engineering

1. Fabrication
CE4101

2. Outlines
Fabrication
Fabrication: At shops and at sites
Welding Technology
Types of Welding
Supervision of Welded work
Non-destructive test (NDT)

3. 3
Fabrication
• Metal fabrication is the creation of metal structures by cutting, bending, and assembling
processes. It is a value-added process involving the creation of machines, parts, and
structures from various raw materials.
• Fabrication work is generally carried out at
shops but can be done at sites if suitable
mechanized facilities can be mobilized, and
experienced/qualified personnel assigned.
• Structural Steel is used widely in the
fabrication of structures for industrial or
nonindustrial structures, towers, stacks,
storage tanks, masts, bridges

4. Tower
Bridge Structure
Industrial building
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5. Fabrication of structural steel at shops and sites
• Fabrication of steel structure
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Shop Sites
 The quality of fabrication work at a shop
under totally controlled conditions would
definitely be better.
 Transportation of shop-fabricated
structures could pose problems.
 Adequate precautions would have to be
taken to eliminate deformation and damage
to the structure (end plate connection,
milled end surfaces)
 Site fabrication may eliminate the necessity
of the storage of structural members by
managing the construction of steel
structures.
 Transportation of site-fabricated structures
is less.
 Adequate precautions would have to be
taken to supervise and to maintain the site’s
fabricated structures.

6. Shop fabricated Specimens 6

7. 7
Shop fabricated Specimens

8. Real shop fabricated construction buildings in China 8

9. 9
Site fabricated Specimens

10. 10
Site fabricated Specimens

11. Site fabricated Specimens 11

12. Welding Technology
 Welding is the joining of pieces of metal at faces rendered plastic or liquid by raising the
temperature at the joint or by forging or under pressure.
 The basic function of welding is to provide links between atoms at the interface of the
joints.
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13. Types of Welding
 Cold-pressure welding
 Hot-pressure welding
 Friction welding
 Fusion welding
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 Flame welding
 Electro-slag welding
Manual metal arc (MMA) welding
Submerged arc (SAW) welding
Metal inert gas (MIG) welding
Tungsten inert gas (TIG) welding

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15. Supervision of welded work
 Regular inspection of welded structures is the
best way to assure product quality.
 During inspection, the supervisory personnel
look for weld defects. If defects are found,
they are adjudged on the basis of the estimate
of possible defects.
 Attention is paid to three aspects in visual
inspection
 1) Dimensions of the weld particularly in
welds
 2)Penetration in joints welded from one side
 3) Surface defects welded beam-to-column connection
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16. 16
NDT
• Dye-penetration Test
• Magnetic Particle Test
• Radiography
• Ultrasonic Inspection