scholarly journals EXPERIENCE OF INSPECTION OF DAMAGES OF METAL BEARING STRUCTURES

2021 ◽  
Vol 9 (4) ◽  
pp. 16-20
Author(s):  
Sergej Evtushenko ◽  
Marina Shutova ◽  
Boris Chernykhovsky
Keyword(s):  
Technical Condition ◽  
Elastic Region ◽  
Place Of Death ◽  
Industrial Building ◽  
Structural Elements ◽  
Ansys Software ◽  
Good Convergence ◽  
Truss Element ◽  
Metal Element ◽  
Before And After

The article deals with the damaged metal structural elements of the out-center compressed I-pillar, corner of a single corner and others. The work of the metal element in the elastic region was experimentally studied and compared with the results of FEM calculation using ANSYS software. Good convergence of results (less than 5%) is received at calculation of stresses in a place of death of the damaged basic brace of a truss of an industrial building. The reliability of the truss element with a defect (0.892) and without it (1.0) and the category of technical condition before and after damage are determined. Despite the fact that the voltage at the site of the defect does not exceed the maximum permissible, the category of technical condition changes from serviceable to serviceable category, and the design itself must be repaired with the elimination of damage on the support strip.

scholarly journals The projected effect from acceptance of constructive solutions to ensure the reliability of an industrial facility

Vestnik MGSU ◽  
2015 ◽  
pp. 68-79
Author(s):  
Tat’yana Vladimirovna Zolina ◽  
Pavel Nikolaevich Sadchikov
Keyword(s):  
Solid Wall ◽  
Extended Period ◽  
Industrial Building ◽  
Transverse Displacement ◽  
Structural Elements ◽  
Industrial Facility ◽  
Tower Crane ◽  
Before And After ◽  
Effective Option ◽  
Low Altitude

The article raises the problem of increasing the reliability of an industrial building bearing the entire set of frame disturbances. One of the ways to solve it is to mount extra structural elements, previously unrecorded in the design of the object. During the study we examined some of them: installation of mechanical transverse stiffening diaphragms; increasing the rigidity of the column part above the crane; arranging connecting rods located in levels of covering in the temperature seam and crane beams. Choosing the most effective option is determined by constructive and technological features of the research object. In our case, it acts as a one-storey industrial building of hull workshop of Astrakhan maritime shipyard, equipped with overhead cranes. Using this example the calculations, which were carried out, allow estimating the effect from acceptance of constructive solutions for installation of reinforced concrete diaphragms of stiffness at the edges of framework and increase the rigidity of the column part above the crane. During the study four options are considered for calculation scheme using wall panels. These should include representation of the device: as a solid wall; in two columns wide; for large aperture sizes; at the low altitude of the end of the opening. We have presented a comparative analysis of the results before and after the introduction of the corresponding elements in the calculating model of the research object. In the accepted system of constructive measures disc coating with high horizontal rigidity distributes the load on the front diaphragm. Increasing the stiffness of above the tower crane column part gives an additional effect, as an overhead crane is located closer to the cover and in case of the column of more developed section in the above the crane area, it passes the covering greater effort. In its turn, it prevents the transverse displacement and rotation, involving the entire framework into operation. The introduction of these measures contributes to: equal declining of displacements of stresses loads from the action of the nodal points of the frame, both in the level of brake beams and in the surface level; increasing the period of achieving the object’s maximal allowable condition and an extended period of its faultless operation.

Probabilistic Analysis of Intermediate Floor Steel and Wooden Structures in the Old Urban Development Building

2014 ◽  
Vol 633-634 ◽  
pp. 1140-1147
Author(s):  
Vladimir Alekseevich Sokolov
Keyword(s):  
Information Theory ◽  
Urban Development ◽  
Probabilistic Analysis ◽  
Technical Condition ◽  
Probabilistic Methods ◽  
Technical Diagnostics ◽  
Structural Elements ◽  
Complex Technical Systems ◽  
Technical Systems ◽  
Wooden Structures

The article suggests an approach to determine structural elements technical condition, based on the mathematical probabilistic apparatus of technical diagnostics. Diagnostics are performed using probabilistic methods of complex technical systems conditions recognition. Probabilistic parameters are calculated according to Bayes’s rule. The paper shows a diagnostics example of intermediate floor elements and systems in the old urban development building. Both the suggested method and information theory methods are used during diagnostics.

Conception and Practical Application of a Measuring Device for Energetic Parameters Measurement of a Mechatronic Object

2011 ◽  
Vol 180 ◽  
pp. 185-193 ◽  
Author(s):  
Aleksy Cwalina ◽  
Marcin Zacharewicz
Keyword(s):  
Synchronous Generator ◽  
Technical Condition ◽  
Measured Quantity ◽  
Structural Elements ◽  
Measuring Device ◽  
Non Invasive ◽  
Invasive Method ◽  
Method Of Evaluation ◽  
Parameters Measurement ◽  
Gas Pressures

In the article assumptions of the developed non-invasive method of evaluation technical condition of selected structural elements of the ship's diesel-electric set at limited monitoring susceptibility, when the engine is not equipped with indicator valves, are discussed. The method is based on simultaneous measurements of phase-to-phase voltage of the synchronous generator, exhaust gas pressures in the exhaust manifold, and vibration accelerations of some parts of the set. To the purpose of the accomplishment all measurements of energetic parameters at the same time, it turned out to be necessary to design and construct the measured quantity converter. In the paper requirements in relation to such a converter, technical project, and representative results of measurements conducted on a real object – diesel-electric set type ZE400/52 – are presented.

EXPERIMENTAL INVESTIGATION OF THE DURABILITY OF LOAD BEARING TIMBER-GLASS COMPOSITES UNDER THE EFFECTS OF ACCELERATED AGING

2019 ◽  
Vol 14 (2) ◽  
pp. 45-59 ◽  
Author(s):  
Halet Almila Arda Buyuktaskin ◽  
Mehmet Serkan Yatagan ◽  
Gulseren Erol Soyoz ◽  
Leyla Tanacan ◽  
Morvarid Dilmaghani
Keyword(s):  
Raw Materials ◽  
Accelerated Aging ◽  
Structural Elements ◽  
Atmospheric Conditions ◽  
Aging Effects ◽  
Glass Composite ◽  
Load Bearing ◽  
Glass Composites ◽  
Before And After

Although timber was used extensively as a structural material for traditional buildings in Turkey in the past, usage of structural timber decreased significantly over time and timber has been largely replaced by other materials. As timber is a natural, durable and sustainable material, it would be desirable to re-introduce timber structural elements to contemporary construction in a form that is appealing to industry. Timber-glass composite structural elements are potentially a good candidate for this purpose. To that end, a series of tests were conducted on load-bearing timber-glass composites in order to understand the long–term structural performance of the composite material under atmospheric conditions; to decrease the recurring cost of repair and maintenance; and to minimize the exhaustion of raw materials and energy. In this paper, the first part of this experimental work is presented, which focuses on the durability of timber-glass composite under the effects of accelerated aging, carried out on small-sized timber-glass composite specimens. Accelerated aging effects were observed under wetting-drying, freezing-thawing, UV effects, resistance to acids and high temperature. The mechanical strength of the timber-glass composite specimens before and after the effect of accelerated aging was measured by adhesion and shear strength tests and a comparative analysis of the results was carried out. The results of the experiments indicate that timber-glass composite is suitable to be used under protection from environmental conditions.

scholarly journals Influence of the Acoustic Cover of the Modular Expansion Joint on the Acoustic Climate in the Bridge Structure Surroundings

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2842
Author(s):  
Janusz Bohatkiewicz ◽  
Michał Jukowski ◽  
Maciej Hałucha ◽  
Marcin Dębiński
Keyword(s):  
Sound Level ◽  
Structural Elements ◽  
Expansion Joint ◽  
Expansion Joints ◽  
The Road ◽  
Sound Levels ◽  
Road Surfaces ◽  
Before And After ◽  
Bridge Structures

The noise generated at the interface between the wheels of vehicles and the road surface is well recognized in the literature worldwide. Many publications describe the phenomenon of reducing this kind of impact by silent road surfaces. A specific type of this noise is the sound generated by vehicles passing over the expansion joints of bridge structures. Due to the impulsive nature of this sound, it is very onerous for people living in the close vicinity of bridge structures. The passage of vehicles over expansion joints causes the formation of vibrations that are transmitted to the structural elements of bridge structures, which may cause the formation of the material sounds (especially arduous in the case of bridges with steel elements). An attempt to reduce this impact was made by making a prototype acoustic cover of the expansion joint on the selected bridge. The paper presents the results of research on the “in situ” acoustic effectiveness of this cover. Additionally, the noise was modelled in the object surroundings before and after the cover’s application. The acoustic efficiency of the cover in the whole measured frequency range was 5.3 dBA. In the narrower frequency bands (1/3 octave bands), larger sound level reductions were observed. The maximum sound levels measured under the tested dilatation were less than 10.0 dBA lower than the maximum sound levels measured under the reference dilatation.

scholarly journals Analysis of repair works to remove the effects of structural failure after a gas explosion

2019 ◽  
Vol 284 ◽  
pp. 02002
Author(s):  
Aleksandra Bąk ◽  
Ryszard Chmielewski
Keyword(s):  
Residential Buildings ◽  
Residential Building ◽  
Technical Condition ◽  
Structural Elements ◽  
Structural Failure ◽  
Gas Explosion ◽  
Gas Explosions ◽  
Construction Supervision ◽  
Bearing Structure ◽  
Construction Works

The article presents the issues of repair works in a multi-family residential building, whose structural and non – structural elements have been damaged and destroyed by a gas explosion and the fire. Gas explosions in residential buildings constitute a small percentage of the total number of building disasters, however, due to the relatively large number of injured people, these incidents are very dangerous [1]. Moreover, the gas explosion often leads to significant material losses and fatalities. Proper assessment of the load-bearing structure after such incident requires an extensive knowledge of the behaviour of structures. The first authority, that issues a decision regarding further use is Construction Supervision Inspector. Until the demolition of the object is ordered, the next step is to provide expert report made by an authorized construction expert, whose aim is to assess the technical condition of the elements of the structure and to determine the scope of necessary repair works. Construction expert, who give such opinion during the assessment of objects immediately after such incident, often has limited access to structural elements, moreover these elements often are covered. Hence, the recommendations contained in these reports often do not include all of required construction works.

scholarly journals Development of strategy for ensuring operability of transport and technological machines

2020 ◽  
Vol 164 ◽  
pp. 03046
Author(s):  
Sergey Repin ◽  
Sergey Maximov ◽  
Andrei Zazykin ◽  
Nikolay Voropaev
Keyword(s):  
Technological Process ◽  
Technical Condition ◽  
Structural Elements ◽  
Transport Equipment

The article presents the results of research in the field of ensuring the performance of complex technical objects on the example of transport and technological machines (TTM), which include transport equipment, as well as technological machines (excavators, loaders and other equipment that performs a technological process). The strategy of forming a system of maintenance and repairs taking into account the technical condition of TTM elements is described. The strategy provides for the division of structural elements of machines into four groups, depending on the principle approach to calculating the frequency of their repair. The criterion for determining the frequency of repairs is the probability of reaching the maximum values of characteristics during the inter-repair period, as well as the degree of criticality of the consequences of possible failure of the element.

scholarly journals Structural health monitoring and structural modifications of industrial building subjected to dynamic loading

2020 ◽  
Vol 313 ◽  
pp. 00021
Author(s):  
Robert Soltys ◽  
Michal Tomko ◽  
Ivo Demjan
Keyword(s):  
Load Transfer ◽  
Steel Structure ◽  
Industrial Building ◽  
Construction Work ◽  
Structural Behaviour ◽  
Structural Modifications ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Before And After ◽  
Complex Structural

A complex structural, static and dynamic review of an existing steel ceiling has been realised after two years of service and the completion of subsequent construction work. The construction work involved the reconstruction of a steel structure and structural modifications to the ceiling, which is part of the production hall. The construction work was realised in order to reduce the vibration response of the ceiling. The interior of the steel structure was supplemented by steel structural elements to share the load transfer of automatic washing machines. The structural behaviour of the ceiling was monitored before and after the modification. Accelerations of the ceiling were time-domain-monitored at specific locations. Measured data was transformed to the spectral-domain which is represented by power spectral densities.

scholarly journals Assessment of technical condition and repair of steel structure elements on the example of fire damage in a warehouse building

2019 ◽  
Vol 284 ◽  
pp. 02001
Author(s):  
Andrzej Ambroziak ◽  
Paweł Piotrkowski ◽  
Tomasz Heizig
Keyword(s):  
Steel Structure ◽  
External Source ◽  
Technical Condition ◽  
Actual Condition ◽  
Test Results ◽  
Structural Elements ◽  
Site Investigations ◽  
Laboratory Test Results ◽  
Repair Procedure

The paper analyses a case study on the structural assessment of warehouse building partially damaged by fire caused by external source (fire of lorries close to the building). The authors focus on the site investigations and laboratory test results prior to assessing actual condition of the structural elements. Both strengthening concept and repair procedure of a steel column are addressed here. A short literature survey in the paper regards fire damages and its impact on the entire structural systems and its members.

scholarly journals APPLICATION OF BREAKDOWN MECHANICS FOR PREDICTING THE RESOURCE OF AXIAL RADIAL HYDROTURBINS

2019 ◽  
Vol 20 (9-10) ◽  
pp. 71-78
Author(s):  
E. V. Georgievskaia
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Critical Length ◽  
Technical Condition ◽  
Ansys Software ◽  
Limiting State ◽  
Hydraulic Unit ◽  
Actual Operation ◽  
Hydraulic Turbines

To plan for timely reconstruction, modernization, repairs or replacement of equipment it is important to reliably predict the instant of its transition to the limiting state that determines the lifetime. Currently, there are no regulatory methods for assessing the lifetime of hydraulic turbines at the operation stage. The approach presented in this paper uses the fracture mechanics methods to build a long-term individual forecast of the dangerous development defects in the main elements of hydraulic turbines taking into account design, technological and operational features. The forecast is based on three-dimensional mathematical models that describe the change in the technical condition of the equipment during time under actual operation. The ANSYS software is used for calculations. Models take into account the size and position of detected or possible defects. Crack growth is determined by the combination of low- and high-frequency loads. The critical length of the crack corresponds to the instant of change of the crack development mechanism, when the failure risk increases sharply. Proposed approach can significantly reduce the possibility of unplanned or emergency shutdown of the hydraulic unit due to its destruction during the overhaul period.

Sign in / Sign up

Export Citation Format

Share Document