topic Re: Straight Length For Bent Bar in AutoCAD Forum

Straight Length For Bent Bar

Anonymous — Thu, 02 Mar 2017 10:51:03 GMT

How do we find out the total length for a bend part in Auto Cad.

I need a solution apart from adding the sum of all the lengths individually i,e make the bend part appear straight in autocad.

Re: Straight Length For Bent Bar

Alfred.NESWADBA — Thu, 02 Mar 2017 10:56:59 GMT

Hi,

please show a drawing so we can see how you have created bend parts and which types if geometry objects that are.

In principle: Vanilla AutoCAD don't support bending (without having some apps installed which can do that).

- alfred -

Re: Straight Length For Bent Bar

Anonymous — Thu, 02 Mar 2017 11:08:34 GMT

The diameter is 8.00 mm

Re: Straight Length For Bent Bar

Alfred.NESWADBA — Thu, 02 Mar 2017 11:38:05 GMT

Hi,

as already mentioned, AutoCAD does not have a tool that can do these calculations of bending (stretching and compression), so you need to use additional applications or calculate it manually.

Sorry, - alfred -

Re: Straight Length For Bent Bar

leeminardi — Thu, 02 Mar 2017 14:11:08 GMT

If you create a single polyline down the center of the bar you can use the LIST command to give you the total length of the polyline. To get the total unbent length you would need to factor in the bend allowance for each bend using equations such as those here:

https://www.scribd.com/doc/158186639/Bend-Allowance-Calculator

Lee

Re: Straight Length For Bent Bar

Washingtonn — Thu, 02 Mar 2017 14:24:36 GMT

@Anonymous wrote:
How do we find out the total length for a bend part in Auto Cad.

I need a solution apart from adding the sum of all the lengths individually i,e make the bend part appear straight in autocad.

OK, you have started a new post for the same issue for your previous post (How to draw this drawing in autocad 02-23-2017 05:31 AM)

- this post has the diameter that was never provided for the previous post which is good. I am a little perplexed that you were not able to find any information as suggested for a solution in the other post (assuming you did a search). In any event, based on the responses for this post, you now know that you need something beyond basic AutoCAD to find your answer.

Take a look at this link < https://en.wikipedia.org/wiki/Bending_(metalworking) > - it is one of the MANY links listed from a search for "Bending Allowance". At many of these sites, you will find information, graphics and equations which will help resolve your issue

Re: Straight Length For Bent Bar

Anonymous — Thu, 02 Mar 2017 16:22:29 GMT

See the picture below:

Just join all of the line segments that make up the outermost line of the rebar, the offset that the radius of the bar and then LIST the new polyline in the center of your bar to have AutoCAD tell you the length of it. This is a really easy thing to do.

Re: Straight Length For Bent Bar

Washingtonn — Thu, 02 Mar 2017 17:34:10 GMT

You are assuming that the neutral axis is located at the center of the rod which is seldom the case when it comes to bending thus the starting length before bending will be different but the difference may not be significant to the OP given the tolerances indicated.

The neutral axis is dependent on such things as the material involved , how the material is bent, and the bend angle.

The K-factor is the ratio of the distance of the neutral axis (from the interior bend side) to the material thickness and is typically 0.25 < K-factor < 0.50