Photo-Elastimetric Researches on Mechanical Engineering Problems

1923 ◽  
Vol 104 (1) ◽  
pp. 489-491
Author(s):  
E. G. Coker ◽  
John Dewrance
Keyword(s):  
Cross Section ◽  
Mechanical Engineering ◽  
Cutting Tools ◽  
Polarized Light ◽  
Large Cross Section ◽  
Thin Slice ◽  
Large Size ◽  
Engineering Problems ◽  
The Subject ◽  
Iceland Spar

In a former Graduates' Lecture delivered in 1913* the Lecturer described the general principles of Photo-Elasticity, and some applications to Engineering. The present Lecture was therefore devoted to a consideration of some developments of the subject which have taken place since, and attention was mainly directed to improvements in apparatus for photo-elastic investigation and to the results obtained by this method of research when applied to elucidate the action of cutting tools. A prime necessity in all such work is a beam of polarized light of large cross-section and considerable purity, and the scarcity of Iceland spar for Nicol's prisms of sufficiently large size has led to the use of other forms of polarizers, of which a very convenient one was described, consisting of a thin slice of Iceland spar suitably mounted between glass wedges, and provided with converging and diverging lens systems, whereby a beam of large cross-section and of great purity is obtained.

Mechanical Engineering Aspects of Naval Mining

1949 ◽  
Vol 160 (1) ◽  
pp. 22-32
Author(s):  
E. C. Wadlow
Keyword(s):  
Scientific Knowledge ◽  
Mechanical Engineering ◽  
Safety Requirements ◽  
Contact Type ◽  
Engineering Problems ◽  
The Subject ◽  
Considerable Complexity

The paper outlines some of the engineering problems which arise in connexion with naval mining, and describes some of the weapons and devices used by Britain and Germany in the war of 1939–45. Although naval mining has a long history, its development is necessarily conducted under conditions of secrecy, and publication of information concerning it is possible only after a major war in which there has been a general disclosure of methods and materials employed by both sides. The popular conception of a mine is a spherical buoyant object which will explode if hit by a ship. The buoyant contact type is, however, only one of many forms now available. A number of these are illustrated here, and the variety may surprise those not familiar with the subject. Methods of laying, general principles of operation, and safety requirements are described, and the mechanical details of design of mineshells, fittings, components for control and firing circuits, and other features are mentioned. Naval mines have reached a state of considerable complexity and many fields of scientific knowledge are now called upon in making them effective weapons.

Innovative Approach for Teaching Graphical Engineering Focused on CAD/CAM/CAE Systems

2013 ◽  
Vol 572 ◽  
pp. 311-314
Author(s):  
Juan Carlos Pérez-Cerdán ◽  
Miguel Lorenzo ◽  
Alejandro Reveriego ◽  
Carmen Blanco
Keyword(s):  
Design Process ◽  
Mechanical Engineering ◽  
Innovative Approach ◽  
Structural Components ◽  
New Approach ◽  
Engineering School ◽  
Engineering Problems ◽  
Cad Cam ◽  
The Subject ◽  
The University

A new approach of the teaching of the subject Graphical engineering is developed at the Engineering School of the University of Salamanca, focusing the contents on the use of the CAD/CAM/CAE systems as useful tools for applying engineering problems related with the mechanical engineering instead of describing diverse software options. Thus, the contents of the subject are divided into two blocks, one devoted to the analysis of the results of simulation of movement of diverse mechanisms and the second devoted to the analysis of diverse cases of loading structural components by means of FEA module, both available in the Autodesk Inventor Pro suite which can be downloaded free by the students. This way, students can visualize and realize of the complexity of a design process in engineering.

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

Analytical and High-Resolution EM Study of Crystalline Phases formed at Metal-Ceramic Interface

1990 ◽  
Vol 48 (2) ◽  
pp. 426-427
Author(s):  
N. Merk ◽  
A. P. Tomsia ◽  
G. Thomas
Keyword(s):  
Cross Section ◽  
Dissimilar Materials ◽  
Ceramic Materials ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Structural Applications ◽  
Metal Ceramic ◽  
The Subject ◽  
Ceramic Compounds ◽  
Scanning Electron

A recent development of new ceramic materials for structural applications involves the joining of ceramic compounds to metals. Due to the wetting problem, an interlayer material (brazing alloy) is generally used to achieve the bonding. The nature of the interfaces between such dissimilar materials is the subject of intensive studies and is of utmost importance to obtain a controlled microstructure at the discontinuities to satisfy the demanding properties for engineering applications . The brazing alloy is generally ductile and hence, does not readily fracture. It must also wett the ceramic with similar thermal expansion coefficient to avoid large stresses at joints. In the present work we study mullite-molybdenum composites using a brazing alloy for the weldment.A scanning electron micrograph from the cross section of the joining sequence studied here is presented in Fig. 1.

Light microscopy of ceramics

1993 ◽  
Vol 51 ◽  
pp. 908-909
Author(s):  
Walter C. McCrone
Keyword(s):  
Refractive Index ◽  
Light Microscopy ◽  
Light Microscope ◽  
Polarized Light ◽  
Refractive Indices ◽  
Complete Coverage ◽  
The Subject ◽  
Lower Refractive Index

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).

Air exchange dynamics in the system of large cross-section blind roadways

2020 ◽  
Vol 2 ◽  
pp. 46-57
Author(s):  
S.V. Maltsev ◽  
◽  
B.P. Kazakov ◽  
A.G. Isaevich ◽  
M.A. Semin ◽  
...  
Keyword(s):  
Cross Section ◽  
Large Cross Section ◽  
Air Exchange

scholarly journals Are We Able to Print Components as Strong as Injection Molded?—Comparing the Properties of 3D Printed and Injection Molded Components Made from ABS Thermoplastic

2021 ◽  
Vol 11 (15) ◽  
pp. 6946
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Wiktor Rozpiórski ◽  
Marcin Słoma
Keyword(s):  
Tensile Strength ◽  
Injection Molding ◽  
Mechanical Strength ◽  
Cross Section ◽  
Fused Deposition Modeling ◽  
High Strength ◽  
Large Cross Section ◽  
Fused Deposition ◽  
Injection Molded ◽  
The Cross

In this paper, we are focusing on comparing results obtained for polymer elements manufactured with injection molding and additive manufacturing techniques. The analysis was performed for fused deposition modeling (FDM) and single screw injection molding with regards to the standards used in thermoplastics processing technology. We argue that the cross-section structure of the sample obtained via FDM is the key factor in the fabrication of high-strength components and that the dimensions of the samples have a strong influence on the mechanical properties. Large cross-section samples, 4 × 10 mm2, with three perimeter layers and 50% infill, have lower mechanical strength than injection molded reference samples—less than 60% of the strength. However, if we reduce the cross-section dimensions down to 2 × 4 mm2, the samples will be more durable, reaching up to 110% of the tensile strength observed for the injection molded samples. In the case of large cross-section samples, strength increases with the number of contour layers, leading to an increase of up to 97% of the tensile strength value for 11 perimeter layer samples. The mechanical strength of the printed components can also be improved by using lower values of the thickness of the deposited layers.

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