Neutral Axis In Sheet Metal

During sheet metal bending.

Neutral axis in sheet metal.

I had a question on k factors for our 3 d modeling software. Given a thickness of 0 1345 that distance calculates to nan 0 1345 x. The line where the transition from compression to stretching occurs is called the neutral axis or the neutral sheet. Bending is a manufacturing process that produces a v shape u shape or channel shape along a straight axis in ductile materials most commonly sheet metal.

The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. Inside bend surface is compressed whereas the outer bend surface is stretched. The theoretical line of the neutral axis will remain the same length both before and after the bend is complete. The line where the transition from compression to stretching occurs is called the neutral axis.

The bend deduction sometimes called the bend compensation describes how much the outside of the sheet has been stretched. The neutral axis is a theoretical area lying at 50 percent of the material thickness while unstressed and flat. Somewhere in between the thickness of material lies neutral axis. In sheet metal bending process when metal is bent the material along the inner bend radius is going to undergo compression and the material along the outer bend radius will be stretched.

Our design engineers typically use a factor of 0 4 for our air formed press brake parts. Now let s take a look at an example of k factor. The k factor in sheet metal working is the ratio of the neutral axis to the material thickness. In other words the neutral axis for this part occurs nan of the way through the material s thickness.

Neutral axis is a line where material is neither compressed or stretched. Commonly used equipment include box and pan brakes brake presses and other specialized machine presses typical products that are made like this are boxes such as electrical enclosures and rectangular ductwork. When you bend sheet metal the neutral axis shifts toward the inside surface of the bend. The location of the neutral axis varies and is based on the material s physical properties and its thickness.

Let s presume you are creating a sheet metal part in solidworks. That is it shifts toward the inside of the bend. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. The k factor is the ratio of the neutral axis location t to the material thickness mt.

The bend deduction of means that the material is expected to stretch by that amount during the course of bending. So if the thickness of the sheet was a distance of t 1 mm and the location of the neutral axis was a distance of t 0 5 mm measured from the inside bend then you would have a k factor of t t 0 5 1 0 5. When metal is bent the top section is going to undergo compression and the bottom section will be stretched.