75504 2712-8172 Magazine of Civil Engineering 5 49 2014 1-145
RAR RUS 5-14 6602444316 LLC Research and Production Company “SCAD Soft” Perelmuter Anatoliy avp@scadsoft.com
Kiev, Ukraine
 Poltava National Technical Yuri Kondratiuk University Pichugin Sergii pichugin.sf@gmail.com Issues on estimation of building structure vulnerability The development of probabilistic methods of computation for building structures has mainly been aimed at improving the computation methodology. The attention was given to the accumulation of actual data as well to the research of statistical properties of influence and parameters of strength. However, it is necessary to mention that hardly ever new investigations have been done in the sphere of probabilistic evaluation. The priority attention was paid to the first ultimate state. The problems of structure reliability should not be restricted to the structure durability and stability estimation, and not all possible structure failures can be analyzed with probabilistic methods. It is reasonable to develop some original approaches to probabilistic reliability estimation. One important fact should be taken into account; it is the risk of structure vulnerability and a lack of statistical data for its estimation. It is sensible to evaluate both durability and longevity to prevent outer-boundary vulnerability all along the structure. In order to solve this problem, a new characteristic (mobilization of structure) and its definition are given. The paper presents some considerations and common examples to justify this method. The authors consider this issue to be polemic and ready to cause further professional discussion. 10.5862/MCE.49.1 random load outliers; reliability vulnerability https://engstroy.spbstu.ru/article/2014.49.1/ 01.pdf
RAR RUS 15-26 National Research Moscow State University of Civil Engineering Kabantsev Oleg ovk531@gmail.com
Moscow, Russia
 National Research Moscow State Civil Engineering University Tamrazyan Ashot tamrazian@mail.ru Allowing for changes in the calculated scheme during the analysis of structural behaviour Traditional calculation technologies are based on substantial simplifications and do not allow for very important (and in certain cases - crucial) situations related to changes in the design model during the life cycle of a building. The objective of the study was to analyze the processes that lead to changes in the structural design scheme, and to determine general principles of modeling changes in the design model. The study determined a set of basic elementary operations that allow modeling a step change in the design model. The paper presents the analysis of building up the model, and emphasizes the necessity to modify original geometrical parameters of the design scheme elements. The paper formulates modeling principles, presents theoretical foundations and principles of the calculation technology which tracks phase changes of the stress-and-strain state allowing for changes in the design scheme. The article comes up with proposals to implement the computational analysis during the structural degradation for different reasons (wear, corrosion, micro-and macro-fracture under load etc.). The research results can be applied in the analysis of building systems, separate designs and test samples in order to allow adequately for changes in the design scheme. 10.5862/MCE.49.2 design modeling load-bearing structures stress-and-strain state design prediction model of external constraints calculated technology exposure model https://engstroy.spbstu.ru/article/2014.49.2/ 02.pdf
RAR RUS 27-36 Tadeusz Kościuszko Cracow University of Technology Fialko Sergey sfialko@riad.pk.edu.pl Quadrilateral shell finite element for analysis of thin-walled reinforced concrete structures The paper presents the quadrilateral finite element for analysis of thin-walled reinforced concrete structures. The deformation theory of plasticity, formulated in terms of residual strains, is applied for behavior simulation of the both: concrete and steel. Such an approach allows us to simulate a cyclic loading as well as a dynamic one. The stress – strain diagram, proposed by the European Committee on concrete, is used for the compressed zone of concrete. The degradation, caused by the formation of cracks in the tensile zone, is described by the descending branch of the diagram. The symmetric stress-strain diagram, or its exponential approximation, is applied for steel. The compatibility of strains for concrete and steel is adopted. Reinforcements of the given direction are considered as a layer, which works only for compression-tension in this direction. The reinforcements of each direction are presented as a separate layer. We allow for the discrete placement of rods over thickness of the cross section. The Mindlin - Reissner shell theory is used for the reduction of a 3D problem to a 2D one; and the mixed interpolation of shear tensorial components is applied to overcome a shear locking effect. 10.5862/MCE.49.3 finite element method deformation theory of plasticity reinforced concrete principle of virtual work cyclic loading residual strains https://engstroy.spbstu.ru/article/2014.49.3/ 03.pdf
RAR RUS 37-43 H-9967-2013 16412815600 0000-0002-8588-3871 National Research University "Moscow Power Engineering Institute" Kirsanov Mikhail mpei2004@yandex.ru
14, Krasnokazarmennaya, 111250 Moscow, Russia
 Bending, torsion and asymptotic analysis of the cantilever bar The paper estimates deformation of elastic, statically determinate cantilever truss of the large internal volume which is subjected to bending and torsional loads for an arbitrary number of structure zones. The volume is increased by replacing flat sides of the truss with raised ones. Forces in the bars are determined analytically by cutting nodes of the truss. We derive simple analytical expressions for deflection, which allows selecting the optimal size and asymptotically compare the design flexibility to the known systems. It is shown that the flexibility of the proposed design is comparable with the known systems. Graphs, showing the dependence of the deflection on the size and the number of zones, reveal extremes, which enables optimizing the geometry of the truss. We have derived the accurate formulas for optimal parameters of the truss deflection. The induction method, supported by Maple mathematics software, is used. 10.5862/MCE.49.4 deformation induction method space truss cantilever; torsion https://engstroy.spbstu.ru/article/2014.49.4/ 04.pdf
RAR RUS 44-53 Moscow State University of Civil Engineering Tusnin Alexandr valeksol@mail.ru
Moscow, Russia
 Moscow State Civil Engineering University Prokic Milan prokic@mail.ru Behavior of symmetric steel I-sections under combined bending and torsion actions allowing for plastic deformations In steel structures, the combination of both a bending moment and bimoment actions on I-beam members is possible in many cases. In the elastic stage of work, the material bearing capacity check is based on maximum normal stresses, which for symmetric I-beams are the sum of moment and bimoment stresses. The maximum stresses are compared with the calculated resistance. With the development of plastic strains, the bearing capacity of the section is higher than in the elastic stage. The article examines the combined effect of a bending moment and bimoment on I-beams. The paper presents recommendations to check the I-beam bearing capacity, taking into account the development of plastic deformations. 10.5862/MCE.49.5 warping torsion I-beam bending moment bimoment plastic shape coefficient https://engstroy.spbstu.ru/article/2014.49.5/ 05.pdf
RAR RUS 54-62 Ufa State Petroleum Technological University Porivaev Ilya iporivaev@gmail.com Ufa State Petroleum Technological University Safiullin Marat safiullinmarat@list.ru Ufa State Petroleum Technological University Semenov Alexander asfugntu@yandex.ru
1, Kosmonavtov St., Ufa, Russia
 LLC, Scientific and Production Company “SCAD Soft Malyarenko Anatoliy maa@scadsoft.ru Stress-strain behavior investigation of friction grip bolts in flange joints of trusses This article presents the results of the numerical research on bolted flange joints in the field joint of trusses. A computational model was chosen for SCAD. The geometrically nonlinear calculation was made. The paper shows the correlation between stress and strain behavior of bolts and load intensity. Numerical results of the SCAD model calculation are compared with the results of the classical methods and ANSYS model calculation. The spatial stress-strain state of the connection is shown. The results of the study estimate the influence of bending moments on the stress-strain state of the bolts. The bending moments and rigidity ratio between different elements of the joints affect the load-carrying capacity of the bolts. The article is useful for engineers who are making calculations of tension flange joints. 10.5862/MCE.49.6 bolted flange joints finite element analysis analytical approach stress analysis https://engstroy.spbstu.ru/article/2014.49.6/ 06.pdf
RAR RUS 63-72 Novosibirsk State Technical Universit Salenko Sergey salenkosd@yandex.ru Novosibirsk State Technical University Gosteev Yuriy gosteev@corp.nstu.ru Novosibirsk State Technical University Obuhovskiy Aleksandr agd@craft.nstu.ru Influence of the shape on aerodynamic characteristics of girder bridges For accurate calculation of wind loads and prevention of aeroelastic superstructure vibrations it is necessary to research aerodynamic characteristics (ADF) of both particular designed bridges and typical superstructure sections. The analysis of information on the issue showed that the impact of the crosssectional shape on ADF of a bridge needs additional research. The object of the study was typical cross-sections of girder bridge superstructures. The research program included a wind tunnel and numerical calculations of the flow over 30 standard configurations in laminar and turbulent wind flows. The research resulted into the development of the database of aerodynamic data for estimating wind loads and effects (divergence, flutter, vortex excitation of oscillations, galloping) on girder bridge spans, and for specifying standards allowing for the cross-sectional shape of the structure. 10.5862/MCE.49.7 bridge spans aerodynamic characteristics divergence flutter vortex excitation of oscillations galloping physical and mathematical simulation wind tunnel https://engstroy.spbstu.ru/article/2014.49.7/ 07.pdf
RAR RUS 73-82 S-1676-2017 6507460407 0000-0002-8907-7869 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Mirsaidov Mirziyod theormir@mail.ru
39, Kori Niyoziy St., Tashkent, Uzbekistan, 100000
 55586710000 0000-0002-6498-5043 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Sultanov Takhirjon tz-sultanov@mail.ru
Tashkent, Republic of Uzbekistan
 Assessment of stress-strain state of earth dams with allowance for non-linear strain of material and large strains The paper presents results of studies on the dynamic behavior and stress-strain state of high earth dams with allowance for non-linearly viscoelastic properties of soil, large strains and heterogeneous features of a structure. The studies consider the effect of non-linearly viscoelastic properties of soil, large strains, heterogeneous character of a structure and geometrical parameters of a structure on the change of the stress-strain state of earth dams in pre-resonant, resonant and post-resonant modes of structure oscillations. As a result, some mechanical effects, occurring with allowance for the discussed factors in a dynamic mode of the structure operation, have been revealed. Consideration of large strains and heterogeneity of the structure leads to strengthening a stress jump between heterogeneous parts of the structure; consideration of non-linearly viscoelastic properties of the structure material in a resonant mode of oscillations decreases singnificantly the amplitude of displacements and amplitudes of stress intensity in dangerous (related to strength) points of a dam, comparing with a linearly elastic case. 10.5862/MCE.49.8 earth dams large strains non-linear viscoelasticity heterogeneity resonance stress-strain state dynamic behavior https://engstroy.spbstu.ru/article/2014.49.8/ 08.pdf
RAR RUS 83-94 6506522453 0000-0001-8114-1187 Tashkent Financial Institute Abdikarimov Rustamkhan rabdikarimov@mail.ru
60A, A.Temur street, Tashkent city, 100000
 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers Khodzhaev Dadakhan khodzhaevda@mail.ru Computer modeling of tasks in dynamics of viscoelastic thinwalled elements in structures of variable thickness The paper presents a numerical method and algorithm for solving tasks in dynamics of viscoelastic thin-walled elements in structures of variable thickness. The equations of motion concerning deflections are described by partial integro-differential equations (PIDE). Using Bubnov-Galerkin’s method, based on the polynomial approximation of deflections, the task is limited to the study of the system of ordinary IDEs, where the independent variable is time. The solution to the system of IDEs is obtained by the offered numerical method, which results into the algorithm of the numerical solution and the program in the Delphi algorithmic language. The study of nonlinear vibrations of thin-walled elements in structures, allowing for variable thickness in the geometrical nonlinear statement, has enabled revealing a number of mechanical effects. Depending on physico-mechanical and geometrical parameters of the considered viscoelastic thinwalled elements in structures, the authors reccommend how to use the rigidity of the system. 10.5862/MCE.49.9 thin-walled structures variable thickness viscoelasticity heterogeneity Bubnov-Galerkin’s method integro-differential equations https://engstroy.spbstu.ru/article/2014.49.9/ 09.pdf
RAR RUS 95-106 Peter the Great Saint Petersburg Polytechnic University Semenov Sergey ssgrus@gmail.com
Polytechnicheskay, 29
 6701751705 0000-0002-7889-1996 Peter the Great Saint Petersburg Polytechnic University Boris Melnikov kafedra@ksm.spbstu.ru
Polytechnicheskay, 29
 Peter the Great St. Petersburg Polytechnic University Grishchenko Alexei gai-gr@yandex.ru
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
 Dresden University of Technology Semenov Artem Semenov.Artem@googlemail.com Influence of structural parameters of the masonry on effective elastic properties and strength Two phase masonry model, which contains elastic mortar and elastic bricks, is analyzed numerically in order to evaluate sensitivity of effective elastic moduli and strength properties to a deviation in the masonry structural parameters. Different methods of masonry homogenization are studied. Effective elastic moduli of the masonry representative volume element are obtained by means of direct finite element simulation and homogenization procedure. Influence of variation in the heterogeneous material microstructure characteristics (influence of brick aspect ratio and orientation angle) on the local stress-strain state and mechanical properties of the representative volume element of the composite considered is analyzed. Mechanical properties obtained by direct finite element modeling and other methods in various literary sources are compared. These studies are relevant for the design of composite materials with a structure similar to masonry. 10.5862/MCE.49.10 masonry composite materials representative volume element homogenization numerical experiment boundary conditions of periodicity effective elastic moduli finite element method PANTOCRATOR https://engstroy.spbstu.ru/article/2014.49.10/ 10.pdf
RAR RUS 107-120 Tampere University of Technology Heinisuo Markku markku.heinisuo@tut.fi
Tampere, Finland
 Tampere University of Technology Jokinen Timo timo.jokinen@tut.fi
Tampere, Finland
 Tubular composite columns in a non-symmetrical fire A considerable number of studies have been conducted worldwide on fires that act on all four sides of a column (symmetrical fire). These cases are used for the validation of the analysis models developed in this study. In real buildings the columns are often embedded. If the fire does not act similarly on all surfaces of the column (non-symmetrical fire), it is extremely difficult to predict how the column will behave. The key research questions are: Is resistance stronger in non-symmetrical than in symmetrical fires? What is the final buckling mode, towards the fire or in the opposite direction? Results of numerical analyses for reinforced concrete filled square steel tube columns in nonsymmetrical fires are presented for a total of 150 cases. An ISO 834 fire acts constant along the column on one, two adjacent or three sides. Three embedding systems are considered for the remaining sides: adiabatic, concrete wall and sandwich panel. The material models are done using the Eurocodes and an initial bow imperfection is considered. The reference cases are symmetrical cases. When fire acted on one, two adjacent or three sides, the fire resistance times were on average about 3.4, 2 and 1.3 times longer than in a symmetrical fire. A concrete wall is a good thermal sink for columns. Slender columns typically buckle towards the fire. The final failure mode and corresponding resistance time depend on the direction of the initial bow imperfection. Experimental tests are needed to verify the results. 10.5862/MCE.49.11 fire resistance concrete filled steel tube column non-symmetrical fire finite element analysis Eurocode https://engstroy.spbstu.ru/article/2014.49.11/ 11.pdf