Investigation of Free Vibrations of Three-Layered Circular Shell Supported by Annular Ribs of Rigidity

2019 ◽  
Vol 968 ◽  
pp. 437-443
Author(s):  
Mykola Surianinov ◽  
Tetiana Yemelianova ◽  
Oleksii Shyliaiev
Keyword(s):  
Torsional Rigidity ◽  
Physical And Mechanical Properties ◽  
Free Vibrations ◽  
Layered Shell ◽  
Rigidity Parameter ◽  
Curvature Parameter ◽  
Properties Of Materials ◽  
Annular Rigidity ◽  
Light Weight Aggregate ◽  
Circular Shell

The construction of a mathematical model and the development of an algorithm of free vibrations investigation in the three-layered circular shell with a light-weight aggregate supported by annular rigidity ribs are considered in paper. The hypotheses of Kirchoff-Lyav are accepted for external bearing layers of shell and for aggregate there is accepted the linear law of tangential displacements change by thickness. The boundary conditions of a shell region closed between the ribs are established. Using the boundary transition, conditions along the lines of the ribs, taking into account and without deformations of displacement in the ribs, but without taking into account the torsional rigidity in the ribs are determined. The equation of motion of supported three-layered shell is obtained. The frequencies of free vibrations were investigated and values of parameter of the first frequency of free vibrations for a shell, supported by one and three rigidity ribs, were calculated. There are given values depending on the physical and mechanical properties of materials and geometric dimensions of the shell, the curvature parameter, and the rigidity parameter of an aggregate.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

scholarly journals Determination of geometric accuracy and surface roughness of small parts of circular and square sections, obtained depending on the printer location in the working space using selective laser melting technology from steel grade 12KH18N10T

2019 ◽  
pp. 59-67
Author(s):  
I. V. Gorbatov ◽  
Y. A. Orlov ◽  
V. A. Antiufeev ◽  
T. V. Telgerekova ◽  
N. Y. Orlova
Keyword(s):  
Selective Laser Melting ◽  
Physical And Mechanical Properties ◽  
Steel Grade ◽  
Geometric Accuracy ◽  
Laser Melting ◽  
Working Space ◽  
Properties Of Materials ◽  
Number Of Publications ◽  
Small Parts

The introduction of additive technologies for the manufacture of parts will significantly improve the efficiency and mobility of production. The technology of selective laser melting has the greatest accuracy in the manufacture of metal and alloyed parts. There are a number of publications on the physical and mechanical properties of such products, which often exceed the properties of materials obtained by traditional technology, but there is no data on the geometric accuracy of manufacturing. This paper provides explicit data on geometric accuracy, depending on various factors.

Magnesium-Silicon Substituted Carbonate Hydroxyapatite (Mg-Si CHA): Factors Affecting Sintering

2016 ◽  
Vol 694 ◽  
pp. 88-93
Author(s):  
Ahmad Fauzi Mohd Noor ◽  
Harmiza Zainudin
Keyword(s):  
Mechanical Properties ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Major Effect ◽  
Carbonate Content ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Complex Process ◽  
Powder Properties ◽  
Properties Of Materials

Sintering has major effect on the final properties of materials such as density, porosity and microstructure. Sintering of Mg-Si CHA in particular is a complex process since changes could occur during sintering, which include phase formation, grain size, pore size and carbonate content, and this in turn affects the mechanical properties. Improved mechanical properties of Mg-Si CHA is critical in load bearing implant applications. Poor control of thermal treatment of Mg-Si CHA during sintering would cause carbonate loss, leading to partial or total decomposition of Mg-Si CHA, subsequently would affect the physical and mechanical properties. The influence of powder properties (particle size, porosity, morphology) and sintering parameters (heating rate, firing atmosphere) on the sintered Mg-Si CHA microstructure was studied using scanning electron microscopy (SEM) characterization technique. The SEM results showed that we are able to produce sintered Mg-Si CHA without cracking of the compacted pellets, while keeping the carbonate level in the amount required (2 – 8%). X-Ray diffraction (XRD) was also performed on the sintered samples and the results indicated that a single phase Mg-Si-CHA was obtained, while Fourier transform infra-red (FTIR) spectroscopy result confirmed that as-synthesized Mg-Si CHA powder was a B-type.

Finite Element Simulation of Vacuum Hot Bulge Forming Process of Reactor Coolant Pump Rotor-Can

2011 ◽  
Vol 675-677 ◽  
pp. 909-912 ◽  
Author(s):  
Zhi Zhu ◽  
Li Wen Zhang ◽  
Dong Jiang Wu
Keyword(s):  
Finite Element ◽  
Physical And Mechanical Properties ◽  
Element Model ◽  
Forming Process ◽  
Coolant Pump ◽  
Creep Properties ◽  
Finite Element Software ◽  
Element Simulation ◽  
Properties Of Materials ◽  
Future Work

In this paper, a 2-D nonlinear thermo-mechanical coupled finite element model was developed to simulate the vacuum hot bulge forming process of rotor-can with the aid of finite element software MSC.Marc. Thermal physical and mechanical properties of materials vary with temperature in the model. In addition, the effects of high temperature creep properties of materials on the vacuum hot bulge forming process of rotor-can were considered. The temperature field, the stress-strain field and the displacement field of rotor-can during vacuum hot bulge forming process were calculated. This work is beneficial to understand the vacuum hot bulge forming process of rotor-can and lays a good foundation for future work.

Texture and Strain Experiments at OPAL

2010 ◽  
Vol 638-642 ◽  
pp. 2823-2828 ◽  
Author(s):  
Ulf Garbe ◽  
Oliver Kirstein ◽  
Andrew Studer ◽  
Vladimir Luzin ◽  
Klaus Dieter Liss
Keyword(s):  
Residual Stresses ◽  
New Technologies ◽  
Physical And Mechanical Properties ◽  
Local Variation ◽  
Inhomogeneous Deformation ◽  
New Materials ◽  
Destructive Analysis ◽  
Properties Of Materials ◽  
Non Destructive

In response to the development of new materials and the application of materials and components in new technologies the direct measurement, calculation and evaluation of textures and residual stresses has gained worldwide significance in recent years. Non-destructive analysis for phase specific residual stresses and textures is only possible by means of diffraction methods. The determination of global texture and the local variation of texture for example by inhomogeneous deformation are very important due to the coherence between the texture and the physical and mechanical properties of materials.

scholarly journals Damping of circular composite viscoelastic plate vibration under neutron irradiation

2020 ◽  
Vol 18 (4) ◽  
pp. 699-704
Author(s):  
Sergey Vakhneev ◽  
Eduard Starovoitov
Keyword(s):  
Neutron Irradiation ◽  
Sandwich Plate ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Viscoelastic Plate ◽  
Free Vibrations ◽  
Structural Elements ◽  
Natural Oscillations ◽  
Properties Of Materials ◽  
Initial Boundary Value

During the irradiation of structural elements with neutrons, ions, electrons, the mechanical properties of materials change. The neutron irradiation is of particular interest. Therefore, the relevance of the study is beyond doubt. The main purpose of this paper is to investigate the vibration damping of a circular composite viscoelastic plate under neutron irradiation. According to existing concepts, two mechanisms of accelerated radiation creep are possible. An initial-boundary value problem of free vibrations damping in a circular linearly viscoelastic sandwich plate under neutron irradiation is considered. It is determined that when the frequency of the perturbing force coincides with higher frequencies of natural oscillations, the periodicity is blurred, although the amplitude of oscillations increases and, in this case, a "false resonance" is observed. An analytical solution is obtained using the averaging method in dynamic viscoelasticity problems. The logarithmic decrement of oscillations is investigated numerically. Its dependence on the intensity of the neutron flux is revealed.

scholarly journals Caracterización de propiedades físico-mecánicas de rocas ígneas utilizadas en obras de infraestructura

2013 ◽  
Vol 3 (2) ◽  
pp. 129-139 ◽  
Author(s):  
M. Navarrete ◽  
W. Martínez Molina ◽  
E. M. Alonso-Guzmán ◽  
C. Lara-Gómez ◽  
J. A. Bedolla-Arroyo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Reliability ◽  
Physical And Mechanical Properties ◽  
Point Load ◽  
Load Test ◽  
Economical Method ◽  
Stone Materials ◽  
Properties Of Materials ◽  
Para Determinar ◽  
Almost All

RESUMENLos materiales pétreos se emplean actualmente en casi todos los procesos edificatorios y debido a esto se les realizan diferentes pruebas, pudiendo ser tanto físicas como mecánicas; en éstas, el ensayo de carga puntual normado por ASTM D 5731, describe el empleo del equipo Point Load para determinar la resistencia mecánica en rocas no labradas, con tamaño aproximado de 4 pulgadas de diámetro, determinándose características mecánicas con alta confiabilidad y facilidad; es método económico porque el equipo se puede llevar al sitio o (banco) cantera, no siendo necesario labrar los especímenes. Si además se realizan pruebas físicas como humedad actual, absorción, densidad y gravedad específica, estos resultados ayudan a conocer mejor el comportamiento mecánico de los materiales pétreos, pudiéndose lograr beneficios económicos reflejados en la elaboración del concreto, tanto hidráulico como asfáltico. En este trabajo también se comparan las propiedades físicas y mecánicas de los bancos de materiales de la región de Morelia, Michoacán, México.Palabras Clave: Materiales pétreos; Point Load; muestra no labrada.ABSTRACTStone materials are currently used in almost all building processes and because of this they perform different tests can be both physical and mechanical , in these, the load test regulated by ASTM D 5731 , describes the use of the instrument Point Load to determine the mechanical strength unhewn rocks , with approximate size of 4 inches in diameter , determining mechanical properties with high reliability and ease , it is economical method because the team can take the site or ( bank) quarry , not necessary till the specimens. If further tests are physical and current humidity, absorption, density, specific gravity, these results help to better understand the mechanical behavior of the stone, being able to achieve an economy, as in the preparation of concrete, hydraulically and asphalt. This paper also compares the physical and mechanical properties of materials banks in the region of Morelia, Michoacan, MexicoKeywords: stone materials; Point Load; sample worked.

scholarly journals MAGNETIC RESONANCE PROCESSING OF MATERIALS

2020 ◽  
Vol 3 (62) ◽  
pp. 29-38
Author(s):  
S. Kovalevskyy ◽  
◽  
O. Kovalevska ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Acoustic Waves ◽  
Permanent Magnets ◽  
Physical And Mechanical Properties ◽  
Natural Oscillations ◽  
White Noise Generator ◽  
Properties Of Materials ◽  
The Magnetic Field ◽  
Equal Amplitude

Acoustic devices for determining the elasticity modulus based on the measurement of the samples frequency resonant oscillation due to the sample exposure to acoustic waves with consistently changed frequencies. Objective: Development of an algorithm for increasing the hardness of materials due to magnetic resonance imaging. Materials and methods: The paper shows the possibility of using as a uniform flux to influence the volume of thematerial of the magnetic field formed by powerful permanent magnets. The process of influencing the volume of material of the experimental samples was that the effect of a uniform magnetic flux permeating the sample is initiated in a result of resonant oscillations of the sample caused by broadband exposure of equal amplitude using a “white noise” generator and a piezoelectric emitter. Results: Treatment of samples of materials placed in a uniform magnetic field, resonant polyfrequency vibrations with nanoscale amplitude in the range of 20...80 nm, allows you to change the viscosity of the material, the modulus of elasticity of the material and the hardness of material samples to improve the performance of these materials . Conclusions: Nanoscale amplitudes of natural oscillations of objects of complex shape in energy fields, which include uniform magnetic fields, can correct the physical and mechanical properties of materials of such objects in order to achieve their identity or add strictly defined properties.

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