scholarly journals Physical Insights Into Cylindrical Illusion Device With Isotropic and Homogeneous Materials

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 26468-26477
Author(s):  
Zhenzhong Yu ◽  
Zhong Yang ◽  
Yan Zhang ◽  
Xingliu Hu ◽  
Yizhi Wang
Keyword(s):  
Homogeneous Materials

A study of indentation work in homogeneous materials

2006 ◽  
Vol 21 (6) ◽  
pp. 1363-1374 ◽  
Author(s):  
Mengxi Tan
Keyword(s):  
Plastic Deformation ◽  
Elastic Modulus ◽  
Elastic Energy ◽  
Size Effects ◽  
Unit Volume ◽  
Plastic Work ◽  
Total Work ◽  
Indentation Size ◽  
Scaling Relationships ◽  
Homogeneous Materials

The work of indentation is investigated experimentally in this article. A method of using the elastic energy to extract the elastic modulus is proposed and verified. Two types of hardness related to the work of indentation are defined and examined: Hwtis defined as the total work required creating a unit volume of contact deformationand Hwp is defined as the plastic work required creating a unit volume of plastic deformation; experiments show that both hardness definitions are good choices for characterizing hardness. Several features that may provide significant insights in understanding indentation measurements are studied. These features mainly concern some scaling relationships in indentation measurements and the indentation size effects.

Computational and Experimental Studies of Cellular Samples Manufactured Using Additive Methods for Use in Advanced Lightweight Designs of Engine Parts

2020 ◽  
Author(s):  
Liubov Magerramova ◽  
Michael Volkov ◽  
Oleg Volgin ◽  
Pavel Kolos
Keyword(s):  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Cell Structure ◽  
Experimental Studies ◽  
Cellular Structures ◽  
Uniaxial Tensile ◽  
Porous Structures ◽  
Lattice Cell ◽  
Cell Structures ◽  
Homogeneous Materials

Abstract The use of cellular structures is one way to reduce the weight of engine parts. Cellular structures are used to provide rigidity and strength for parts subject to compression, bending, and shock loads. Failure of the individual elements of a lattice/cell structure does not result in the destruction of the entire part; this stands in contrast to the structure of a conventional homogeneous metal object, in which cracks will continue to increase with increasing load, causing the destruction of the entire part. Lattice/cell structures have relatively high characteristics of rigidity and strength, excellent thermal insulation properties, energy absorption characteristics, and high fatigue resistance. The use of this type of structure in engine part construction opens up new opportunities for advanced aviation applications. However, the deformation behavior of porous and metallic structures differs significantly from that of conventional homogeneous materials. Samples with cellular and porous structures are themselves designs. Therefore, procedures for strength testing and interpretation of experimental results for cellular and porous structures differ from those for samples derived from homogeneous materials. The criteria for determining the properties of cellular structures include density, stiffness, ability to accumulate energy, etc. These parameters depend on the configuration of the cells, the size of each cell, and the thickness of the connecting elements. Mechanical properties of cellular structures can be established experimentally and confirmed numerically. Special cellular specimens have been designed for uniaxial tensile, bending, compression, shear, and low-cycle fatigue testing. Several variants of cell structures with relative densities ranging from 13 to 45% were considered. Specifically, the present study examined the stress-strain states of cell structures from brands “CobaltChrome MP1” powder compositions obtained by laser synthesis on an industrial 3D printer Concept Laser M2 Cusing Single Laser 400W. Numerical simulations of the tests were carried out by the finite element method. Then, the most rational cellular structures in terms of mass and strength were established on the basis of both real and numerical experiments.

scholarly journals Theoretical and experimental method for determining elastic characteristics of nanomaterials

2019 ◽  
Vol 489 (5) ◽  
pp. 469-472
Author(s):  
V. M. Fomin ◽  
A. A. Filippov
Keyword(s):  
Mechanical Characteristics ◽  
Heterogeneous Material ◽  
Uniaxial Stress ◽  
Analytical Form ◽  
Mechanical Tests ◽  
Stress And Strain ◽  
Binder Phase ◽  
Homogeneous Materials ◽  
Silica Dioxide ◽  
Elastic Characteristics

The method allows determining the mechanical characteristic of nanoobjects was presented. A heterogeneous material consisting of a nanophase and a binder phase was considered, the mass and volume concentrations of components were given. Heterogeneous material is reduced to homogeneous by averaging methods while the mechanical characteristics will be associated with averaged ones. Assuming that the mechanical characteristics of the binder and averaged homogeneous materials are known from mechanical tests, the system of equations allow us to determine the mechanical characteristics of nanoobjects included in this heterogeneous material. It is believed that the mechanical characteristics of bonding and averaged homogeneous materials make it possible to obtain equations of equations that allow one to determine the mechanical characteristics of nano-objects present in this heterogeneous material. Classical mechanical tests were carried out, describing the uniaxial stress and strain states of materials, which made it possible to obtain an analytical form the dependences of the mechanical characteristics of nanophases depending on their size. Specific examples are given for silica dioxide nanoparticles (Aerosil and Tarkosil powders).

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