The beam column connection is often one of the most vulnerable locations in a structure due to the way the energy is transferred through the connection, this is even more so when the structure is subjected to seismic loading. The following presentation proposes a friction device that can be retrofit to the beam column connection in the hopes it will dissipate some of the energy induced through the seismic loading.

1. Energy Absorbing Beam-
Column Connections
BEB801 – Project 1
Keagan Leamy n8329559

2. Presentation Overview
• Problem Overview
• Research Background
• Concrete Connection Types
• Energy Dissipation Devices
• Proposed System
• Model
• Loading
• Results
• Conclusion

3. Problem Overview
Beam-Column connections are vulnerable locations in a structure, especially
under seismic loading.
𝐹 𝑡 = 𝑀 𝑢 + 𝐶 𝑢 + 𝐾 𝑢
Dynamic Energy = Energy to Vibrate Structure + Energy absorbed + Energy to
deform structure
Aim to increase energy absorbed, reducing energy to vibrate and deform
structure

4. Cyclic Loading
Boundary Conditions used for Seismic Loading, Cantilever
Column (Xue & Zhang, 2014)

5. Concrete Connection Types
• Monolithic Cast-In-Place
• Precast
• Ductile Connection
• Moment Connection
• Composite Beams

6. Monolithic Cast-In-Place
Example Reinforced Concrete Connection Geometry and
Steel Layout (Li & Pan, 2004)

7. Monolithic Cast-In-Place
Typical Failure mode and Flexural Cracks of a Monolithic Connection
(Parastesh, Hajirasouliha, & Ramezani, 2014)
Flexural Cracks began to form in both column and beam at half theoretical ultimate load

8. Precast - Ductile
Example Precast Ductile Connection Geometry and Steel
Layout (Khaloo & Paratesh, 2003)

9. Precast - Ductile
Typical Failure mode and Flexural Cracks of a Precast
Ductile Connection (Khaloo & Paratesh, 2003)
Connection prevented
crack propagation
from beam to column

10. Precast - Moment
Example Precast Moment Connection Geometry and Steel
Layout (Parastesh, Hajirasouliha, & Ramezani, 2014)

11. Precast - Moment
Typical Failure mode and Flexural Cracks of a Precast Moment
Connection (Parastesh, Hajirasouliha, & Ramezani, 2014)
Cracks occurred at connection zone, preventing flexural cracks to form in beam

12. Composite Beams
Example Composite Beam Column Geometry and Steel Layout
(Xue & Zhang, 2014)

13. Composite Beams
Typical Failure mode
and Flexural Cracks of
a Composite Beam
Section (Xue & Zhang,
2014)
Severe Cracking due to
neutral axis being closer to
slab.
Performance very similar to
cast-in-place systems

14. Energy Dissipation Devices
• Friction Damper
• Shear Links
• Viscoelastic Damper

15. Energy Dissipation Devices
Idealised Hysteresis Loops of Energy Dissipation Devices (Constantinou, Soong, & Dargush, 1998)

16. Friction Damper
Prototype Friction Damper (Morgen & Yahya, 2004)
Designed to aid with gap
opening behaviour of post
tensioned pre cast beams.
Increased energy dissipation of
specimen significantly.

17. Friction Damper
Simplified Numerical Model for Friction Damper (Valente,
2013)
Energy Dissipated by
structure decreased as
energy dissipation was
concentrated in device.
This reduced the plastic
demand of the structure.

18. Shear-Links
Schematic Diagram of an Aluminium Shear Link Included
into a Chevron-type OCBF (Rai & Wallace, 1998)

19. Viscoelastic Damper
Picture of Viscoelastic-Wall Dampers (Liu, Wang, & Ren,
2015)

20. Proposed System

21. Proposed System

22. Proposed System - Control
Parameter Value
Stiffness: 𝒌 =
𝟏𝟐𝑬𝑰
𝑳 𝟑 = 0.527 × 106
𝑁/𝑚𝑚
Mass (kg) 6932.2kg
Circular Frequency of Vibration: 𝝎 =
𝒌
𝒎
(rad/sec)
= 8.72𝑟𝑎𝑑/𝑠𝑒𝑐
Period of Vibration: 𝑻 =
𝟐𝝅
𝝎
(sec) 0.72sec
Frequency: 𝒇 =
𝟏
𝑻
1.4 Hz

23. Proposed System - Control
-1.5
-1
-0.5
0
0.5
1
1.5
0 1 2 3 4 5 6 7
Force(kN)
Time (s)
Force vs Time Graph

24. Proposed System - Control

25. Proposed System - Device
Variable Parameter Value
Breadth b (mm) 450
Thickness d (mm) 40
Length L (mm) 270
Mass (kg) 38.151
Young’s Modulus E (Mpa) 200 000
Second Moment of
Area 𝐼 =
𝑏𝑑3
12
(𝑚𝑚4
)
2.4 × 106
Axial Stiffness
=
𝐴𝐸
𝐿
(𝑁/𝑚𝑚)
13.333 × 106
Lateral Stiffness
=
12𝐸𝐼
𝐿3
(𝑁/𝑚𝑚)
0.293 × 106

26. Proposed System - Device

27. Proposed System - Results

28. Proposed System - Results
-15
-10
-5
0
5
10
15
0 1 2 3 4 5 6 7
Displacement(mm)
Time (sec)
Comparrison in Displacement vs Time with and without Device
Control Device

29. Proposed System - Results
-30
-20
-10
0
10
20
30
-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4
Force(kN)
Displacement (mm)
Hysterises Loop For Device

30. Conclusion