Resistance of materials. Laboratory works. 4th edition

2016 ◽  
Author(s):  
Sergej Evtushenko ◽  
Viktor Logvinov
Keyword(s):  
International System ◽  
Statistical Processing ◽  
Physicomechanical Characteristics ◽  
Mechanics Of Materials ◽  
Ferrous Metals ◽  
System Of Units ◽  
Construction Mechanics ◽  
Steel Cast ◽  
Control Devices ◽  
And Control

Data on laboratory works on resistance of materials are provided, the assessment of errors of results of measurements and experiments is given, statistical processing of experimental data is in detail stated. The book contains information on nondestructive methods and control devices of characteristics and diagnostics of materials and designs. In a grant the International system of units (SI) (tab. 1 of the Appendix) is used, designations of sizes are accepted according to the international recommendations of ISO. Data on physicomechanical characteristics of steel, cast iron, non-ferrous metals, wood and polymers and the allowed tension for them are provided in tab. 2-8 of the Appendix. The grant is intended for the students studying courses of resistance of materials, mechanics of materials and designs, applied mechanics, construction mechanics and construction designs.

Dimensions of plane and solid angles and their units in the International System of Units (SI)

2020 ◽  
pp. 26-32
Author(s):  
M. I. Kalinin ◽  
L. K. Isaev ◽  
F. V. Bulygin
Keyword(s):  
Solid Angle ◽  
International System ◽  
International Committee ◽  
Plane Angle ◽  
Arc Length ◽  
Weights And Measures ◽  
International System Of Units ◽  
System Of Units ◽  
In Series ◽  
Solid Angles

The situation that has developed in the International System of Units (SI) as a result of adopting the recommendation of the International Committee of Weights and Measures (CIPM) in 1980, which proposed to consider plane and solid angles as dimensionless derived quantities, is analyzed. It is shown that the basis for such a solution was a misunderstanding of the mathematical formula relating the arc length of a circle with its radius and corresponding central angle, as well as of the expansions of trigonometric functions in series. From the analysis presented in the article, it follows that a plane angle does not depend on any of the SI quantities and should be assigned to the base quantities, and its unit, the radian, should be added to the base SI units. A solid angle, in this case, turns out to be a derived quantity of a plane angle. Its unit, the steradian, is a coherent derived unit equal to the square radian.

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