scholarly journals Modeling of corrosion-mechanical behavior of multi-element metal structures of transport works in real-world conditions

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Valentin Chernykh
Keyword(s):  
Corrosion Damage ◽  
Corrosive Wear ◽  
Joint Effect ◽  
Euler Method ◽  
Arbitrary Cross Section ◽  
Corrosion Wear ◽  
Corrosive Media ◽  
Intermediate Point ◽  
Railway Bridges ◽  
Metal Structures

The article is part of the author’s dissertation research. Multi-element metal structures are widely used in the construction of transport structures (metal spans, trusses of railway bridges, overpasses, etc.). During operation, such structures are subjected to the joint effect of loads, temperatures, and corrosive media. In accordance with this, the task of predicting the behavior of such structures seems to be relevant. It consists in the development of effective models oriented to the calculation of the bearing capacity of structural elements subjected to corrosive wear. The article discusses the most common corrosion damage to metal multi-element structures of transport facilities, the classification of corrosion processes according to the nature of the surface destruction, the main types of metal elements and bridge structures. The main parameters characterizing the corrosive wear of metal structures were determined. Ways to account for the effect of aggressive environment on metal structures, i.e. well-known mathematical models and work, in which attention is paid to the problem of corrosion, wear modeling. The process of identifying corrosion wear models (determining unknown model coefficients) is described. The system of equations for determining the coefficients of a mathematical model of corrosive wear is given. The values of the coefficients of the models used to predict the behavior of structures, with a different choice of an intermediate point are given. A statically indefinable flat five-element truss of arbitrary cross section, part of the rods of which works in tension and part in compression is considered. For this design solves the problem of assessing durability. To solve this problem, use the corrected Euler method. The obtained numerical values of the durability of trusses of five rods, depending on the lengths of the rods.

On corrosion damage and its connection with non-metal inclusions in elements of pipe metal structures of NPP

2020 ◽  
pp. 148-156
Author(s):  
A. S. Mitrofanov ◽  
Ye. A. Krainyuk ◽  
S. V. Gozhenko ◽  
V. N. Voyevodin ◽  
R. L. Vasilenko
Keyword(s):  
Corrosion Damage ◽  
Metal Structures ◽  
Pipe Metal

Discussion on Venkat & Spaulding: “Numerical Simulation of Nonlinear Free-Surface Flows Generated by a Heaving Body of Arbitrary Cross Section”

1991 ◽  
Vol 35 (03) ◽  
pp. 250-253
Author(s):  
Apostolos Papanikolaou
Keyword(s):  
Free Surface ◽  
Cross Section ◽  
Euler Method ◽  
Free Surface Flows ◽  
Arbitrary Cross Section ◽  
Circular Cylinders ◽  
Published Data ◽  
The Time Domain ◽  
Heave Motion ◽  
Nonlinear Free Surface

A method has been presented recently by Venkat and Spaulding to solve the nonlinear boundary-value problem of oscillating two-dimensional cylinders of arbitrary cross section on the free surface of a fluid. The method relies on a second-order finite-difference technique with a modified Euler method for the time domain and a successive over-relaxation procedure for the spatial domain. The authors compare their numerical results with those of other authors (theoretical and experimental), as they have published data for specialized forms like a wedge, circular cylinders, and ship-like sections in forced heave motion (references [4] to [7] and [22], [23] of the paper).

Destruction Patterns of X70 Steel Sample, Possessing Cracks of Corrosion-Mechanical Origin, under Cyclic Loading

2019 ◽  
Vol 946 ◽  
pp. 20-24 ◽  
Author(s):  
O.A. Nasibullina ◽  
A.G. Gareev
Keyword(s):  
Steel Sample ◽  
Fatigue Tests ◽  
Relaxation Processes ◽  
Corrosive Media ◽  
Mechanical Destruction ◽  
Metal Structures ◽  
Gradual Accumulation ◽  
Accumulation Of Damage ◽  
Machine Parts ◽  
Focal Zone

Most of the structures, parts of machines in the process of operation are subjected to the action of cyclically changing loads, such changes can be judged by the fatigue of the metal. In addition to the influence of mechanical stresses during the service, corrosive environment affects metal structures, machine parts, which leads to the process of gradual accumulation of damage. Corrosive media leads to a decrease in durability. The paper presents results of fatigue tests on a sample of steel X70, selected from the focal zone of destruction of the main gas pipeline. The sample under investigation had numerous cracks typical for corrosion-mechanical destruction. It is shown that with an increase in the number of loading cycles, the electrode potential of the metal decreases, which leads to a decrease in its thermodynamic stability. With the growth of the crack, there is a decrease in the potential, which is not compensated by the relaxation processes. Results of the regression analysis showed that the correlation coefficient is r = 0.99, using the three-parameter logarithmic function.

scholarly journals Design of circular flexible plates under of corrosion wear

2021 ◽  
Vol 263 ◽  
pp. 03007
Author(s):  
Vladimir Mavzovin ◽  
Igor Ovchinnikov
Keyword(s):  
Fatigue Life ◽  
Optimal Design ◽  
Service Life ◽  
Quadratic Programming ◽  
Sequential Quadratic Programming ◽  
Minimax Problem ◽  
Corrosive Wear ◽  
Optimal Thickness ◽  
Programming Technique ◽  
Metal Structures

The problems of optimal design of metal structures are usually formulated as the problem of finding such values of the selected parameters of structures that provide the smallest (or largest) value of the selected optimality criterion in the area of admissible design solutions. In most works on the optimization of metal structures, parametric problems are considered, limited by the preliminary assignment of a constructive form with the possibility of changing its parameters. To solve these problems, both deterministic and probabilistic optimization models can be used. A deterministic problem of optimal design of flexible round metal plates exposed to the combined action of a load and an aggressive environment causing corrosive wear of one of the plate surfaces is considered. A feature of the statement is that it takes into account the effect of the stressed state of the plates on the kinetics of their corrosive wear. Due to the insufficient efficiency of random search methods, the sequential quadratic programming technique is used. Two formulations of the optimal design problem are formulated, which are reduced to the minimax problem. 8 optimization projects were considered, their comparative analysis was carried out. It is shown that the realization of the found optimal thickness profiles leads either to a significant decrease in the stress level at the end of the plate’s service life, or to a significant increase in the service life. Calculation results show that maximum fatigue life designs are equal at end-of-life, and the maximum increase in fatigue life for hard- pinned inserts along the contour is 59%. As a result of the study, it was found that the problems of optimal design of flexible round plates under conditions of corrosive wear (the rate of which depends on the level of stresses in the plates), presented in the form of a minimax problem, can be effectively solved using the sequential quadratic programming technique, and the study of time evolution is intense -strain state can be carried out using a combination of the mesh method and the Adams method. Realization of the found optimal thickness profiles leads either to a significant decrease in the stress level at the end of the plate’s service life, or to a significant increase in the service life.

scholarly journals REDUCING THE FORCE RESISTANCE OF STEEL COLUMNS IN INDUSTRIAL BUILDINGS WITH CORROSION DAMAGE DURING OPERATION

2020 ◽  
Vol 8 (4) ◽  
pp. 9-13
Author(s):  
Nina Buzalo ◽  
Ivan Gontarenko ◽  
Boris Chernykhovsky
Keyword(s):  
Experimental Study ◽  
Corrosion Damage ◽  
Building Structure ◽  
Safe Operation ◽  
Metal Structures ◽  
Steel Columns ◽  
Industrial Buildings ◽  
Calculation Results

When conducting inspections of metal structures of industrial buildings, one of the most characteristic damages is revealed - corrosion. To assess the degree of serviceability and the possibility of further safe operation of a building structure or a building and structure, it is necessary to correctly assess the danger of corrosion damage and determine the possibility of further operation. To assess the strength resistance of damaged structures, it is necessary to correctly assess the danger of corrosion damage and determine the possibility of further operation. For this purpose, an experimental study of columns with simulated corrosion damage was carried out and compared with the calculation results according to regulatory recommendations.

Numerical Simulation of Nonlinear Free-Surface Flows Generated by a Heaving Body of Arbitrary Cross Section

1990 ◽  
Vol 34 (02) ◽  
pp. 92-104
Author(s):  
N. Kolluru Venkat ◽  
M. L. Spaulding
Keyword(s):  
Free Surface ◽  
Potential Flow ◽  
Euler Method ◽  
Flow Equation ◽  
Free Surface Flows ◽  
Arbitrary Cross Section ◽  
Domain Model ◽  
Dimensionless Frequency ◽  
Surface Boundary ◽  
Nonlinear Free Surface

A two-dimensional potential-flow model is employed to predict the wave and flow fields generated by wedge, circular, and semicircular cylinders and ship-shaped bodies in forced heaving motion. The case of a wedge penetrating still fluid at constant velocity is also studied. The model solves the potential flow equation, including the full nonlinear free-surface boundary conditions on a boundary-fitted coordinate system. The model equations are solved using a second-order finite-difference technique with a modified Euler method for the time domain and a successive over relaxation procedure for the spatial domain. Model predictions for the force coefficients and phase angles and the associated hydrodynamic mass and damping coefficients of the heaving bodies are generally in good agreement with available analytic theories and data for the dimensionless frequency range, 0

Texture Changes of Carbon Steel and Stainless Steel as a Result of Wear

2005 ◽  
Vol 495-497 ◽  
pp. 441-446
Author(s):  
M. Reza Bateni ◽  
Jerzy A. Szpunar ◽  
X. Wang ◽  
Dong Yang Li
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Wear Test ◽  
Corrosive Wear ◽  
Fiber Texture ◽  
Corrosion Wear ◽  
Wear And Corrosion ◽  
Aisi 1045 ◽  
Steel Aisi ◽  
Wear Tests

In this research, surface texture changes of carbon steel AISI 1045 and stainless steel AISI 304 under simultaneous wear and corrosion were investigated. A solution of 3.5 % wt. NaCl was used as the corrosion agent and a pin-on-disk tribometer was employed to perform wear and corrosion wear tests.Texture investigations of the worn samples have shown texture changes after wear and corrosion-wear tests. In worn carbon steel samples after dry wear test, {011}<100> and {111} fiber texture components were developed in initially random oriented samples, whereas under corrosive-wear conditions, {111}<011> texture and {001}<110> texture were developed. In the stainless steel samples, {112}<110> texture component was observed under both dry and corrosive wear conditions, in the samples that had random grain orientations before corrosion and corrosion-wear tests.

Corrosive media of Orenburg gas condensate field on the condition of metal structures

1996 ◽  
Vol 32 (6) ◽  
pp. 610-614 ◽  
Author(s):  
N. A. Gafarov ◽  
A. A. Gocharov ◽  
A. S. Grintsov ◽  
V. M. Kushnarenko
Keyword(s):  
Gas Condensate ◽  
Corrosive Media ◽  
Metal Structures

scholarly journals INFLUENCE OF CORROSION DAMAGE ON INNER LAYERS OF FLEXIBLE HYDRAULIC CONNECTION DURING OPERATION

2018 ◽  
pp. 17-22
Author(s):  
Valeriy Ivanovich Kolodyazhnyy ◽  
Valentina Makarovna Oreshkina ◽  
Lyudmila Sanduovna Baeva ◽  
Zhanna Victorovna Kumova ◽  
Artem Leonidovich Petrov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Corrosion Damage ◽  
Structural Defects ◽  
Near Surface ◽  
Hydraulic Connection ◽  
Temperature Changes ◽  
Metal Structures ◽  
Rubber Layer ◽  
Brittle Damage ◽  
Significant Temperature

Operation of mechanisms and equipment under significant temperature changes can cause brittle destruction not only of metal structures. In the process of research of high pressure hose of camber mechanism there was revealed violation of the tightness of the outer rubber layer, which led to further penetration of acid-alkaline environment (moist sea air) into the formed voids in winding layers. In the damaged segments the torn filament ends of metal coiling of flexible hydraulic connection seem typical of brittle damage. Further study of macro-and microstructure of the material of metal filaments of the wire and detailed analysis of the near-surface layer revealed violation of the technology of protective coating of the filaments. The low quality of brass coating of the metal coiling of DN20 wire of the hydraulic connection resulted in the rapid corrosion attack. The presence of structural defects in the near-surface layer led to the formation of discontinuities of brass coating, to a decrease of adhesion characteristics of the metal coiling. Iron oxide being a product of corrosion of metal filament coiling in the formed voids between the layers slashed under bending effected by friction contact and alternating loads. The research results can be used for developing effective anti-corrosion methods for flexible hydraulic connections.

INVESTIGATION OF CORROSION WEAR OF SUPPORTING METAL STRUCTURES OF FREIGHT CARS DURING MEASURES TO EXTEND THE TERM OF SERVICE

2020 ◽  
pp. 43-53
Author(s):  
D. Bulich ◽  
S. Sapronova ◽  
V. Tkachenko ◽  
A. Koshel
Keyword(s):  
Statistical Analysis ◽  
Residual Life ◽  
Corrosion Wear ◽  
Load Bearing ◽  
Metal Structures ◽  
Individual Approach ◽  
Freight Car

All elements of load-bearing metal structures of freight cars are subject to corrosion wear. In this article, a statistical analysis of corrosion wear for each element of load-bearing metal structures. Damage to load-bearing metal structures of gondola cars taking into account corrosion wear is considered. Measures to increase the possible maximum corrosion wear, which can be used to predict the residual life and structural finishing of the elements of load-bearing metal structures. Cracks and fractures that are not detected in time, which turn into through-corrosion during operation, have a great impact on corrosion. To determine the corrosion of the freight car requires an individual approach to each element of the load-bearing structures of the car, taking into account the performance and time of repair.Studies have shown that half of freight cars were operated with corrosion of some elements of load-bearing metal structures more than 30%. This shows the possibility of increasing the tolerance of the threshold of corrosion wear of cars, which will affect the ability to reduce the exclusion of freight cars from the inventory.

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