1. Lecture #5
Trusses and frames.
Statically determinate trusses

2. USE OF TRUSS STRUCTURES IN AVIATION
Junkers F.13,
Germany, 1920 2

3. USE OF TRUSS STRUCTURES IN AVIATION
truss spar
beam spar
FFVS,
Sweden, 1942 3

4. USE OF TRUSS STRUCTURES IN AVIATION
Concorde,
Europe, 1969
truss spar
beam spar 4

5. USE OF TRUSS STRUCTURES IN AVIATION
Concorde,
Europe, 1969 5

6. USE OF TRUSS STRUCTURES IN AVIATION
Europe, 1972 6

7. USE OF TRUSS STRUCTURES IN AVIATION
Zenith CH701, 1986
motor mount frame 7

8. DIFFERENCE BETWEEN TRUSSES AND 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 8

9. DIFFERENCE BETWEEN TRUSSES AND FRAMES
Connection by riveting,
moment-resistant 9

10. DIFFERENCE BETWEEN TRUSSES AND FRAMES
Connection by welding,
moment-resistant 10

11. 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 11

12. Method of substitution of members
CONCLUSIONS
Method
of joints
Method of sections
Method of substitution of members
Effective for two-member joints
Effective when forces in few certain members should be determined
Used for complex structures; numerical methods should be considered as an alternative 12

13. … Internet is boundless …
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
Nice video on method of sections
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 … 13

14. Static determinacy. Methods of analysis
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.)” 14