectively) for the head car front part, and EAD 2 and EAD 3 low-level devices to be installed in intercar connecteions. The upper- and lower-level protective devices for home motor-car trains were developed based on finite-element simulation results using previous experience in the development of a passive protection device for a high-speed passenger locomotive and the results of a successful crash test of its proptotype. For Scenario 3, which chraracterizes a collision of a reference motor-car train at 110 km/h with a 15 t large road vehicle at a railway crossing, a model of a large deformable obstacle (LDO) was developed in compliance with the DSTU EN 15227 requirements. Finite-element models were developed to determine the force characteristics of interaction between the proposed head car passive protection devices and an LDO. The aim of this paper is to determine dynamic loads on a motor-car train equipped with passive protection devices in its collision with a large road vehicle. Based on a mathematical collision model for identical motor-car trains, a mathematical model was developed for a collision of a reference train with a large road vehicle at a railway crossing (Scenario 3) with account for the determined force characteristics of obstacle ? two EAD 1 low-level devices and obstacle ? two UL EAD upper-level devices interaction and the in-collision work of the head car structure. Dynamic loads on the cars of a reference train with a passive safety system (a head car mass of 80 t and intermediate car masses of 50 t or 64 t) were analyzed for its collision by Scenario 3. Two EAD layouts in the head car front part were studied. It was found that the proposed passive protection of the reference train cars meets the DSTU EN 15227 criteria for Scenario 3 for both EAD layouts and the determined variants of lower- and upper-level EAD use according to the intermediate car masses. The proposed mathematical model of dynamic loads on a passenger train with a passive safety system in its collision with a large road vehicle and the results obtained may be used in designing an up-to-date high-speed motor-car train to the DSTU EN 15227 requirements.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127418904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Refinement of the rail–wheel contact pair to improve rail–wheel interaction conditions for railway vehicles with an increased axle load","authors":"T. Mokrii, I. Malysheva, N. Bezrukavyi, I.M. Ladyhin","doi":"10.15407/itm2021.04.129","DOIUrl":"https://doi.org/10.15407/itm2021.04.129","url":null,"abstract":"At present, one of the global trends in railway transport development, which becomes clearer and clearer, is increasing the axle load of freight cars, which gives a considerable economic benefit. In this connection, of importance is not only the car design, but also the car capacity utilization factor: the higher this factor, the more economically efficient the car use. Because of this, one of the priority global lines in increasing the volume of fright traffic and the railway operation efficiency is increasing the carrying capacity of freight cars. Preparing the railways for cars with increased axle loads calls for the development of measures to decrease the track deformability, in particular by choosing appropriate wheel and rail profiles. The aim of this work was to develop recommendations on refining the wheel?rail contact pair to improve curve negotiation by railway vehicles with an increased axle loads on the Ukrainian railways. This paper presents the proprietary R-ITM wear-resistant railhead profile. The effect of the new profile on wheel?rail interaction in negotiating a curve of radius 300 m at a constant speed was studied for different cars. In doing so, emphasis was on wheel?rail interaction for a new-generation freight car on 18-9817 trucks with an axle load increased to 36 tf. The studies conducted made it possible to formulate the following recommendations: to improve curve negotiation by railway vehicles with increased axle loads, reduce the adverse effect on the track and improve traffic safety, new proprietary contact pair profiles are recommended: the ITM-73-03 wheel profile for cars, and the R-ITM railhead profile for outer rails together with the standard R65 railhead profile for inner rails.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129276068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptation of gas-dynamic characteristic arrays to automated ballistics support of spacecraft flight","authors":"T. H. Smila, L. Pecherytsia","doi":"10.15407/itm2021.04.089","DOIUrl":"https://doi.org/10.15407/itm2021.04.089","url":null,"abstract":"The current level of the design and use of new-generation spacecraft calls for a maximally automated ballistics support of engineering developments. An integral part of the solution of this problem is the development of an effective tool to adapt discrete functions of gas-dynamic characteristics to the solution of various problems that arise in the development and use of space complexes. Simplifying the use of bulky information arrays together with improving the accuracy of approximation of key coefficients will significantly improve the ballistics support quality. The aim of this work is to choose an optimum method for the approximation of a discrete function of two variable spacecraft aerodynamic characteristics. Based on the analysis of the advantages and drawbacks of basic methods of approximation by two fitting criteria: the maximum error and the root-mean-square deviation, recommendations on this choice were made. The methods were assessed by the example of the aerodynamic coefficients of the Sich-2M spacecraft’s simplified geometrical model tabulated as a function of the spacecraft orientation angles relative to the incident flow velocity. Multiparameter numerical studies were conducted for different approximation methods with varying the parameters of the approximation types under consideration and the approximation grid density. It was found that increasing the number of nodes of an input array does not always improve the accuracy of approximation. The node arrangement exerts a greater effect on the approximation quality. It was established that the most easily implementable method among those considered is a step interpolation, whose advantages are simplicity, quickness, and limitless possibilities in accuracy improvement, while its significant drawbacks are the lack of an analytical description and the dependence of the accuracy on the grid density. It was shown that spline functions feature the best approximating properties in comparison with other mathematical models. A polynomial approximation or any approximation by a general form function provide an analytical description with a single approximating function, but their accuracy of approximation is not so high as that provided by splines. It was found that there exists no approximation method that would be best by all criteria taken together: each method has some advantages, but at the same time, it has significant drawbacks too. An optimum approximation method is chosen according to the features of the problem, the priorities in approximation requirements, the required degree of approximation, and the initial data organization method.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134148310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of the force characteristic of head car’s passive safety system – large road vehicle interaction in a collision","authors":"M. Sobolevska, D. Horobets, S. Syrota","doi":"10.15407/itm2021.04.118","DOIUrl":"https://doi.org/10.15407/itm2021.04.118","url":null,"abstract":"One of the priorities of the National Economic Strategy of Ukraine for the Period up to 2030 is the development of the transport sector, in particular railway vehicle renewal, the introduction of high-speed railway passenger transport, and railway traffic safety improvement. The home motor-car trains must be renewed in compliance with new home standards harmonized with European ones, among which one should mention the Ukrainian State Standard DSTU EN 15227, which specifies the passive safety of a passenger train in its emergency collisions with different obstacles. New car designs must provide not only effective up-to-date braking systems to prevent emergency collisions, but also passive safety systems with energy-absorbing devices. The main purpose of these devices is to reduce the longitudinal forces in the intercar connections and the car accelerations to an acceptable level for the three collision scenarios specified in the DSTU EN 15227. The Department of Statistical Dynamics and Multidimensional Mechanical Systems Dynamics, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, developed a passive protection concept for home high-speed passenger trains in emergency collisions by the DSTU EN 15227 scenarios, proposals on the passive protection of a motor-car train head car, and honeycomb designs of lower- and upper-level energy-absorbing devices (EAD 1 and UL EAD, respectively), which are integrated into the head car front part and serve to damp the major part of the impact energy in front collisions with obstacles. This paper considers DSTU EN 15227 Scenario 3: a collision of a reference motor-car train at a speed of 110 km/h at a railway crossing with a large 15 t road vehicle, which is simulated as a large-size deformable obstacle (LSDO). The aim of the paper is to determine the force characteristic of the interaction of energy-absorbing devices mounted on the head car front part with a large road vehicle in a collision to assess the compliance of the proposed passive protection with the normative requirements. Finite-element models were constructed to analyze the plastic deformation of the elements of the EAD 1 – LSDO, UL EAD – LSDO, and EAD 1 – UL EAD –LSDO systems in a collision with account for geometric and physical nonlinearities, steel dynamic hardening as a function of the impact speed, and varying contact interaction between the elements of the systems considered. The studies conducted made it possible to determine the force characteristics of energy-absorbing device – obstacle interaction and the total characteristic of the contact force between two lower-level devices and two upper-level ones as a function of the obstacle center of mass displacement in a collision. The proposed mathematical models and the calculated force characteristics may be used in the study of the dynamics of a reference motor-car train – large road vehicle collision with the aim to assess the","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131735120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of a “green” propellant in low-thrust control jet engine systems","authors":"V. I. Timoshenko, L.K. Patryliak, Yu.V. Knyshenko, V. Durachenko, A.S. Dolinkevych","doi":"10.15407/itm2021.04.029","DOIUrl":"https://doi.org/10.15407/itm2021.04.029","url":null,"abstract":"The aim of this work is to analyze the state of the art in the development and use of pollution-free (“green”) propellants in low-thrust jet engines used as actuators of spacecraft stabilization and flight control systems and to adapt computational methods to the determination of “green”-propellant engine thrust characteristics. The monopropellant that is now widely used in the above-mentioned engines is hydrazine, whose decomposition produces a jet thrust due to the gaseous reaction products flowing out of a supersonic nozzle. Because of the high toxicity of hydrazine and the complex technology of hydrazine filling, it is important to search for its less toxic substitutes that would compare well with it in energy and mass characteristics. A promising line of this substitution is the use of ion liquids classed with “green” ones. The main components of these propellants are a water solution of an ion liquid and a fuel component. The exothermic thermocatalytic decomposition of a “green” propellant is combined with the combustion of its fuel component and increases the combustion chamber pressure due to the formation of gaseous products, which produces an engine thrust. It is well known that a “green” propellant itself and the products of its decomposition and combustion are far less toxic that hydrazine and the products of its decomposition, The paper presents data on foreign developments of “green” propellants of different types, which are under test in ground (bench) conditions and on a number of spacecraft. The key parameter that governs the efficiency of the jet propulsion system thrust characteristics is the performance of the decomposition and combustion products, which depends on their temperature and chemical composition. The use of equilibrium high-temperature process calculation methods for this purpose is too idealized and calls for experimental verification. Besides, a substantial contribution to the end effect is made by the design features of propellant feed and flow through a fine-dispersed catalyst layer aimed at maximizing the monopropellant-catalyst contact area. As a result, in addition to the computational determination of the thrust characteristics of a propulsion system under design, its experimental tryout is mandatory. The literature gives information on the performance data of “green”-propellant propulsion systems for single engines. However, in spacecraft control engine systems their number may amount to 8–16; in addition, they operate in different regimes and may differ in thrust/throttling characteristics, which leads to unstable propellant feed to operating engines. To predict these processes, the paper suggests a mathematical model developed at the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine and adapted to “green”-propellant engine systems. The model serves to calculate the operation of low-thrust jet engine systems and describes the propellant f","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"321 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132481748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas mass flow control in jet equipment","authors":"N. Pryadko, A. D. Yhnatev, H. Shevelova, K. Ternova","doi":"10.15407/itm2021.04.137","DOIUrl":"https://doi.org/10.15407/itm2021.04.137","url":null,"abstract":"Based on a numerical simulation of gas flows in an ejector unit and an analysis of grinding chamber acoustic signals, this paper shows ways to increase the efficiency of jet grinding. To prevent ejector speed-up tube wear and to obtain a ground product without impurities, the effect of feeding an additional energy carrier flow on the flow pattern in the speed-up tube of a jet mill was studied. A comparative analysis of the ejector flow pattern as a function of the presence of an additional feed and the speed-up tube shape was carried out. It was shown that the use of a conical nozzle offers a more uniform flow at the ejector outlet. The additional energy carrier feed provides a uniform increase in flow speed and reduces speed-up tube wall wear. The acoustic signals of the mill working zones were related to the jet grinding process parameters, around which a ground product quality control method was developed. The paper presents a technique for determining the material particle size in the energy carrier flow from the results of acoustic monitoring of the process. The technique uses the established relationship between the dispersion of the acoustic signal characteristic frequency and the mass of the corresponding fracture of the mixture in in-flow material transportation. The technique speeds up material particle size determination and improves the finished product quality. An automatic system was developed to control the grinding process by controlling the loading process according to the characteristics of the grinding zone acoustic signals. An operating model of a controlled hopper of a gas jet mill was made. The operability of the control system was verified on a simulation model, which includes a control objet (mill) model and a control system model. It was shown that the system of mill loading automatic control by the characteristics of the grinding zone acoustic signals offers an up to 10 percent increase in mill capacity, which was verified in industrial conditions at Vilnohorsk Mining and Metallurgical Plant.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122627638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of centrifugal deployment of three-section minisatellite boom","authors":"S. Khoroshylov, V.K. Shamakhanov, V. Vasyliev","doi":"10.15407/itm2021.04.056","DOIUrl":"https://doi.org/10.15407/itm2021.04.056","url":null,"abstract":"The aim of the article is to model the processes of centrifugal deployment of a three-section boom and preliminary analyze the feasibility of this deployment method for an Earth remote sensing (ERS) minisatellite (MS). During the research, methods of theoretical mechanics, multibody dynamics, control theory, and computer modeling were used. Centrifugal deployment of multi-section booms have been successfully used on spin stabilized satellites, but not on ERS satellites, which have other features of operation and require additional studies. The main part of the MS is a platform to which a transformable antenna is attached by means of a transformable boom. Before deployment, the stowed boom and antenna are attached to the MS platform. The boom sections are connected by joints with one rotational degree of freedom and deployed sequentially due to centrifugal forces when the MS rotates in the required direction. Each of the boom joints has a locking mechanism that latches when a predetermined deploy angle is reached. To model the processes of the boom deployment, the MS is presented as a system of connected bodies, where the platform and the stowed antenna are absolutely rigid bodies, and the boom consists of three flexible beams of a tubular cross-section. The differential equations of the MS dynamics during the deployment are obtained using the Lagrangian formalism, which are supplemented by algebraic equations describing the constraints from the joints. The scenarios of the boom deployment with a constant control torque and a constant angular velocity of the MS are considered. These scenarios are simulated, and estimates of the control actions needed to ensure full deployment of the boom and the stabilization of the MS after latching of the joints are calculated. Dependences of variations of the loads on the boom structure during deployment are obtained. The simulation results allow us to conclude that it is feasible to implement the method of the boom centrifugal deployment for the MS, which can perform fast rotations about the three axes of the body reference frame. Implementation of this method allows designers to reduce mass of the MS because it does not require any servo drives in the boom deployment system.","PeriodicalId":287730,"journal":{"name":"Technical mechanics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130511577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}