scholarly journals Multi-cycle crack resistance of the beam with internal crack in operating conditions

2021 ◽  
Vol 18 (2) ◽  
pp. 68-74
Author(s):  
V. I. Smirnov ◽  
◽  
S. S. Maier ◽  
Keyword(s):  
Crack Resistance ◽  
Temperature Dependence ◽  
Cross Section ◽  
Transverse Crack ◽  
Operating Conditions ◽  
Internal Crack ◽  
Repeated Loading ◽  
Arbitrary System ◽  
Concentrated Force ◽  
Operational Factors

The paper examines the effect of some operational factors on the cyclical crack resistance of the beam with an inner transverse crack of the circular shape. The beam with the cross-section of an uneven I-beam joist is positioned on a solid elastic foundation and is subjected to repeated loading by concentrated force. The temperature dependence of the number of loading cycles required for the defect to grow to a given size is established. In addition, on the basis of the principle of the independence of the forces, the residual resource of the beam is assessed in the case of an arbitrary system of forces. The proposed calculation scheme is used to assess the durability of rails.

scholarly journals Fatigue fractureof the beam with an internal transverse crack under multicycle loading

2020 ◽  
Vol 17 (2) ◽  
pp. 75-81
Author(s):  
V. I. Smirnov ◽  
◽  
S. A. Vidyushenkov ◽  
S. S. Maier ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Kinetic Equation ◽  
Critical Load ◽  
Crack Growth ◽  
Elastic Foundation ◽  
Cross Section ◽  
Transverse Crack ◽  
Concentrated Force ◽  
Inspection Interval ◽  
Number Of Cycles

The article considers the beam on a solid elastic foundation with an internal transverse crack of circular shape. The cross-section of the beam has the form of an uneven I-beam joist. The beam is exposed to multiple effects of concentrated force. The proposed calculation scheme is aimed at determining the cyclical strength of the railway rails and specifying the inspection interval. The kinetic equation of crack growth has been obtained and the allowable number of cycles has been specified. The critical load with a single static impact is also assessed. The results are compared with the available experimental data.

scholarly journals Temperature-dependence of the UV cross section of dichlorine peroxide in the tail region of the 244 nm signal

2021 ◽  
Vol 764 ◽  
pp. 138261
Author(s):  
Olfa Ferchichi ◽  
Najoua Derbel ◽  
Thibaud Cours ◽  
Alexander Alijah
Keyword(s):  
Temperature Dependence ◽  
Cross Section ◽  
Tail Region

Analysis of Threshold-Induced Bias Inherent in Acoustic Scattering Cross-Section Estimates of Individual Fish

1975 ◽  
Vol 32 (12) ◽  
pp. 2547-2551 ◽  
Author(s):  
R. T. Weimer ◽  
J. E. Ehrenberg
Keyword(s):  
Cross Section ◽  
Stock Assessment ◽  
Acoustic Scattering ◽  
Operating Conditions ◽  
Scattering Cross Section ◽  
Fish Stock ◽  
Small Fish ◽  
Scattering Cross ◽  
Electronic Circuitry ◽  
Fish Stock Assessment

During acoustic fish stock assessment surveys, it is often desirable to measure the distribution of the acoustic scattering cross-section of single fish. One of the problems in such measurements is that a threshold in the electronic circuitry discriminates against small fish. This effect is analyzed in detail, and an expression is derived for the threshold-induced bias in the mean scattering cross-section estimate. Results are plotted for a typical set of operating conditions.

Effect of an Internal Open Crack on Pipes Wave Propagation

2011 ◽  
Vol 488-489 ◽  
pp. 375-378
Author(s):  
Alessandro Marzani ◽  
Marco Miniaci ◽  
Erasmo Viola
Keyword(s):  
Cross Section ◽  
Guided Waves ◽  
Dispersion Curves ◽  
Internal Crack ◽  
Open Crack ◽  
Axially Symmetric ◽  
Pipe Length ◽  
Pipeline Inspection ◽  
Non Invasive ◽  
The Waves

Stress guided waves in the sonic and ultrasonic regime are acknowledged as a powerful too lto inspect pipes in a non-invasive manner.A key point of the inspection procedure is related to the dispersive behavior of guided waves, that for agiven pipe is defined by the so-called dispersion curves. Such behavior, is generally predicted bymeans ofanalytical formulations. However, when the geometry of the pipe cross-section is not axially symmetric,such as in the presence of an open internal crack running along the pipe length, analytical formulations fail. Here, the computation of the guided waves properties for such a scenario is addressed via a SemiAnalytical Finite Element (SAFE) formulation in which the open crack is modeled at the mesh level.Different crack depths are considered and their effect on the waves dispersion curves are highlighted.The results could be of interest in pipeline inspection and monitoring.

Temperature Dependence of Helium Metastability Exchange Cross Section

1964 ◽  
Vol 135 (2A) ◽  
pp. A353-A357 ◽  
Author(s):  
F. D. Colegrove ◽  
L. D. Schearer ◽  
G. K. Walters
Keyword(s):  
Temperature Dependence ◽  
Cross Section ◽  
Exchange Cross Section

Heat Transfer Characteristics of Various Gun Barrels Under Different Operating Conditions

2019 ◽  
Author(s):  
Mohamed Gadalla ◽  
Muhammad Jasim ◽  
Omar Ahmad
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Cross Section ◽  
Wall Temperature ◽  
Circular Cross Section ◽  
Typical Case ◽  
Operating Conditions ◽  
Firing Process ◽  
Transfer Model ◽  
Gun Barrel

Abstract The thermal stability parameter is an important parameter for predicting the lifespan of structures. In this paper, a two-dimensional transient heat transfer model of machine gun barrels undergoing continuous firing developed and analyzed for different geometries and thermal properties. The model for the transient thermal analysis is based on the forced convection heat transfer at the inner surface of the gun barrel. Finite element simulations were performed to predict the interior and exterior barrel temperature profiles and temperature contours after continuous firing process. The incomplete Cholesky Conjugate Gradient (ICCG) solver was adopted in solving unsymmetrical thermal transient analyses. The material thermal behavior studied for the basic circular cross section of gun barrels showed that the lowest inner wall temperature was for high rounds was achieved in steel barrels due to the rapid conducted and convective heat transfer to the environment. While the highest inner wall temperature was recorded for ceramic STK4 barrels and an increase of inner wall temperature by 17% was observed as compared to the typical case of circular cross section steel barrel. In general, a higher inner temperature in the gun barrel is undesirable and harm due to the possibility of reaching the cook-off scenario at earlier rounds. Results concluded that non-circular geometries with constrained cross section areas of typical case improve thermal management and the hexagonal geometry had the best thermal management and could provide more rounds for users. In addition, titanium barrels would have a weight drop of 41% while the overall barrel’s temperature increases by 49%.

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