Download presentation

Presentation is loading. Please wait.

1
**CIVL3310 STRUCTURAL ANALYSIS**

Chapter 7: Approximate Analysis of Statically Indeterminate Structures CIVL3310 STRUCTURAL ANALYSIS Professor CC Chang

2
Approximate Analysis Preliminary analysis for complex indeterminate structures Involve some assumptions & different answers are possible

3
**Structural Analogy C=T=67.5 kN FBK=37.5 kN**

20 kN 20 kN 20 kN 20 kN 20 kN 12 m m= 54 m 50 kN Shear (kN) moment (kN∙m) C=T=67.5 kN V=30 kN 12 m M=810 kN∙m Fy=30 kN FBK=37.5 kN

4
**Structural Analogy 3 degrees of indeterminacy P1 P2 R1 R2**

Stiff diagonal members assume Fa=Fb Weak diagonal members assume Fb=0 (no compression)

5
Example 7.1 Determine (approximately) the forces in the members of the truss. The diagonals are designed to support both tensile and compressive forces

6
Inflection Points Points of zero moment: internal hinges (Deflection shape: zero curvature)

7
Inflection Points Clamped BC Under UDL

8
Inflection Points Assumed clamped Location: 0.2L

9
Inflection Points 0.2L 0.2L L

10
**Frames under Vertical Loads**

11
**Frames under Vertical Loads**

12
Example 7.3 Determine (approximately) the moment at the joints E and C.

13
**Frames under Horizontal Loads**

Inflection point 1 degree indeterminacy hinge

14
**Frames under Horizontal Loads**

15
**Frames under Horizontal Loads**

16
Example 7.4 Determine (approximately) the forces acting in the members of the Warren portal.

17
**Frames under Horizontal Loads**

Portal method Inflection points Shear forces

18
**Frames under Horizontal Loads**

Cantilever method Inflection points Axial forces

19
**7. Approximate Analysis Structural analogy What are inflection points?**

How to analyze frames under vertical loads? How can inflection points be used to simplify the analysis? What are portal method and cantilever method?

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google