ALL ABOUT THE TYPES OFF CONNECTION IN STEEL STRUCTURE HELPFUL FOR DIPLOMA AND DEGREE CIVIL ENGINEERING STUDENTS

1. DESIGN OF CONNECTIONS IN
STEEL STRUCTURE
B.E. CIVIL ENGINEERING
TITLE OF THE TOPIC
Prepared by: DEVANG ONDHIYA
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2. Connection
• Connections are structural
elements used for joining different
members of a structural steel frame
work.
• Steel Structure is an assemblage of
different member such as
“BEAMS,COLUMNS” which are
connected to one other, usually at
member ends fasteners , so that it
shows a single composite unit.

3. Component of connection
• Bolts
• Weld

4. • Connecting Plates
• ConnectingAngles

5. Classification of connection
• On the Basis of Connecting Member.
• According to the type of internal forces.
• According to the type of structural Elements
• According to the type of members joining

6. On basis of connecting members
• Riveted Connections
• Bolted Connections

7. • Welded Connections
• Bolted-Welded Connections

8. Riveted connection
• Used for very long time.
• Made up of:
 Round Ductile steel bar called shank.
 A head at one end
• The length of the rivet should sufficient to form the
second head.
• Design -very similar to bearing type of bolted
connection.

9. Installation
• Heating of the rivet
• Inserting it to an oversize hole pressure
to the head.
• Squeezing the plain End by Pneumatic
driver Round head.
• On Cooling Reduces in Length–
Clamping Force

10. Why riveting is no longer used?
• The introduction of high strength structural bolts.
• The labour costs associated with large riveting
crews
• The cost involved in careful inspection and removal
of poorly installed rivets.
• The high level of noise associated with driving
rivets.

11. Bolted connection
• Bolts may be loaded in:
 Tension / shear or both tension
and shear
• Threads of bolts under shear force:
 Excluded – Increased strength
 Included-Decreased strength

12. Types of bolt
• Bearing type bolts
• High strength friction grip
bolts (HSFG)

13. 1. Black Bolts
• The most common type is
bearing bolts in clearance holes,
often referred to as Black Bolts.
• Ordinary, unfinished, rough, or
common bolts.
• Least Expensive
• Primarily - Light structures
under static load such as small
trusses, purlins etc

14. 2. Turned Bolts
• Similar to unfinished bolts.
• Shanks - Hexagonal Rods
• Primarily - Light structures under
static load such as small trusses,
purlins etc
• Expensive – Limited use –
Structures with no Slippage
Connections

15. 3. Ribbed Bolts
• Round head similar to Rivets.
• Raised ribs parallel to the shank.
• Actual Diameter - slightly Larger
than the hole
• Tightly fit into the hole.
• Popular - Economical in Material
& Installation

16. High strength friction grip (HSFG)
• Uses when bearing type bolts slips
under shear
• High strength bolts (8G or 10K
grade) Pre-tensioned against the
plates to be bolted together so that
contact pressure developed between
the plates being joined
• Prevents relative slip when extra
shear is applied
• Higher Shear Resistance

17. Advantages of bolted connection
• The bolting operation is very silent
• Bolting is a cold process hence there is no risk of fire
• Bolting operation is more quicker than riveting.
• Less man power is required in making the
connections

18. Disadvantages of bolted connection
• If subjected to vibratory loads, results in reduction
in strength get loosened.
• Unfinished bolts have lesser strength because of
non uniform diameter

19. Welded connection
• whose components are joined together primarily by
welds
• Types of weld
Groove ( More reliable than others)
Fillet (Mostly used, Weaker than groove and others)
Plug (expensive – poor transmission of tensile
forces)
Slot (expensive - poor transmission of tensile forces)
Plug and Slot welds – stitch different parts of
members together.

20. Groove weld

21. Fillet weld

22. Plug weld

23. Slot weld

24. Advantages of welded connection
• Economical – Cost of materials and labors.
• Efficiency is 100% as compared to rivets (75- 90%)
• Fabrication of Complex Structures – Easy – like
Circular Steel pipes.
• Provides Rigid Joints – Modern Practice is of
Rigid Joints.

25. Disadvantages of welded connection
• No provision for expansion or contraction therefore
greater chances of cracking.
• Uneven heating and cooling - member may distort
may result in additional stresses.
• Inspection is difficult and more costlier than rivets

26. Bolted-welded connection
• Most connections are Shop
Welded and Field Bolted types.
• More Cost Effective
• Better Strength & Ductility
characteristics than Fully welded

27. According to the type of internal forces
Shear (semi rigid, simple) connections
• Allows the beam end
to rotate without a
significant restraint.
• Transfers shear out of
beam

28. Moment (rigid) connections
• Designed to resist both
Moment and Shear.
• Often referred - rigid or
fully restrained
connections
• Provide full continuity
between the connected
members
• Designed to carry the full
factored moments.

29. According to the type of structural elements
• Single plate angle Connections
• Double web angle connections
• Top and seated angle connections
• Seated beam connections

30. Single plate angle connections
Two Step Process
• A plate is welded to
secondary section (beam)
• An Angle is welded to
Primary Section (column or
Beam)
• Single shear plate welded to
secondary beam and bolted
to Primary beam or column

31. Double web angle connections
• Two angles welded or
shop bolted to the web
of a secondary beam.
• After erection the
angles are bolted or site
welded to the primary
member (beam or
column).

32. Top and seated angle connections
•Generally used in case of
moment connections.
•Two angles are provided at top
and bottom of the beam to
resist moment.
•Generally used for lesser
moments where heavy loads
are not acting

33. Seated beam connections
•Generally used in case
of shear connections.
•A seating angle - at
bottom of secondary
beam - shop welded to
the primary member.
•Seating angle resists
vertical shear coming
from the beam

34. According to the type of members joining
• Beam to beam connections
• Column to column connections (column splices)
• Beam to Column Connections
• Column Base Plate Connections

35. Beam to beam connections

36. Column to column connections (column
splices)
•Connects column to column.
•Column splice comes under
this category.
•Used to connect column
sections of different sizes.

37. Beam to Column Connections
• Connects Beam to column.
• Very Common
• Beams are normally attached
using two or more bolts
through the web.

38. Column Base Plate Connections
• Steel plates placed at the bottom of Columns.
• Function : to transmit column loads to the
concrete pedestal.

39. • A layer of grout should be placed between the base
plate and its support for the purpose of levelling.
• Anchor bolts should be provided to stabilize the
column during erection or to prevent uplift.