No 3 (2014)
- Year: 2014
- Articles: 10
- URL: https://journals.rudn.ru/structural-mechanics/issue/view/687
Articles
REVIEW OF LIMIT LOAD AND SHAKEDOWN THEOREMS FOR THE ELASTIC-PLASTIC ANALYSIS OF STEEL STRUCTURES.
Abstract
A consistent set of theorems is presented in this paper which permits the determination of ultimate and shakedown loads of steel structures with small displacements by solving an optimization problem. The proofs of the theorems show that all theorems depend on the linear superposition of load cases to form load combinations. If the behavior of the structure becomes geometrically nonlinear because it is affected by large displacements, load cases can no longer be superimposed. New concepts are therefore required for the limit and shakedown analysis of structures with significant geometric nonlinearity.
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):3-18
3-18
FEATURES OF THE IMAGE OF PROCESS OF FORMATION OF SURFACES IN AUTOCAD SYSTEM
Abstract
The article considers the possibility of visualization of the process of formation of umbrella surfaces in the dynamic mode by creating a mini-film, which can be used as a lecturer at lec- tures or practical classes and students for self-study course «Computer graphics».
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):19-22
19-22
KINEMATIC RULED SURFACES ON THE BASE OF COMPLEX MOVING ONE AXOID ALONG ANOTHER (one-sheet hyperboloidal surface of revolution as fixed and moving axoids)
Abstract
Geometrical model of complex moving one-sheet hyperboloid of revolution along another as a base for generating new kinematic ruled surfaces is proposed. Both cases with one axoid's loca- tion outside another and one axoid's location in the interior of another are described. Analytical development and computer visualization of the new kinematic ruled surfaces are realized.
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):23-31
23-31
INVERSE PROBLEM OF THE THEORY OF BENDING OF THE PLATE WITH INCLUSIONS
Abstract
He criterion and method of the solution of a problem of the theory of a bending of thin plates on decrease in concentration of stresses in a composite plate is given by optimization of the form of border of connection of various elastic materials.
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):32-36
32-36
ESTIMATION OF DYNAMIC RESPONSES ON CONTOURS OF SEVERAL ROUND CUTS AT VIBRATIONS OF A THIN PLATE
Abstract
In accordance with the wave model vertical vibrations of a thin plate with one or more circular cuts are considered. Analytical expressions for the dynamic stiffness taking into ac- count the distance between the circular piles at vertical vibration are defined. The obtained results allow us to refine the values of amplitude and frequency characteristics of pile founda- tions under dynamic loads
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):37-43
37-43
NUCLEATION OF CRACKS IN ISOTROPIC MEDIUM WITH PERIODIC SYSTEM OF THE CIRCULAR HOLES FILLED WITH RIGID INCLUSIONS, AT LONGITUDINAL SHEAR
Abstract
The model of nucleation of cracks in composites with the periodic structure, based on consideration of a zone of process fracturing is offered. It is necessary, that the zone of process fracturing represents a layer of the finite length containing a material with in part broken bonds between separate structural elements. Presence of bonds between faces of prefracture zones (a zone of the weakened interparticle bonds of a material) is modelled by applying to a surface of prefracture zones of caused by of bonds cohesive forces. The analysis of limiting balance of a prefracture zones at longitudinal shear is carried out on the basis of criterion of limiting shear of bonds of a material and includes: 1) an establishment of dependence of cohe- sive forces from shear of faces of a prefracture zones; 2) an estimation of an intense condition near to a prefracture zones in view of external loadings and cohesive forces and also an ar- rangement of rigid inclusions; 3) definition of the dependence of critical external loadings from geometrical parameters of the compound environment at which there is a crack.
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):44-50
44-50
DIRECT ELASTIC-PLASTIC LIMIT LOAD AND SHAKEDOWN ANALYSIS OF STEEL SPACE TRUSSES WITH LARGE DISPLACEMENTS
Abstract
A direct method for elastic-plastic limit load and shakedown analysis of steel space trusses with large displacements is treated in this paper. The incremental method for the geometrically nonlinear analysis of space trusses, developed by one of the authors was modified to account for yielding and plastic strains in the bars of the truss. The new method has been implemented in computer software. The examples in this paper show that the direct analysis of space trusses with large displacements can be implemented successfully for both the limit and the shakedown analysis of space trusses on the Java platform. The algorithms cover a wide range of elastic-plastic truss behavior: purely elastic behavior, shakedown, ratcheting and collapse due to the formation of a mechanism. The sequence in which the bars yield, the load levels at which this occurs, the accumulation of the plastic strains in the bars, the residual stresses in the bars and the node displacements during ratcheting can all be evaluated. The computer application is therefore suitable as a test platform for elastic-plastic truss behavior. It can be applied to many other problems of elastic-plastic space truss analysis
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):51-64
51-64
65-70
ON THE RELIABILITY OF RESULTS OF MATHEMATICAL MODELING OF NONSTATIONARY WAVES OF STRESSES IN THE COMPLEX-FORM OBJECTS
Abstract
The article deals with evaluation of reliability and accuracy of results of solution of dif- ferent tasks under nonstationary dynamic wave impacts made using the finite element method in displacements. Comparison is made with the results of the analytical decision and dynamic photo of elasticity. The investigated problem is represented in the form of buildings with a base at the influence of nonstationary stress wave
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):71-76
71-76
APPLICATION OF RUNGE-KUTT METHOD AND RUNNING TRI-DIAGONAL MATRIX FOR OPEN HELICOIDAL SHELL CALCULATION
Abstract
The example of the application of the method of Runge-Kutt and running tri-diagonal matrix for thin elastic open helicoidal shells calculations is presented. Comparison of results obtained by half-analytical and analytical methods is given.
Structural Mechanics of Engineering Constructions and Buildings. 2014;(3):77-80
77-80