Pub Date : 2022-07-05DOI: 10.24937/2542-2324-2022-3-401-52-57
A. V. Troitskiy, O. Kontievskaya
Object and purpose of research. The object of the study is compact lamellar resonating vibration absorbers (RVA). The purpose of the study is to develop a method for calculation of the dynamic strength of RVA, designed to assess the possibility of their use in ship shafting systems. Materials and methods. The initial data and material for the study were the design of a plate-shaped resonating vibration absorber and the amplitude value of the variable components of the forces accompanying the bending vibration of the shaft line. Simplified methods for calculating the dynamics and strength of plates during their deformation in the elastic region are applied. Main results. Developed method for calculation of dynamic strength of RVA. Relations are obtained that make it possible to choose the geometric dimensions of the RVA that ensure its dynamic strength and vibration damping efficiency. Conclusion. The possibility of ensuring the vibration resistance of the RVA designed to dampen the vibration of the shaft span is confirmed with the initial data accepted in the problem.
{"title":"Dynamic strength compact resonating vibration absorbers in the conditions of their application in ship shafting system","authors":"A. V. Troitskiy, O. Kontievskaya","doi":"10.24937/2542-2324-2022-3-401-52-57","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-3-401-52-57","url":null,"abstract":"Object and purpose of research. The object of the study is compact lamellar resonating vibration absorbers (RVA). The purpose of the study is to develop a method for calculation of the dynamic strength of RVA, designed to assess the possibility of their use in ship shafting systems. Materials and methods. The initial data and material for the study were the design of a plate-shaped resonating vibration absorber and the amplitude value of the variable components of the forces accompanying the bending vibration of the shaft line. Simplified methods for calculating the dynamics and strength of plates during their deformation in the elastic region are applied. Main results. Developed method for calculation of dynamic strength of RVA. Relations are obtained that make it possible to choose the geometric dimensions of the RVA that ensure its dynamic strength and vibration damping efficiency. Conclusion. The possibility of ensuring the vibration resistance of the RVA designed to dampen the vibration of the shaft span is confirmed with the initial data accepted in the problem.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42017618","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}
Pub Date : 2022-07-05DOI: 10.24937/2542-2324-2022-3-401-58-70
B. Yartsev, V. Ryabov, L. Parshina
Object and purpose of research. The study is concerned with a three-layer plate formed by two rigid anisotropic layers and a soft medium isotropic layer of viscoelastic polymer. Each rigid layer presents anisotropic structure formed by a finite number of randomly oriented orthotropic viscoelastic layers of composites. The paper is intended to study the influence of reinforcement orientation of rigid layers, relative thickness of the soft layer of an isotropic viscoelastic polymer and the ambient temperature on values values of natural frequencies and mechanical loss factors of the coupled damped oscillations in symmetric and assymetric plates. Materials and methods. Numerical experiment using a computer program implementing the previously proposed method for solving coupled differential equations of damped oscillations in anisotropic three-layer plates [2]. Main results. It was shown that in unsupported globally monoclinic symmetrical three-layer rectangular plate a bendingtorsional interaction occurs, generating mutual transformations of the eigenforms of the coupled oscillation modes if at least in one of the directions of the plate one of the eigenforms is characterized by an even number of quarters of the wave, and the other eigenform is characterized by an odd number of quarters of the wave. In unsupported globally orthotropic asymmetric three-layer rectangular plate interaction of bending modes of oscillations occurs in two mutually orthogonal planes, if both eigenforms are characterized by either an even or an odd number of wave quarters in main directions of the plate. It was found that each mode of natural oscillations of both symmetric and asymmetric three-layer plates has its own effective relative thickness of the soft layer of an isotropic viscoelastic polymer corresponding to the maximum level of dissipative properties. A further increase in the relative thickness is often accompanied by a decrease in values of the mechanical loss factors. The significant influence of ambient temperature on natural frequencies values and mechanical loss factors of all considered oscillation modes of symmetric and asymmetric unsupported rectangular three-layer composite plates is demonstrated. Conclusion. It was found that coupled damped oscillations of a symmetric three-layer plate are described by two systems of differential equations, with structures close to that of the systems of corresponding differential equations describing the damped oscillations of a quasi-homogeneous monoclinic plate. At the same time, the coupled damped oscillations of an asymmetric three-layer plate are described by two systems of differential equations that coincide with the systems of corresponding differrential equations describing the damped oscillations of a globally orthotropic three-layer plate.
{"title":"Dissipative properties of three-layered composite structures. 4. Numerical experiment","authors":"B. Yartsev, V. Ryabov, L. Parshina","doi":"10.24937/2542-2324-2022-3-401-58-70","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-3-401-58-70","url":null,"abstract":"Object and purpose of research. The study is concerned with a three-layer plate formed by two rigid anisotropic layers and a soft medium isotropic layer of viscoelastic polymer. Each rigid layer presents anisotropic structure formed by a finite number of randomly oriented orthotropic viscoelastic layers of composites. The paper is intended to study the influence of reinforcement orientation of rigid layers, relative thickness of the soft layer of an isotropic viscoelastic polymer and the ambient temperature on values values of natural frequencies and mechanical loss factors of the coupled damped oscillations in symmetric and assymetric plates. Materials and methods. Numerical experiment using a computer program implementing the previously proposed method for solving coupled differential equations of damped oscillations in anisotropic three-layer plates [2]. Main results. It was shown that in unsupported globally monoclinic symmetrical three-layer rectangular plate a bendingtorsional interaction occurs, generating mutual transformations of the eigenforms of the coupled oscillation modes if at least in one of the directions of the plate one of the eigenforms is characterized by an even number of quarters of the wave, and the other eigenform is characterized by an odd number of quarters of the wave. In unsupported globally orthotropic asymmetric three-layer rectangular plate interaction of bending modes of oscillations occurs in two mutually orthogonal planes, if both eigenforms are characterized by either an even or an odd number of wave quarters in main directions of the plate. It was found that each mode of natural oscillations of both symmetric and asymmetric three-layer plates has its own effective relative thickness of the soft layer of an isotropic viscoelastic polymer corresponding to the maximum level of dissipative properties. A further increase in the relative thickness is often accompanied by a decrease in values of the mechanical loss factors. The significant influence of ambient temperature on natural frequencies values and mechanical loss factors of all considered oscillation modes of symmetric and asymmetric unsupported rectangular three-layer composite plates is demonstrated. Conclusion. It was found that coupled damped oscillations of a symmetric three-layer plate are described by two systems of differential equations, with structures close to that of the systems of corresponding differential equations describing the damped oscillations of a quasi-homogeneous monoclinic plate. At the same time, the coupled damped oscillations of an asymmetric three-layer plate are described by two systems of differential equations that coincide with the systems of corresponding differrential equations describing the damped oscillations of a globally orthotropic three-layer plate.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41974272","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}
Pub Date : 2022-07-05DOI: 10.24937/2542-2324-2022-3-401-152-164
O. Savchenko, V. Polovinkin
Object and purpose of research. The object of the study is domestic shipbuilding, its problems and ways to solve them. The article is intended to study the current state of the Russian shipbuilding industry, to investigate the tasks of its further development and to formulate priority measures to stimulate this development. Materials and methods. The solution of the tasks set in the article was carried out on the basis of application of general scientific methods in the framework of comparative, logical and statistical analysis, study of literary sources in regards to the issue in consideration as well as through the study of structures of domestic shipbuilding industries, pricing methods, financial analysis, etc. The material is extensive statistical data on the production programs of shipbuilding yards. Main results. A study of the state of contemporary domestic shipbuilding has been carried out. The analysis of trends in the development of world shipbuilding at the turn of the century allowed us to identify the general directions that form the image of promising Russian shipbuilding technologies. It is concluded that the world level of development of technical and software tools, as well as communication tools, allows us to move to fundamentally new methods of design, construction and support of vessels and ships operation based on a single information space and providing information support for all stages of the ship's life cycle (information support of the life cycle, or CALS-technology). Conclusion. According to the conducted research of the shipbuilding market, the nomenclature and production volumes of Russian enterprises do not fully cover the existing needs of shipbuilding. However, the domestic shipbuilding industry has sufficient scientific, technical, production and technological potential and market capacity. Our manufacturers have every chance to take a leading position in commercial fleet construction segment in the near future, because the need for Russian-made components with technical and operational characteristics that are not inferior to foreign analogues will increase. Today favourable conditions are forming to stimulate the localization of production. At the same time, the key factors are the stability of Russian legislation and compliance with the obligations assumed by the state, which will ensure the attraction of long-term localization and indigenisation projects in general. The development of own production of a wide range in shipbuilding industry will allow the Russian Federation to pursue a selfsustained and independent policy aimed at ensuring the technological security of the country. To solve such a complex task, an integrated, systematic approach is needed, involving close cooperation between the state, business, and research institutes, which as a result will allow us to build an optimal program for the development of the entire industry.
{"title":"The current state, problems and prospects of domestic commercial shipbuilding","authors":"O. Savchenko, V. Polovinkin","doi":"10.24937/2542-2324-2022-3-401-152-164","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-3-401-152-164","url":null,"abstract":"Object and purpose of research. The object of the study is domestic shipbuilding, its problems and ways to solve them. The article is intended to study the current state of the Russian shipbuilding industry, to investigate the tasks of its further development and to formulate priority measures to stimulate this development. Materials and methods. The solution of the tasks set in the article was carried out on the basis of application of general scientific methods in the framework of comparative, logical and statistical analysis, study of literary sources in regards to the issue in consideration as well as through the study of structures of domestic shipbuilding industries, pricing methods, financial analysis, etc. The material is extensive statistical data on the production programs of shipbuilding yards. Main results. A study of the state of contemporary domestic shipbuilding has been carried out. The analysis of trends in the development of world shipbuilding at the turn of the century allowed us to identify the general directions that form the image of promising Russian shipbuilding technologies. It is concluded that the world level of development of technical and software tools, as well as communication tools, allows us to move to fundamentally new methods of design, construction and support of vessels and ships operation based on a single information space and providing information support for all stages of the ship's life cycle (information support of the life cycle, or CALS-technology). Conclusion. According to the conducted research of the shipbuilding market, the nomenclature and production volumes of Russian enterprises do not fully cover the existing needs of shipbuilding. However, the domestic shipbuilding industry has sufficient scientific, technical, production and technological potential and market capacity. Our manufacturers have every chance to take a leading position in commercial fleet construction segment in the near future, because the need for Russian-made components with technical and operational characteristics that are not inferior to foreign analogues will increase. Today favourable conditions are forming to stimulate the localization of production. At the same time, the key factors are the stability of Russian legislation and compliance with the obligations assumed by the state, which will ensure the attraction of long-term localization and indigenisation projects in general. The development of own production of a wide range in shipbuilding industry will allow the Russian Federation to pursue a selfsustained and independent policy aimed at ensuring the technological security of the country. To solve such a complex task, an integrated, systematic approach is needed, involving close cooperation between the state, business, and research institutes, which as a result will allow us to build an optimal program for the development of the entire industry.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46303345","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}
Pub Date : 2022-07-05DOI: 10.24937/2542-2324-2022-3-401-121-127
V. Kalyu, N. V. Krasnopistsev, G. I. Losev, V. Nekrasov, V.V. Petrova, D. Smirnov
Object and purpose of research. Moving broadband source underwater noise level estimations obtained by direct and indirect methods using a receiver for the measurement of sound pressure and sound particle velocity components combined. Materials and methods. Theoretical research using computer simulation, full-scale experiments in real measurement conditions, statistical analysis of experimental results. Main results. The noise level estimations obtained by the direct method, only through the sound pressure channel, and by the indirect method with recalculating the values of sound intensity were compared based on representative samples under ideal conditions and in real water area conditions. Conclusion. Under ideal measurement conditions a statistically significant difference between the two estimation methods occurs only at frequencies below 16 Hz. The results of a full-scale experiment in real conditions show that the estimate obtained on the basis of the spatial selective sound intensity vector is characterized by greater reliability and accuracy since it is less affected by reflections from the boundaries of the water area.
{"title":"Comparison of the results of measurements of the source underwater noise levels obtained by the direct method and using vector-phase processing","authors":"V. Kalyu, N. V. Krasnopistsev, G. I. Losev, V. Nekrasov, V.V. Petrova, D. Smirnov","doi":"10.24937/2542-2324-2022-3-401-121-127","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-3-401-121-127","url":null,"abstract":"Object and purpose of research. Moving broadband source underwater noise level estimations obtained by direct and indirect methods using a receiver for the measurement of sound pressure and sound particle velocity components combined. Materials and methods. Theoretical research using computer simulation, full-scale experiments in real measurement conditions, statistical analysis of experimental results. Main results. The noise level estimations obtained by the direct method, only through the sound pressure channel, and by the indirect method with recalculating the values of sound intensity were compared based on representative samples under ideal conditions and in real water area conditions. Conclusion. Under ideal measurement conditions a statistically significant difference between the two estimation methods occurs only at frequencies below 16 Hz. The results of a full-scale experiment in real conditions show that the estimate obtained on the basis of the spatial selective sound intensity vector is characterized by greater reliability and accuracy since it is less affected by reflections from the boundaries of the water area.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46913105","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}
Pub Date : 2022-05-16DOI: 10.24937/2542-2324-2022-2-400-40-50
P. Dodonov
Object and purpose of research. The object of research is a composite material of the syntactic foam type (SF), which forms a heterogeneous medium consisting of a polymer matrix filled with spherical inclusions- micro spheres. The paper suggests that distribution of micro spheres in SF should be used as a qualitative measure for estimation procedures. Comparison of such distribution for various models can be used for explaining the SF efficiency estimations. Materials and methods. The initial data inputs for the study were the composition and structure of syntactic foam and characteristics of its components: polymer matrix and glass micro spheres. Numerical studies were carried out using the earlier developed structural model of SF deformation and damage. The structural model assesses the stressed-strained state of large micro sphere assemblies (models with a number of spheres about 105 are used in the study). Results obtained by the model let us use statistical methods of processing the stress raisers and identify patterns of distributions for predicting the SF strength. The results are verified by comparison with estimations by finite element models. Main results. The structural model of deformation and damage is highly effective in calculation of the stressed-strained state of micro structures with a number of micro spheres of about 105 and more. Conclusion. The structural model developed for SF makes it possible to accurately assess the stresses of its components under external hydrostatic pressure considering a large number of micro spheres. The results show excellent convergence of the stressed-strained state estimates with detailed estimations by FE models. With accurate data on the stressed-strained state of micro structure one can predict how the damage would develop and calculate the process to failure and full loss of buoyance.
{"title":"Statistical approach to description of stressed state of syntactic foam microstructure","authors":"P. Dodonov","doi":"10.24937/2542-2324-2022-2-400-40-50","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-2-400-40-50","url":null,"abstract":"Object and purpose of research. The object of research is a composite material of the syntactic foam type (SF), which forms a heterogeneous medium consisting of a polymer matrix filled with spherical inclusions- micro spheres. The paper suggests that distribution of micro spheres in SF should be used as a qualitative measure for estimation procedures. Comparison of such distribution for various models can be used for explaining the SF efficiency estimations. Materials and methods. The initial data inputs for the study were the composition and structure of syntactic foam and characteristics of its components: polymer matrix and glass micro spheres. Numerical studies were carried out using the earlier developed structural model of SF deformation and damage. The structural model assesses the stressed-strained state of large micro sphere assemblies (models with a number of spheres about 105 are used in the study). Results obtained by the model let us use statistical methods of processing the stress raisers and identify patterns of distributions for predicting the SF strength. The results are verified by comparison with estimations by finite element models. Main results. The structural model of deformation and damage is highly effective in calculation of the stressed-strained state of micro structures with a number of micro spheres of about 105 and more. Conclusion. The structural model developed for SF makes it possible to accurately assess the stresses of its components under external hydrostatic pressure considering a large number of micro spheres. The results show excellent convergence of the stressed-strained state estimates with detailed estimations by FE models. With accurate data on the stressed-strained state of micro structure one can predict how the damage would develop and calculate the process to failure and full loss of buoyance.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45899265","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}
Pub Date : 2022-05-16DOI: 10.24937/2542-2324-2022-2-400-24-39
А.R. Filatov
Object and purpose of research. The object of research is marine engineering structures. The purpose is to assess the outlook for application of smooth particle hydrodynamics (SPH) for numerical modeling of ice loads. Materials and methods. For this purpose an overview of the most popular methods for numerical solution of problems in fracture mechanics is given with their merits and drawbacks (finite element method, extended finite element method, discrete element method, smooth particle hydrodynamics, smoothed particle Galerkin). Main SPH relations are presented. Main results. A test problem of a cylinder leg interacting with level ice field is used to obtain a qualitative pattern of ice deformation and failure with and without ice breaking arrangements, as well as under the global ice load. Conclusion. Analysis of obtained results shows that SPH in the sliding least square method formulation is promising for numerical modeling of plastic damage in fine grained ice and definition of corresponding loads on marine structures.
{"title":"Outlook for application of smooth particle hydrodynamics for numerical modeling of ice loads","authors":"А.R. Filatov","doi":"10.24937/2542-2324-2022-2-400-24-39","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-2-400-24-39","url":null,"abstract":"Object and purpose of research. The object of research is marine engineering structures. The purpose is to assess the outlook for application of smooth particle hydrodynamics (SPH) for numerical modeling of ice loads. Materials and methods. For this purpose an overview of the most popular methods for numerical solution of problems in fracture mechanics is given with their merits and drawbacks (finite element method, extended finite element method, discrete element method, smooth particle hydrodynamics, smoothed particle Galerkin). Main SPH relations are presented. Main results. A test problem of a cylinder leg interacting with level ice field is used to obtain a qualitative pattern of ice deformation and failure with and without ice breaking arrangements, as well as under the global ice load. Conclusion. Analysis of obtained results shows that SPH in the sliding least square method formulation is promising for numerical modeling of plastic damage in fine grained ice and definition of corresponding loads on marine structures.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47514811","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}
Pub Date : 2022-05-16DOI: 10.24937/2542-2324-2022-2-400-67-78
Biplabananda Talukdar
The paper primarily includes comparative performance analyses (i.e. changes/improvements in Resistance & Seakeeping characteristics) of a warship monohull (with a conventional bow), operating in displacement mode, when modified to various inverted bow forms. The work presented in the paper has been inspired by various research works already published worldwide and available literature regarding the same. For the research problem, a naval warship hull with conventional bow was taken as the benchmark and was suitably modified to a number of different hull form variants with inverted bow forms (i.e. Axe bow, Uistein X-bow, Sword bow and typical Inverted Bow forms), preserving sufficient characteristics for a meaningful comparison, yet making enough changes in various hull form parameters to obtain sufficient variations in hydrodynamic characteristics. Based on the analyses, it was possible to undertake multistage screening of the hull variants, as well as to obtain a considerable overview which enabled to make definitive comments regarding the research questions formulated.
{"title":"Comparative resistance & seakeeping analyses of warship displacement monohulls, when modified to inverted bow forms from conventional bow","authors":"Biplabananda Talukdar","doi":"10.24937/2542-2324-2022-2-400-67-78","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-2-400-67-78","url":null,"abstract":"The paper primarily includes comparative performance analyses (i.e. changes/improvements in Resistance & Seakeeping characteristics) of a warship monohull (with a conventional bow), operating in displacement mode, when modified to various inverted bow forms. The work presented in the paper has been inspired by various research works already published worldwide and available literature regarding the same. For the research problem, a naval warship hull with conventional bow was taken as the benchmark and was suitably modified to a number of different hull form variants with inverted bow forms (i.e. Axe bow, Uistein X-bow, Sword bow and typical Inverted Bow forms), preserving sufficient characteristics for a meaningful comparison, yet making enough changes in various hull form parameters to obtain sufficient variations in hydrodynamic characteristics. Based on the analyses, it was possible to undertake multistage screening of the hull variants, as well as to obtain a considerable overview which enabled to make definitive comments regarding the research questions formulated.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42580162","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}
Pub Date : 2022-05-16DOI: 10.24937/2542-2324-2022-2-400-79-88
М.Yu. Mironov
Object and purpose of research. The study focuses on management of dynamic parameters of structures, the load on which has unsteady character in accordance with a given frequency spectrum. Based on the earlier obtained [8, 15] matrix relations of sensitivity analysis, effective design iteration algorithms, which satisfy Kuhn–Tucker optimum conditions, are developed and implemented in software. Materials and methods. The methods used are a displacement method version of the beam finite-element technique, analytical and semi-analytical methods of taking a derivative with respect to frequencies, shapes as well as unsteady displacements of structure integrally averaged in space and time, methods of simple iterations with relaxation smoothening, methods of linearization of recurrent relations of optimality conditions and reduction of conditional minimization problem to unconditional problem using Lagrange factors. Main results. For FE beam model with a large number of finite elements, minimization mass problems are solved at restricted integral norm of deflection for various unsteady excitation at a given time interval. Comparison of optimization procedures are made for accuracy and efficiency using direct implicit differentiation of difference scheme and normal mode method for response. Conclusion. Similar results are obtained by different methods of calculating the unsteady response and performance of sensitivity analysis. Efficient management of the mass and stiffness distribution is demonstrated with a relatively high gain in isoperimetric formulation.
{"title":"Optimization of multi-element models of structures with integral constraints on unsteady responses","authors":"М.Yu. Mironov","doi":"10.24937/2542-2324-2022-2-400-79-88","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-2-400-79-88","url":null,"abstract":"Object and purpose of research. The study focuses on management of dynamic parameters of structures, the load on which has unsteady character in accordance with a given frequency spectrum. Based on the earlier obtained [8, 15] matrix relations of sensitivity analysis, effective design iteration algorithms, which satisfy Kuhn–Tucker optimum conditions, are developed and implemented in software. Materials and methods. The methods used are a displacement method version of the beam finite-element technique, analytical and semi-analytical methods of taking a derivative with respect to frequencies, shapes as well as unsteady displacements of structure integrally averaged in space and time, methods of simple iterations with relaxation smoothening, methods of linearization of recurrent relations of optimality conditions and reduction of conditional minimization problem to unconditional problem using Lagrange factors. Main results. For FE beam model with a large number of finite elements, minimization mass problems are solved at restricted integral norm of deflection for various unsteady excitation at a given time interval. Comparison of optimization procedures are made for accuracy and efficiency using direct implicit differentiation of difference scheme and normal mode method for response. Conclusion. Similar results are obtained by different methods of calculating the unsteady response and performance of sensitivity analysis. Efficient management of the mass and stiffness distribution is demonstrated with a relatively high gain in isoperimetric formulation.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48745845","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}
Pub Date : 2022-05-16DOI: 10.24937/2542-2324-2022-2-400-17-23
V. Korshunov, R. Mudrik, D. Ponomarev, А.А. Rodionov, М. Kuteinikov
Object and purpose of research. The study deals with the problem of defining the integral external loads on the ship hull by various methods with subsequent comparison of system responses. Materials and methods. For determination of external forces in regular waves the strip method and panel method are used based on the boundary element technique. Main results. Response amplitude operators (RAO) of bending moments and shearing forces for different wave headings obtained by various methods are compared. Calculation procedures are analyzed. Conclusion. The problem of defining the external forces on the ship hull was solved and numerical hydrodynamic procedures were analyzed in the work. Results show that both methods are practical, while the panel method provides a wider range of possibilities to input and include non-linear parameters.
{"title":"Comparative analysis of various models for predicting wave loads on ship hull","authors":"V. Korshunov, R. Mudrik, D. Ponomarev, А.А. Rodionov, М. Kuteinikov","doi":"10.24937/2542-2324-2022-2-400-17-23","DOIUrl":"https://doi.org/10.24937/2542-2324-2022-2-400-17-23","url":null,"abstract":"Object and purpose of research. The study deals with the problem of defining the integral external loads on the ship hull by various methods with subsequent comparison of system responses. Materials and methods. For determination of external forces in regular waves the strip method and panel method are used based on the boundary element technique. Main results. Response amplitude operators (RAO) of bending moments and shearing forces for different wave headings obtained by various methods are compared. Calculation procedures are analyzed. Conclusion. The problem of defining the external forces on the ship hull was solved and numerical hydrodynamic procedures were analyzed in the work. Results show that both methods are practical, while the panel method provides a wider range of possibilities to input and include non-linear parameters.","PeriodicalId":33210,"journal":{"name":"Trudy Krylovskogo gosudarstvennogo nauchnogo tsentra","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45203069","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}
Pub Date : 2022-05-16DOI: 10.24937/2542-2324-2022-2-400-99-102
V. V. Popov, V. Manukhin
Object and purpose of research. The paper is concerned with interaction of the docking stanchion and the transverse bulkhead plating when a ship is docked. Involvement of the bulkhead plating and vertical pillars closest to the docking stanchion in sustaining the response of the keel track is assessed. The purpose of the study is updating the classical design procedure for docking stanchion where such interaction is ignored. Materials and methods. A plane steel transverse bulkhead of traditional type is considered. Loads on a dry-docked ship are estimated. Finite element method is used. Main results. Studies were conducted using two finite element models: a 2D bulkhead model and a 3D model of ship hull part incorporating bulkhead. Results of calculation by both models are generally in good agreement. It is shown that along with the docking stanchion the keel track response is sustained partly by the bulkhead plating and vertical struts closest to the docking stanchion. Conclusion. The classical design method of docking stanchions was updated, which made it possible to reduce the weight and size of docking stanchions. The formula used to assess the buckling of docking stanchions was corrected.
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