Bar structures are widespread in construction due to their economy, freedom of design shapes and sizes. As a result, automation of design and calculation of such structures is an urgent task. As part of the study, the task of developing a software module that generates a map of optimal cutting of rolled metal based on the results of calculations of rod structures has been implemented. The algorithm under consideration takes into account such features of the cutting optimization problem as taking into account the width of the blade, the possibility of using half the size of the rolled product, support for optimization of several sections, and welding of parts in case the length of the workpiece is exceeded. The software module is developed using JavaScript and C# languages. The ability to automatically generate cutting maps based on the results of optimization of rod structures increases the efficiency of designing building structures.

Keywords: Design in construction, bar structure, computing system, web development, design in construction, rod structure, computer system, web development, optimal cutting, rolled metal, cutting map

The simulation of a multilayer structure in the finite element Ansys complex is considered. The design consists of 10 layers, each of which has certain specific properties. The model is an imitation of the soil base pavement. We consider the simulation in the form of a simplified, flat statement of the problem. The analysis of the oscillations under impact. The wave field of displacements at a given part of the structure is analyzed. Based on a numerical experiment, an approach to estimating the characteristics of a layer is constructed.

Keywords: multi-layer construction, vibration diagnostics, simulation, FEM, Ansys, pulse action, dynamics, fluctuations

The modeling of a hollow core slab in the finite element complex Ansys is considered. The construction of a 3D model is considered. Numerical modeling was carried out under static loading of the floor slab. The influence of material properties on the parameters of the stress state and deflection of the structure is investigated. Based on a numerical experiment, an approach to assessing the characteristics of a structure is constructed.

Keywords: hollow core slab, static analysis, modeling, FEM, Ansys, stress state, deflection

The task of creating a file format containing an image having an optimized (compressed) size is considered. The source file is in BMP format. The problem is solved on the basis of optimal interpolation of the data by polynomials of various degrees. The simulation of the algorithmization process was performed in the MATLAB package. The proposed algorithm showed good compression of the initial information.

Keywords: image, BMP format, compression, algorithm, polynomial regression

The concept of “partial failure” used in practice is analyzed as a state in which the possibility of continuing the operation of a technical device remains. It is argued that partial failures are widespread in the operation of technology, but unlike full failures, under which the continuation of work becomes impossible in any mode, not fully understood. A number of reliability indicators are proposed that take into account the specifics of partial failures and the possibility of continuing work when they occur. Attention is drawn to the fact that the decision to continue the operation of the device in the presence of a partial failure is associated with risks. The essence of the risks lies in the possibility of receiving damage in the form of further deterioration of the technical condition of the partially failed device. However, in many cases such a risk may be justified. The task of deciding on the continuation of the operation, in the conditions of a partial failure is a complex task of system analysis. Its solution will require the use of complex models compiled using modern methods of mathematical descriptions and research.

Keywords: partial failure, reliability theory, reliability indicators with partial failure, risks of continued operation, making decisions on continuation of operation

The problem of identification of defects in the construction in the form of a wall element is considered. Numerical simulation of the structure is carried out in the Ansys finite element complex. The investigated model of a wall structure has a defect in the form of a through crack, of a certain length. The edges of the cracks do not interact with each other. The excitation of the structure under pulsed loading is considered. Wave field displacements at control points are analyzed. Identified signs of identification of crack-like defect.

Keywords: numerical modeling, wall element, defect, crack, identification, finite element modeling, dynamic analysis, oscillations, displacement wave field

The study on the hardness of samples from steel ST3 and 15G. On the basis of the correlation equations obtained values of ultimate strength of the examined steels. With the application of the law of three-parameter Weibull distribution constructed density distribution and the resulting minimum value of ultimate strength. The obtained results are proposed to use to determine the value of the resource for load-bearing systems of vehicles.

Keywords: reliability, lifetime, the hardness of steel, strength of steels, the endurance limit of steels, the Weibull law

The article presents the quality assessment of repair work for electricity pilons of transmission line performed by the method of vibration diagnostics. The suggested criterion for assessing the quality of the repair is relative adhesion of repair layers to the base of the stand. Modeling of structural oscillations strut mount, transmission lines and calculations in the finite-element complex Ansys. The dependence of the parameters own frequency of fluctuations of the value of damage at different values of the space adhesion. The resulting equations based on changes in natural frequencies on the magnitude of adhesion. The calculation of the relative adhesion of the repair composition to the concrete model of the design. The material presented can be used for assessing the quality of repair work of different structures of the core type reinforced concrete structures.

Keywords: vibration diagnostics, quality, repair of structures, defect, adhesion, natural frequencies

The article presents the algorithm of repair work for electricity pilons of transmission line.The technical diagnostics based on complex method includes a visual inspection, instrumental and vibration diagnostics for electricity pilons of transmission lines. Pilons has defects: inclined cracked faces with a length of 25-30 cm , with a crack width of 0,4-0,7 mm . Were selected effective repair compositions for restoring reinforced concrete structures rack transmission towers:modified fine-grained concrete, polymer concrete. The article presents an example of analytical modeling of natural vibrations of a reinforced concrete pilons of transmission lines with defects in the base. This article contains a list of repair works. The material presented can be used in the development of methods of diagnostics and monitoring of technical condition of different structures of the core type.

Keywords: Algorithm, repair, category of defects, non-destructive testing methods, pilons of transmission lines, vibrodiagnostics

This paper proposes a method for detecting damage truss rod cantilever structure on the basis of new information sign "Express - distinguishing between" damage. It is based on the analysis of the phase diagrams for modeling its transient oscillations. Produced comparison of various parameters damped oscillations truss rod design for the structure without damage and corruption. Processed and analyzed the frequency response based on them phase diagrams. To analyze the response considered in the frequency range from 0 to 100 Hz. An analysis of the phase diagrams in different frequency regions design is presented as an information sign "Express - distinction" of having damage to the truss.

Keywords: Truss rod design, damage, finite element modeling, information sign, transient fluctuations of the amplitude-frequency analysis, phase diagrams

The article presents the vibration diagnostics method for pilons of transmission lines. Pilons has defects: inclined cracked faces with a length of 25-30 cm , with a crack width of 0,4-0,7 mm . The article presents an example of analytical modeling of natural vibrations of a reinforced concrete pilons of transmission lines with defects in the base. Analytical modeling was based on the hypotheses of Euler-Bernoulli. Built an equivalent model of the pilons with defect in the form of an elastic element, simulating the damage in the area of trapping. The calculation of natural frequencies of first five modes of transverse oscillations for different values of stiffness of the defect. The result of this work is to obtain the dependencies of the relative frequencies from the stiffness of the defect and establishment of sufficiently informative criterion for predicting the alarm state of structures. The material presented can be used in the development of methods of diagnostics and monitoring of technical condition of different structures of the core type.

Keywords: vibration analysis, pilons of transmission lines, the defect, analytic modeling, transverse vibrations, natural vibrations, natural frequencies

the paper considers the comparison of natural modes for the first and second transverse oscillation modes obtained by numerical simulation and finite element package of analytical calculation of the core model with an elastic element based on the application of the Euler-Bernoulli hypothesis. The analysis compared waveforms for different values of the defect shows their satisfactory agreement.

Keywords: rod design, vibrations, defect, finite element modeling, analytical modeling, waveform

The mixed finite element method has advantages over classical formulations of Lagrange and Castigliano, and ensures high precision and smoothness approximate solutions for strains and stresses.
In practice, using the mixed finite element method is limited by high size of linear equation systems, which leads to significant increasing time costs.
Using the orthogonal finite functions for approximating of unknowns leads to generation of sparse linear systems with a special structure.
That system can be simplified during solution.
This article proposes the algorithm of modificated Gaussian elimination for preliminary transformation an extended matrix of linear system.
This algorithm underlies software complex, which includes LISTSOLVER, the author's solver.
Confirmed the efficiency of created solver in compare with common-type solver.

Keywords: mixed finite element method, sparse linear systems, orthogonal finite functions, Gaussian elimination

The main maintenance of a  results of calculation of a thermointense condition of beams depending on various ways of an attachment to the basis - jammed in the basis, with absolutely hard sealing-off on end faces and absence of any communications at end faces is considered. The analysis shows, that the more age of "blocks-communications", the more they possess rigidity. It means, that they are less pliable, and sizes of pressure in the settlement block are close to pressure in the block with the jammed end faces.  

Keywords: Termointense, concrete, block, communication, support, suppleness, pinched, temperature, movement

Defined criteria for identification of defect parameters, on the basis of the analysis of the different modes of own fluctuations, with the use of finite element modal calculation console corpulent model of a rod with a single defect. Developed finite element model of a universal complex . Considered corpulent (3-d) model on the basis of 3D finite element Solid92. When solving the problem considered on 26 oscillation modes depending on the size of the defect and its location.

Keywords: Damaged, defective, swing, cantilever, frequency