CHAPTER 7 - SHEET METAL BENDING

Question 1

INTRODUCTION
What would happen if a sheet of aluminium alloy was bent around a square corner?

Answer 1

It would cause the material to crack

Question 2

INTRODUCTION
What does the method of bend allowance used for?

Answer 2

To calculate the (developed) length of flat sheet metal required to make a bend f a specific radius and angle

Question 3

INTRODUCTION
What does the bend allowance calculation account for?
(RAT)

Answer 3

Thickness of the sheet metal
Bend radii
Bend angle

Question 4

INTRODUCTION
When produces a band what forces are happening on the outside, and on the inside of the neutral bend axis?

Answer 4

Outside of the neutral bend = Tension
Inside of the neutral bend = Compression

Question 5

BEND CALCULATION
State the calculation for the length of an arc of 90 degrees..
(thickness is ignored)

Answer 5

Length = 2 x Pi x r x 90/360

Question 6

BEND CALCULATION
State the calculation for the Length of a Bend..
(Thickness is a factor)

Answer 6

L = 2 x Pi x (r + t/2) x 90/360

Question 7

BEND CALCULATION
In the length of bend calculation, where thickness is a factor, how does the location of the radii given, effect the calculation?

Answer 7

If the radius is on the INSIDE of the bend, then the half material thickness is ADDED

If the radius is on the OUTSIDE of the bend, then the half material thickness is SUBTRACTED

Question 8

BEND CALCULATION
What is the “developed length”?

Answer 8

This is when the allowance of each bend has been calculated and the dimensions drawn out on the metal

Question 9

BEND CALCULATION
What does a sighting line help accomplish?
Ensures the centre of the bend occurs in the correct position

Answer 9

Ensures the centre of the bend occurs in the correct position