Week 6:Fabrication & Welded Connections

Question 1

List the 6 type of welds that are used to connect HSS members

Answer 1

1 Tack weld
2 Fillet weld (one-sided & double sided)
3 Joint penetration groove weld (complete & partial)
4 Flare groove welds
5 Flare bevel groove welds
6 Flare-V groove welds

Question 2

What are the methods of connecting HSS members?

Answer 2

1 Bolted connections
2 Nailed connections (linked to bolted)
3 Welded connections
4 Slotted plate connections (linked to welded)

Question 3

How many types of bolted connections did you learn about?

Answer 3

1 outside bolts
2 inside bolts
3 blind bolts
4 Flowdrill bolts

Question 4

When should the strength enhancement factor not be used in fillet weld design checks?

Answer 4

1 when one-sided fillet weld is used

2 when the connection is in tension or under bending

Question 5

What is the most important rule for detailing trusses?

Answer 5

Chord member should be a continuous member not intercepted by secondary members ie bracing

Question 6

Which type of truss K-connection is preferred by fabricators and why?

Answer 6

Gapped k-connection due to reduced cost of fabrication

Question 7

Which type of truss K-connection is preferred by designers and why?

Answer 7

Overlapped k-connection because of higher static, fatigue strength and reduced truss deflection

Question 8

Which method is best for bending HSS.

Answer 8

Hot bending

Question 9

Why is cold bending of HSS still utilised even though hot bending is the superior option?

Answer 9

-More econominal due to wide availability in North America

Question 10

What is profiling?

Answer 10

Cutting a HSS to the right bevelled edge so it can be connected seamlessly to another member

Question 11

What is an alternative to profiling HSS?

Answer 11

Partial of full flattening

Question 12

What 2 things could go wrong with flattening a HSS?

Answer 12

• reduces compressive strength if fully flattened

- member cracking

Question 13

What is the best way to flatten HSS?

Answer 13

Preheating to a dark red temperature and immediately flattening with a high-speed press

Question 14

What must be provided in the process of galvanising sealed HSS tubes?

Answer 14

Provide vent and drain holes

Question 15

List 3 ways to avoid liquid metal embrittlement during hot-dip galvanizing?

Answer 15

1- by using fully AL killed steel
2- increasing corner radii
3- testing a sample selection of the HSS tube before galvanising the entire member

Question 16

How do you avoid water pooling in HSS, expanding during winter and causing cracks?

Answer 16

seal all HSS after construction or provide drain holes

Question 17

What is CSA’s recommendation for minimum baseplate requirements for column stability during erection

Answer 17

All columns except small posts must be anchored to the foundation by at least 4 anchor rods/bolts

Question 18

List the 5 methods for inspecting HSS construction

Answer 18

• Visual inspection
• Magnetic particle inspection
• Inspection by liquid penetrant
• Radiographic examination
• Ultrasonic examination

Question 19

Explain why the yield line method is an upper bound method of plastic analysis of HSS connections?

Answer 19

Because it gives a solution greater than or equal to the plastic collapse load but less than the ultimate failure load