Lecture #5 Trusses and frames. Statically determinate trusses.

Lecture #5Trusses and frames. Statically determinate trusses

USE OF TRUSS STRUCTURES IN AVIATION

2

Junkers F.13,Germany, 1920

USE OF TRUSS STRUCTURES IN AVIATION

3

FFVS,Sweden, 1942

truss sparbeam spar

USE OF TRUSS STRUCTURES IN AVIATION

4

truss sparbeam spar

Concorde,Europe, 1969

USE OF TRUSS STRUCTURES IN AVIATION

5

Concorde,Europe, 1969

USE OF TRUSS STRUCTURES IN AVIATION

6

A300,Europe, 1972

USE OF TRUSS STRUCTURES IN AVIATION

7

Zenith CH701, 1986

motor mount frame

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

9

Connection by riveting,moment-resistant

DIFFERENCE BETWEEN TRUSSES AND FRAMES

10

Connection by welding,moment-resistant

TOPIC OF THE LECTURE

11

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

CONCLUSIONS

Method

of jointsMethod 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

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WHERE TO FIND MORE INFORMATION?

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Method of joints and method of sections are covered inA. Kassimali. Structural Analysis. 2009,Chapters 4.5 and 4.6

Nice video on method of jointshttp://www.youtube.com/watch?v=-qms9xt3sbQNice video on method of sectionshttp://www.youtube.com/watch?v=Yn-9voH1gZ4

Principle of superposition and method of substitution of members are covered inA. Williams. Structural Analysis In Theory and Practice. 2009,Chapters 1.7, 2.4

… Internet is boundless …

TOPIC OF THE NEXT LECTURE

14

Static determinacy. Methods of analysis

All materials of our course are availableat department website k102.khai.edu

1. Go to the page “Библиотека”2. Press “Structural Mechanics (lecturer Vakulenko S.V.)”