Defining a Flange Type

Figure 1:24. Figure showing a folded flange after bending.

Suppose that we want to calculate the width of the flange before bending, FLA_W. This means that we want to calculate the length of the dashed line, which is the neutral line in bending.

Make the following assumptions:

• H is the nominal height of the flange, as given by the user. Here it is supposed to be the total height after bending.

• The neutral line is on the depth 1/3 of the material thickness.

Then FLA_W is calculated:

that means,:

Now we want to calculate the position of the marking line, MARK_D. Make the following assumptions:

• The bending should start at the base line of the flange.

• The bending tool is to be placed in the midpoint of the arc.

• The neutral line is on the depth 1/3 of the material thickness.

Then

MARK_H = 2*PI*(R + T/3)/8 = (PI/4)*R + (PI/12)*T

that means,:

Assume that the bending radius is 30, and we want to refer to the flange type as number 10. Then our flange type could be defined with the statement:

FLA_TYPE, 10
  /RADIUS     =30
  /W_H_FACT   = 1
  /W_RAD_FACT = 0.571
  /W_T_FACT   = -0.476
  /M_RAD_FACT = 0.785
  /M_T_FACT   = 0.262;