scholarly journals IDENTIFICATION AND VERIFICATION OF MATERIAL FUNCTIONS OF THE CREEP MODEL UNDER THERMAL RADIATION EFFECTS FOR AUSTENITIC STEEL 1X18H10T

2020 ◽  
Vol 82 (1) ◽  
pp. 89-99
Author(s):  
V.A. Gorokhov

In the present paper, on the basis of the information available in the scientific literature on the thermal creep rate of 1X18H10T austenitic steel under neutron irradiation conditions, the material functions of the thermal creep model implemented and verified in the framework of the certified software for numerical modeling of structural deformation under thermal and thermal radiation effects of UPAKS software are obtained and verified. The list of identifiable material functions of the thermal creep model includes: a function that characterizes the initial creep strain rate, referred to a unit stress level at a given temperature level and stress parameter; the radius of the creep surface, which is a function of temperature; the hardening function, characterizing the change in the initial creep rate from the hardening parameter at a given temperature; a function that takes into account the effect of a fast neutron flux on the creep rate at a given temperature. Using an analytical approximation of experimental data describing the rate of thermal creep of steels under neutron irradiation depending on the stresses, temperature, and flux of fast neutrons, we obtained relations for determining the values of all the functions of the thermal creep model. The value of the radius of the creep surface for a fixed temperature was determined from the condition that the creep deformation for a selected period of time and the neutron flux accumulated during this time will not exceed 0.2%. Using the UPAKS software, the creep model and the obtained material functions implemented in them, numerical simulation of the deformation of 1X18H10T steel under conditions of prolonged thermal load and neutron irradiation was performed. The results of numerical modeling are in good agreement with the analytical dependences that describe the creep of a given material under uniaxial SSS. A numerical creep simulation was also carried out under the assumption of the absence of neutron irradiation. As in the case of neutron irradiation, good agreement is obtained between the calculated and experimental data.

2013 ◽  
Vol 457-458 ◽  
pp. 185-190 ◽  
Author(s):  
Fu Qiang Yang ◽  
He Xue ◽  
Ling Yan Zhao ◽  
Jin Tian

The material constants calculation models for hyperbolic-sine creep model were proposed. The material constants used in hyperbolic-sine creep model for 316 stainless steel were calculated due to the models proposed and experimental data in the temperature range from 873K to 1023K. The relationships between material constants of 316 stainless steel creep model and temperature were obtained by curve fitting. The creep rate predict model of 316 stainless steel with only stress and temperature was also developed, the creep rates predicted were in good agreement with experimental data.


Author(s):  
N Khazraiyan ◽  
GH Liaghat ◽  
H Khodarahmi ◽  
N Dashtian-Gerami

In this article, a semi-analytical model has been developed for perforation of a hard projectile into a single- and two-layer concrete targets. The model is based on the dynamic cavity expansion theory and the reflection of compressive waves from the end of the concrete targets. The effect of friction coefficient is also investigated in the analysis. Numerical modeling of the problem has been performed in LS-DYNA code. Holmquist–Johnson–Cook, plastic kinematic, and rigid material models have been employed for the concrete, the backing plate, and the projectile, respectively. The impact velocity range, considered in this study, is between 300 and 800 m/s. No projectile erosion is considered in this velocity range. The analytical results of the investigation for both single- and two-layer concrete targets are in a good agreement with numerical simulations and experimental data.


2016 ◽  
Vol 817 ◽  
pp. 64-69
Author(s):  
Tatiana Vitenko ◽  
Paweł Droździel ◽  
Nazar Horodysky

This paper presents the results of numerical modelling of cavitation flows in a hydrodynamic module. The simulation was performed using the SolidWorks software package. The computations were made based on the Navier-Stokes equation combined with liquid state equations and empirical dependencies which define liquid parameters. The numerical results are in good agreement with experimental data.


1997 ◽  
Vol 1997 (1) ◽  
pp. 713-718 ◽  
Author(s):  
Michel C. Boufadel ◽  
Makram T. Suidan

ABSTRACT This paper investigates nutrient transport in a beach mesocosm operating under tidal action in the absence of waves. Numerical modeling results were compared to experimental data obtained from a tracer study on a mesocosm simulating a sand beach. Sodium chloride solution (simulating nutrient addition) was applied on the surface of the beach and was monitored at five locations in a 6.30-m length of sand plume. Both the numerical results and the experimental data agreed with findings from previously published data, where it was observed that the tracer plume moves downward and seaward and that the water table inside the beach is mostly above seawater level. Good agreement occurred between simulated water levels and observed levels; however, a mediocre fit was achieved between the simulated and the observed tracer concentrations because local variations existed in the saturated hydraulic conductivity, whereas the numerical model assumed a homogeneous domain. Implications of the results for bioremediation are discussed.


2020 ◽  
pp. 149-152

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .


1977 ◽  
Vol 5 (1) ◽  
pp. 6-28 ◽  
Author(s):  
A. L. Browne

Abstract An analytical tool is presented for the prediction of the effects of changes in tread pattern design on thick film wet traction performance. Results are reported for studies in which the analysis, implemented on a digital computer, was used to determine the effect of different tread geometry features, among these being the number, width, and lateral spacing of longitudinal grooves and the angle of zigzags in longitudinal grooves, on thick film wet traction. These results are shown to be in good agreement with experimental data appearing in the literature and are used to formulate guidelines for tread groove network design practice.


2015 ◽  
Vol 11 (3) ◽  
pp. 3224-3228
Author(s):  
Tarek El-Ashram

In this paper we derived a new condition of formation and stability of all crystalline systems and we checked its validity andit is found to be in a good agreement with experimental data. This condition is derived directly from the quantum conditionson the free electron Fermi gas inside the crystal. The new condition relates both the volume of Fermi sphere VF andvolume of Brillouin zone VB by the valence electron concentration VEC as ;𝑽𝑭𝑽𝑩= 𝒏𝑽𝑬𝑪𝟐for all crystalline systems (wheren is the number of atoms per lattice point).


1982 ◽  
Vol 14 (4-5) ◽  
pp. 253-256
Author(s):  
N Sriramula ◽  
M Chaudhuri

An investigation was undertaken on the removal of a model virus, bacterial virus MS2 against Escherichia coli, by sand filtration using untreated, and alum or cationic polyelectrolyte treated media, and uncoagulated as well as alum coagulated influent. Data on discrete virus removal were satisfactorily accounted for by electrokinetic phenomena and diffusion. For virus in association with turbidity, filter coefficients computed from experimental data were in good agreement with those predicted by mechanical straining and gravity settling which were the dominant mechanisms for removal of the turbidity particles to which the viruses attached.


2006 ◽  
Vol 4 ◽  
pp. 224-236
Author(s):  
A.S. Topolnikov

The paper is devoted to numerical modeling of Navier–Stokes equations for incompressible media in the case, when there exist gas and liquid inside the rectangular calculation region, which are separated by interphase boundary. The set of equations for incompressible liquid accounting for viscous, gravitational and surface (capillary) forces is solved by finite-difference scheme on the spaced grid, for description of interphase boundary the ideology of Level Set Method is used. By developed numerical code the set of hydrodynamic problems is solved, which describe the motion of two-phase incompressible media with interphase boundary. As a result of numerical simulation the solutions are obtained, which are in good agreement with existing analytical and experimental solutions.


Sign in / Sign up

Export Citation Format

Share Document