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neutral bend factor

neutral bend factor

neutral bend factor

(OP)
is it possible to change the material type and have it linked to change to the relevant neutral bend factor (obviously would be done before creating any flanges)??

RE: neutral bend factor

Yes, but you have to assign the Material INSIDE of NX Sheet Metal.  Changing the Material via the...

Tools -> Material Properties...

...function will NOT control the 'physical' characteristics of Sheet Metal.  However, if after you enter the NX Sheet Metal application, go to...

Preferences -> NX Sheet Metal -> Part Properties

...and under Parameter Entry, select 'Material Selection'.  When you do, the 'Select Material' button becomes active.  Select it and from the dialog that comes up you can either select an explicit set of Material Characteristics or you can select from one of the list of pre-defined SAMPLE materials (the key word here is 'sample' as these are not really usable as is, but more on that later).  Once you've either manually configured a new Material Characteristic or selected one of the pre-defined ones, when you hit OK and return to the main Preferences dialog you will see that all of the settings have been changed and are grayed-out since they are now being controlled by the changes made in the Material Characteristics dialog.

Now as to where the data is coming from for the pre-defined SAMPLE materials, you'll find a file named 'sheet_metal_material_table.txt' in the...

<NXVersion>\UGII\materials

...folder.  Now this file is provided only as a 'sample' as it was never intended to represent an actual list of materials.  That's up to our customers to provide the content.  If you open this file there is information in the header as to how the file is formatted and what information is needed to be included.  If your desire is to define a set of standard materials, here is where you would assign the various parameters and set the various material characteristics as well as other NX Sheet Metal standard parameters.

Note that this material file is shared between both NX Sheet Metal and Aerospace Sheet Metal, but NOT the older SMD (Sheet Metal Design) nor the 'Forming/Flattening' modules.

Now this brings us to a few issues which you need to be aware of.  Like there is another Sheet Metal material data base supported by NX but that was for the old SMD modules, so don't worry about.  Also, don't try to set any Preferences unless you're actually in the NX Sheet Metal module (it you're not in the NX Sheet Metal module, if you go to preferences you'll find a Sheet Metal area, but that was for OLD SMD modules so leave it alone).

And the last thing is that if you do change Sheet Metal materials, that has NO effect on the 'Material Properties' of the part model itself, only the way that the NX Sheet Metal functions work.  If you wish to also have an accurate mass density as well as CAE properties, you will still need to assign a traditional material using the...

Tools -> Material Properties...

...function.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: neutral bend factor

(OP)
Thanks John for your detailed reply, i tried it and it works great, so the first part (tools material proporties) only relates to if you were to require the density and weight to be calculated?
Do you know where i can find some values for the bend factor, I only need it for basic materials such as
Aluminium 5005, 6061, Stainless steel 304, mild steel

RE: neutral bend factor

You will probably have to start with the supplier of your sheet stock as there are a number of items which effects the K-Factor, including not only the material thickness, but the yield-point and other physical properties of the metal.  Also for very high precision work even the inside radius of the bend can have an effect particularly if it's very small.  Also the type of bending process or tooling used can have an effect as the results can vary depending on the style of die used as there are several different types for different situations or desired results.

Generally speaking, the K-factor can be anywhere from 0.30 to 0.50.  For mild steel, it's generally 0.33 to 0.40.

However I did find a reference which while it does not provide a table based on particular materials, it does do a good job of describing the various factors involved, and of particular interest, it does attempt to show how the various styles of dies and processes can effect the K-Factor for at least some broad classes of materials.

This information can be found at:

http://www.ciri.org.nz/bendworks/bending.pdf

Anyway, I hope this helps.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: neutral bend factor

(OP)
ok thanks for your help

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