1.029
2712-8172
Magazine of Civil Engineering
1
53
2015
1-116
RAR
RUS
6-14
6602444316
Perelmuter
Anatoliy
LLC Research and Production Company “SCAD Soft”
avp@scadsoft.com
Kiev, Ukraine
Kabantsev
Oleg
National Research Moscow State University of Civil Engineering
ovk531@gmail.com
Moscow, Russia
Accounting for the elements stiffness change in the course of erection and operation
The problem statement related to modification of structural design model, when stiffness parameters of the structural members undergo changes, was considered. Some data was outlined from the design practice concerning design cases that occur during erection and maintenance of buildings and structures, when stiffness parameters of some structural members undergo changes. A physical mechanism that controls changing of these parameters was described for some of the design cases. Likewise, attention was paid to the design cases when changing of stiffness parameters has no relation to changing of actual stress-and-strain state and when such change occurs. Appropriate analysis methods were described.
10.5862/MCE.53.1
modeling
load-carrying structures
stress-and-strain state
design prediction
calculation technique
design model
model of external constraints
action model
https://engstroy.spbstu.ru/article/2015.53.1/
01.pdf
RAR
RUS
15-23
Utkin
Vladimir
Vologda State University
UtkinVoGTU@mail.ru
Vologda, Russia
Determination of residual load-bearing capacity of concrete beams at the operation stage by the strength reinforcement and concrete criterion
An experimental theoretical method was considered for estimating the residual load-bearing capacity of an individual reinforced concrete beam at the operational stage according to the criteria of the working strength and durability of concrete reinforcement compressed zone of the beam. Integrated methods of beam testing and probabilistic methods of random variables definition were used. Ultimate load in the form of interval during the operational phase was accepted as the measure of carrying capacity, discussion is presented on the choice of its value obtained from the interval boundary that has been obtained. Transition from the experimentally obtained value of the ultimate load to the maximum operational load was studied. Examples of design models of beams with operational load and guidelines on how to determine their limit values were given.
10.5862/MCE.53.2
bearing capacity of reinforced concrete beam
the strength of reinforcement
concrete strength
ultimate load
the design scheme
https://engstroy.spbstu.ru/article/2015.53.2/
02.pdf
RAR
RUS
24-31
Tusnin
Alexandr
Moscow State University of Civil Engineering
valeksol@mail.ru
Moscow, Russia
Prokic
Milan
Moscow State Civil Engineering University
prokic@mail.ru
Experimental research of I-beams under bending and torsion actions
The article presents the results of the theoretical and experimental research of I-beam behavior under combined bending and torsion. The analysis of numerical models was carried out, including calculations in which the physical and geometrical nonlinearity was taken into account. Based on the calculations, the parameters of experimental models and the value of the applied loads were determined. The samples were tested under the bending and torsion actions up to moment the element lost its bearing capacity completely. The experimental results were compared to the theoretical and numerical calculations. Correspondence between theoretical and experimental results was established (as a rule, the difference does not exceed 15%). The accuracy of the applied numerical methods for the analysis of beams under bending and torsion with due consideration of plastic deformation development was confirmed, which allows using them for developing engineering methods of beam calculating.
10.5862/MCE.53.3
I-beam
warping torsion
bending
tests
numerical calculations
bearing capacity
https://engstroy.spbstu.ru/article/2015.53.3/
03.pdf
RAR
RUS
32-38
H-9967-2013
16412815600
0000-0002-8588-3871
Kirsanov
Mikhail
National Research University "Moscow Power Engineering Institute"
mpei2004@yandex.ru
14, Krasnokazarmennaya, 111250 Moscow, Russia
Deflection analysis of rectangular spatial coverage truss
An elastic spatial statically determinate truss of regular type, simulating the rectangular in plan coverage was considered. In the plane of the base the truss has two axes of symmetry. Four support structures (spherical hinge, cylindrical hinge and two vertical rods) are located at its corners. An analytic solution was found for forces in the rods of the truss. Using the Maxwell-Mohr’s formula, the dependence of the deflection of the center was discovered in the truss under the influence of the concentrated force. There are five parameters of the problem in this formula: three linear dimensions, and the numbers of hinges on its lateral sides. To determine the desired patterns by means of the computer mathematics system Maple the recursion task by two parameters was solved. It was shown that dependence of the deflection on the number of panels and height of the truss detects a minimum, allowing optimizing the size of the structure.
10.5862/MCE.53.4
deformation
method of induction
space truss; coverage
https://engstroy.spbstu.ru/article/2015.53.4/
04.pdf
RAR
RUS
39-55
56091980300
0000-0003-3850-424X
Lalin
Vladimir
Peter the Great St. Petersburg Polytechnic University
vllalin@yandex.ru
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
Beliaev
Mikhail
Peter the Great Saint Petersburg Polytechnic University
belyaev-m-o@yandex.ru
Polytechnicheskay, 29
Bending of geometrically nonlinear cantilever beam. Results obtained by Cosserat – Timoshenko and Kirchhoff’s rod theories
The problem of verification of different program suites for structural analysis has recently become an important component of the construction science. One of the most extensively used benchmark problem is a classical geometrically nonlinear problem of deflection of the cantilever beam of linear elastic material, under the action of external vertical concentrated load at the free end. In fact, the solution for Kirchhoff’s rod is used as an analytical result. This rod is inextensible and Kirchhoff’s rod theory disregards flexibility of the rod in tension and shear. But in modern program suites Cosserat-Timoshenko rod is often used because Cosserat-Timoshenko rod theory is a geometrically exact theory. It considers not only bending strain but also shear and tensile strain. This means that it is necessary to get a model solution for Cosserat – Timoshenko rod, which can be used for verification of different software suites. This paper presents solutions of the geometrically nonlinear problem obtained by Cosserat – Timoshenko and Kirchhoff’s rod theory with comparison of those results. The findings can be used as a benchmark problem for verification of software suites.
10.5862/MCE.53.5
Cosserat – Timoshenko rod theory
Kirchhoff’s rod theory
geometrically nonlinear rods
parameter differentiation method
benchmark problem
https://engstroy.spbstu.ru/article/2015.53.5/
05.pdf
RAR
RUS
56-69
Solovei
N.
Kyiv National University of Construction and Architecture
Krivenko
O.
Kyiv National University of Construction and Architecture
olakop@ukr.net
Malygina
O.
Kyiv National University of Construction and Architecture
oksalita@mail.ru
Finite element models for the analysis of nonlinear deformation of shells stepwise-variable thickness with holes, channels and cavities
The method of solving static problems of nonlinear deformation, buckling, and postbuckling behavior of thin elastic inhomogeneous shells is based on the geometrically nonlinear equations of the 3D thermoelasticity theory and use of the moment finite-element scheme. A unified model has been created based on the universal spatial finite element with additional variable parameters. The model considers the multilayer structure of a material and geometrical features of structural elements of an inhomogeneous shell: casing of varying thickness, ribs, cover plates, cavities, channels, holes and sharp bends of the mid-surface. In a number of the authors’ works the reliability of linear and nonlinear solutions for a wide class of inhomogeneous shells has been numerically justified by analyzing their convergence and comparing them with those obtained by other authors. This paper is devoted to the comparative analysis of finite-element models and results of calculation of thin elastic shells using the moment finite-element scheme, and LIRA and SCAD program complexes. The effect of different types of weakening on nonlinear deformation and buckling of shells was studied on the example of isotropic panels under uniform pressure.
10.5862/MCE.53.6
flexible shell
moment finite-element scheme
nonlinear deformation
buckling; stepwise-varying thickness
weakening
https://engstroy.spbstu.ru/article/2015.53.6/
06.pdf
RAR
RUS
70-79
Ivanov
Oleg
Volga State University of Technology
IvanovOG@volgatech.net
Shlychkov
Sergey
Volga State University of Technology
shlychkovsv@volgatech.net
Сomputation of prismatic shells in elastic medium
The paper presents a computation procedure of physically nonlinear prismatic shells with the sealed ends. It is known that plates reinforced by stiffening ribs and located in the elastic medium can be calculated in a similar way as uniform ones (without reinforcements). In this case the effect of edges on the stress-strained state of plate was calculated in the form of the elastic support by Winklerian model. Thus, contact with the elastic medium was simulated, the medium was assumed in the form of a single-layer base. Dependence between the intensities of stresses and strains was established as a cubic polynomial. Fundamental differential equations were derived on the basis of the energy method. Final equations were realized by the numerical method of Runge – Kutta. Computation of U-shaped shell was executed on the basis of the obtained equations. Evaluation of the influence of elastic medium and physical nonlinearity on the stress-strained state of lamellar system was represented.
10.5862/MCE.53.7
physical nonlinearity
plate systems
the elastic support
https://engstroy.spbstu.ru/article/2015.53.7/
07.pdf
RAR
RUS
80-90
Usarov
M.
Institute of Mechanics and Seysmic Stability of Structures
umakhamatali@mail.ru
Buckling of orthotropic plates with bimoments
The paper is dedicated to improvement of plate theory in order to take into account forces, moments and bimoments, generated by nonlinear law of displacement distribution in plate cross-sections. Integral correlations for defining forces, moments and bimoments were given. The developed bimoment plate theory is described with two independent two-dimensional systems with nine equations in each. On each edge of plate nine boundary conditions were set. The approach to building the bimoment theory is based on the Hook law, three-dimensional equations of elasticity and decomposition of displacements in Maclaurin series. As an example, the solution of the problem of thick orthotropic plate buckling under action of transverse harmonic sinusoidal load was described. Numerical results were obtained for displacement, force, moments, bimoments and stresses, accompanied by analysis.
10.5862/MCE.53.8
Hooke’s law
orthotropy
theory of elasticity
3D problem
thick plate
planar problem
force
moment
bimoment
bimoment theory
https://engstroy.spbstu.ru/article/2015.53.8/
08.pdf
RAR
RUS
91-96
Shirunov
G.
TEKTON Co. Ltd
guriyn@mail.ru
Method of initial functions in model of compression linearly deformable layered foundation under normal local load
The three-dimensional problem of the theory of elasticity related to isotropic layer compression by normal load, distributed on a limited area, is solved by the method of initial functions (MIF). The layer divided into separate sub layers with different elastic characteristics serves as a model of the multilayer foundation. A parallelepiped cut out from the infinite layer with dimensions much larger than those of the load area may be considered as an elastic half-space. A numerical-analytic solution was obtained by a specially designed program based on the symbolic computation system called Maple, in which the desired functions of the displacements are represented by a Fourier series. The problem of computational instability calculations inherent in MIF at high numbers of harmonics was solved by using representation of real numbers with sufficient length mantissa. The results were compared both with solutions of the classical theory of elasticity for elastic halfspace, stipulated in the guidelines for designing foundations, and with the finite element method solutions.
10.5862/MCE.53.9
theory of elasticity
elastic layer
elastic half-space
method of initial functions
numerical–analytical solution
finite element method
multilayer foundation
https://engstroy.spbstu.ru/article/2015.53.9/
09.pdf