Ошибка
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering
  • Ошибка при загрузке модулей:Can't create/write to file '/var/lib/mysql/tmp/#sql_bd4_0.MYI' (Errcode: 30) SQL=SELECT id, title, module, position, content, showtitle, control, params FROM jos_modules AS m LEFT JOIN jos_modules_menu AS mm ON mm.moduleid = m.id WHERE m.published = 1 AND m.access <= 0 AND m.client_id = 0 AND ( mm.menuid = 8 OR mm.menuid = 0 ) ORDER BY position, ordering

DESIGNING AND DETAILING OF BUILDING SYSTEMS. MECHANICS IN CIVIL ENGINEERING

Realization of a discrete-braced calculation model in flat finite elements

Вестник МГСУ 11/2013
  • Mamin Aleksandr Nikolaevich - Public stock company «Central Scientific-Research and Experimental-Design Institute of Industrial Buildings and Structures» Doctor of Technical Sciences, Professor, Head, Department IBC № 1, Public stock company «Central Scientific-Research and Experimental-Design Institute of Industrial Buildings and Structures», 46|/2, Dmitrovskoe shosse, Moscow, 127238, Russian Federation; Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript .
  • Kodysh Emil' Naumovich - Public stock company «Central Scientific-Research and Experimental-Design Institute of Industrial Buildings and Structures» Doctor of Technical Sciences, Professor, Chief Designer, Department IBC №1, Public stock company «Central Scientific-Research and Experimental-Design Institute of Industrial Buildings and Structures», 46|/2, Dmitrovskoe shosse, Moscow, 127238, Russian Federation; Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript .
  • Reutsu Aleksandr Viktorovich - Public stock company «Central Scientific-Research and Experimental-Design Institute of Industrial Buildings and Structures» Department IBC № 1, Public stock company «Central Scientific-Research and Experimental-Design Institute of Industrial Buildings and Structures», 46|/2, Dmitrovskoe shosse, Moscow, 127238, Russian Federation; Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript .

Страницы 58-69

In the article the finite elements were developed that allow to take into consideration the design features of structures and the specific deformation of reinforced concrete without complicating the design scheme. The results of flat structures calculation under different types of loading are presented.The flat finite elements, which are used today in most widespread software systems for the calculation of the majority of buildings and structures, have significant drawbacks due to the peculiarities of the finite element method computational model. The two major drawbacks are: first, stiffness characteristics are specified as for rectangular cross-section and, second, constant stiffness characteristics over the entire area of finite elements is presupposed.These drawbacks are particularly evident in the process of calculating reinforced concrete structures and they significantly complicate the support systems design of multi-storey buildings. The simplifications used by the calculators are dangerous, as it is practically impossible to evaluate the resulting inaccuracies.The calculation model of the finite element method can be represented as a collection of nodes connected in one system with the help of finite elements, which conditionally replace the corresponding parts of a structure.Elasticity theory problems are solved with the help of finite elements of the shells and spatial finite elements. Here the accuracy of the results increases with the increase in breakdown frequency, and one of the main criteria for evaluating the effectiveness of discrete models is their convergence: the worse is the convergence — the higher breakdown frequency is needed to achieve the required accuracy of homogeneous structures calculations.In order to consider the factors affecting the calculations accuracy without increasing the complexity of making the design scheme, it is advisable to arrange a more detailed structure discretization on the stage of developing computational model. This concept is implemented in the discrete-braced computational model, which supposes replacement of the structure sections by the discreet braces combined in nodal points. The main advantages of discrete-braced model are determined by the possibility of multilevel discretization of a structure, achieved in terms of geometrical dimensions and in terms of the direction of digital communication, components of the stressstrain state, stiffness characteristics of digital communications, variable along the longitudinal axis and changing layer by layer in cross section.The basic diagram of the discrete-braced model is: the calculated structure is conditionally replaced by a set of nodes located at the layout grid lines crossing and linked in pairs by the discrete braces, which limit the mutual displacement of the nodal points for all the considered degrees of freedom.The stiffness characteristics of braces are set independently for each brace and each type of deformation on the basis of geometrical and deformational characteristics of the construction sections replaced by braces.In order to determine these sections, conventional boundary lines are traced on the structure, that are located between the grid lines. It is believed that these lines demarcate the structure sections that influence the stiffness parameters of the neighboring connections of one direction. Thus each out-of-node structure point belongs simultaneously to two sections. Stress-strain state of the structure, stiffness characteristics of the braces along the X and Y axes are defined independently of one another. The distributed internal forces arising in front sections of the braces are brought to concentrated generalized forces transmitted through the nodes between the braces in both directions.In the general case, each node of the obtained flat system has six degrees of freedom — three linear and three angular. Generalized displacements inside connections are described by linear functions. Each connection resists six types of deformations — tension and compression, shear in plane of the structure, shear out of the plane, torsion, rotation (bending in plane) and bending out of the plane. In the process of braces deformation, the efforts relevant to deformations appear in them: axial force , two shear forces, torque and two bending moments, and the stress-strain states during deformation of braces in plane and out of plane of the structure are independent from one another.It is offered to determine stress-strain state of the obtained discrete braced-noded system using the method of shifts by means of composing and solving the system of 6n linear algebraic equations (n — the number of nodes ).The accuracy and convergence of the calculation results for discrete-braced model of structural homogeneous isotropic elements is not inferior, and in some cases exceeds the accuracy and convergence of the finite element method results. The use of discretebraced model provides additional opportunities, in particular for non-linear calculations of reinforced concrete structures, which can significantly simplify the numerical schemes used, and thus significantly reduce the calculation complexity.

DOI: 10.22227/1997-0935.2013.11.58-69

Библиографический список
  1. R.E. Miller. Reduction of the Error in Eccentric Beam Modeling. International Journal for Numerical Methods in Engineering. 1980, vol. 15, no. 4, pp. 575—582.
  2. Chupin V.V. Razrabotka metodov, algoritmov, rascheta plastin, obolochek i mekhanicheskikh sistem, primenyaemykh v stroitel'stve i mashinostroenii [Development of Methods, Algorithms, Calculation of Slabs, Shells and Mechanical Systems Used in Construction and Mechanical Engineering]. Sbornik referatov nauchno-issledovatel'skikh i opytno-konstruktorskikh rabot. Seriya 16: 30. Mekhanika [Collection of Scientific, Research and Development Works. Series 16: 30. Mechanics]. 2007, no. 5, p. 146.
  3. Mamin A.N. Primenenie metoda peremeshcheniy dlya rascheta zhelezobetonnykh konstruktsiy zdaniy po diskretno-svyazevoy raschetnoy modeli [Using Shifting Method for Calculating Reinforced Concrete Building Structures with the Help of Discrete-Braced Calculation Model]. Sovershenstvovanie arkhitekturno-stroitel'nykh resheniy predpriyatiy, zdaniy i sooruzheniy: sbornik nauchnykh trudov TsNIIpromzdaniy [Development of Architectural and Construction Decisions of Enterprises, Buildings and Structures: Collection of Scientific Works of the Central Scientific and Research Institute of Industrial Buildings]. Moscow, 2006, pp. 78—82.
  4. Kodysh Je.N., Mamin A.N., Dolgova T.B. Raschetnaya model' dlya proektirovaniya nesushchnykh sistem i elementov [Calculation Model for Designing Bearing Systems and Elements]. Zhilishhnoe stroitel'stvo [House Construction]. 2003, no.11, pp. 9—15.
  5. Shan Tang, Adrian M. Kopacz, Stephanie Chan O’Keeffe, Gregory B. Olson, Wing Kam Liu. Concurrent Multiresolution Finite Element: Formulation and Algorithmic Aspects. Computational Mechanics. 2013, vol. 52, no. 6, pp. 1265-1279.
  6. Popov O.N., Radchenko A.V. Nelineynye zadachi rascheta pologikh obolochek i plastin s razryvnymi parametrami [Non-linear Tasks of Shallow Shells and Slabs Calculation with Diffuse Parameters]. Mekhanika kompozitsionnykh materialov i konstruktsiy [Mechanics of Composite Materials and Structures]. 2004, vol. 10, no. 4, pp. 545—565.
  7. Kiselev A.P., Gureeva N.A., Kiseleva R.Z. Raschet mnogosloynykh obolochek vrashcheniya i plastin s ispol'zovaniem ob"emnykh konechnykh elementov [Calculation of Multi-layer Rotational Shells and Slabs Using Solid Finite Elements]. Izvestiya vysshikh uchebnykh zavedeniy. Stroitel'stvo [News of Institutions of Higher Education. Construction]. 2010, no. 1, pp. 106—112.
  8. Spacone E., El-Tawil S. Nonlinear Analysis of Steel–concrete Composite Structures: State of the Art. Journal of Structural Engineering. 2004, no. 130 (2), pp. 159—168.
  9. Kodysh E.N., Mamin A.N. Primenenie metoda diskretnykh svyazey dlya rascheta zhelezobetonnykh konstruktsiy mnogoetazhnykh zdaniy [Using Discrete Braced Method for Reinforced Concrete Structures Calculation of Multi-storeyed Buildings]. Naukovo-tekhnichni problemi suchasnogo zalizobetonu: sbornik nauchykh trudov [Scientific and Technical Problems of Modern Reinforced Concrete: Collection of Scientific Works]. Kiev, NDIBK Publ., 2005, pp. 159—164.
  10. Verifikatsionnyy otchet po programmnomu kompleksu MicroFe [Verificational Report on the Software MicroFe]. Moscow, RAASN Publ., 2009, 327 p.
  11. Alessandro Zona, Gianluca Ranzi. Finite Element Models for Nonlinear Analysis of Steel–concrete Composite Beams with Partial Interaction in Combined Bending and Shear. Finite Elements in Analysis and Design. 2011, vol. 47, no. 2, pp. 98—118.
  12. H. Panayirci, H. Pradlwarter, G. Schu?ller. Efficient Stochastic Finite Element Analysis Using Guyan Reduction. Software. 2010, no. 41 (412), pp. 1277—1286.
  13. Manakhov P.V., Fedoseev O.B. Ob al'ternativnom metode vychisleniya nakoplennoy plasticheskoy deformatsii v zadachakh plastichnosti s ispol'zovaniem MKE [On the Alternative Method of Calculating Cumulative Plastic Flow in the Plasticity Tasks Using FEM]. Izvestiya vysshikh uchebnykh zavedeniy. Mashinostroenie [News of Institutions of Higher Education. Construction]. 2007, no. 7, pp. 16—22.
  14. Chen S., Shi X. Shear Bond Failure in Composite Slabs — a Detailed Experimental Study. Steel and Composite Structures. 2011, vol. 11, no.3, pp. 233—250.
  15. Eldib M., Maaly H., Beshay A., Tolba M. Modelling and Analysis of Two-way Composite Slabs. Journal of Constructional Steel Research. 2009, vol. 65, no.5, pp. 1236—1248.

Cкачать на языке оригинала

Результаты 1 - 1 из 1