Influence Line Diagrams-I

1. Influence Line Diagrams-I Theory of Structures - I

2. Contents • Introduction • Influence lines for Beams • Reactions • Shear • Moments

3. Introduction • In normal shear force and bending moment diagrams, load remains static and cross-section of beam changes for various values.

4. In influence line diagrams for various functions (i.e. shear, bending moment, reactions), x-section remains static and load moves.

5. Influence lines for Beams 6 12 Unit load at x = 3 Unit load at x = 6 Unit load at x = 9 Unit load at x = 12 Unit load at x = 0 1 1 1 1 1 RA=1 RB=0 RA=0.75 RB=0.25 RA=0.5 RA=0.25 RA=0 RB=1 RB=0.5 RB=0.75 0.75 0. 5 0.25 + + + - - - 0.25 0. 5 0.75 3.0 2.25 2.25 1.5 1.5

7. 1.0 0.5 ILD for RA 0.5 ILD for Shear at 6 from A 3.0 1.0 ILD for Moment at 6 from A ILD for RB

8. Practice Problems • Example 6-1 to 6-8 • Chapter 6 • Structural Analysis by R C Hibbeler

9. Thank You