Neutral Factor Sheet Metal

I had a question on k factors for our 3 d modeling software.

Neutral factor sheet metal.

The k factor in sheet metal working is the ratio of the neutral axis to the material thickness. Flat blank dimensions are calculated by determining the path length along the neutral axis. It is the fraction of material thickness from the inside of the bend to the neutral axis. The location of the neutral axis is specified with the k factor.

The location of the neutral axis varies and is based on the material s physical properties and its thickness. The k factor is a constant determined by dividing the material thickness of the sheet by the location of the neutral axis. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. In sheet metal design the k factor is used to calculate how much sheet metal one needs to leave for the bend in order to achieve particular final dimensions especially for between the straight sides next the bend.

Our design engineers typically use a factor of 0 4 for our air formed press brake parts. Use the known k factor and the known inner bending radius to calculate the bending radius of the neutral line. The line where the transition from compression to stretching occurs is called the neutral axis. Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness.

To calculate the bend allowance the k factor and the derived coefficient called the y factor insert the thickness and initial length of the sheet into the cells on the left. The k factor is the ratio of the neutral axis location t to the material thickness mt. Bending angle is 90. After bending the sheet insert the inner radius and flanges a and b.

The neutral axis does not suffer any change of length during a bending operation. K factor a constant determined by dividing the thickness of the sheet by the location of the neutral axis which is the part of sheet metal that does not change length. The area within the sheet defined as the neutral axis does not get compressed on the inside of the neutral axis or expanded on the outside. For example the following part that has a 90 o bend.

When you bend sheet metal the neutral axis shifts toward the inside surface of the bend. K factor in sheet metal bending is a constant used to calculate sheet metal flat length or flat pattern.