Transcript Method of sections

Lecture #5
Trusses and frames.
Statically determinate trusses
USE OF TRUSS STRUCTURES IN AVIATION
Junkers F.13,
Germany, 1920
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USE OF TRUSS STRUCTURES IN AVIATION
truss spar
beam spar
FFVS,
Sweden, 1942
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USE OF TRUSS STRUCTURES IN AVIATION
Concorde,
Europe,
1969
truss spar
beam spar
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USE OF TRUSS STRUCTURES IN AVIATION
Concorde,
Europe,
1969
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USE OF TRUSS STRUCTURES IN AVIATION
A300,
Europe,
1972
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USE OF TRUSS STRUCTURES IN AVIATION
Zenith CH701, 1986
motor mount frame
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DIFFERENCE BETWEEN TRUSSES AND FRAMES
Trusses
Frames
Members are subjected
to tension/compression
only
At least one member is
subjected to bending,
shear or torsion
Composed of rods
Composed of bars
Usually more simple to
calculate, more weight
effective
Usually more simple to
manufacture, and to
place in tight layout
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DIFFERENCE BETWEEN TRUSSES AND FRAMES
Connection by riveting,
moment-resistant
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DIFFERENCE BETWEEN TRUSSES AND FRAMES
Connection
by welding,
momentresistant
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TOPIC OF THE LECTURE
Methods of forces calculation:
•Method of joints
•Method of sections
•Method of substitution of members
Supplementary tools:
•Zero-force member identification
•Principle of superposition
•Use of symmetry
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CONCLUSIONS
Method
of joints
Method of
sections
Method of
substitution of
members
Used for
Effective when
complex
forces in few
structures;
Effective for twocertain members
numerical
member joints
should be
methods should
determined
be considered as
an alternative
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WHERE TO FIND MORE INFORMATION?
Method of joints and method of sections are covered in
A. Kassimali. Structural Analysis. 2009,
Chapters 4.5 and 4.6
Nice video on method of joints
http://www.youtube.com/watch?v=-qms9xt3sbQ
Nice video on method of sections
http://www.youtube.com/watch?v=Yn-9voH1gZ4
Principle of superposition and method of substitution of
members are covered in
A. Williams. Structural Analysis In Theory and Practice. 2009,
Chapters 1.7, 2.4
… Internet is boundless …
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TOPIC OF THE NEXT LECTURE
Static determinacy. Methods of analysis
All materials of our course are available
at department website k102.khai.edu
1. Go to the page “Библиотека”
2. Press “Structural Mechanics (lecturer Vakulenko S.V.)”
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