Helical plate bending

Hi everyone, I have a question for you :

I want to bend an helical plate so that I have a pitch of 8 inches. One end of the plate is going to be fixed and we will bend the other end. How can I know the amount of pressure needed to bend the plate for my need ? Is there a formula for this ?

[IMG]http://www.engineersedge.com/engineering-forum/attachment.php?attachmentid=1694&stc=1[/IMG]
This is a picture of the helical plate I want to make.
Anybody can help me ?

Martin Truchon

P.S: Sorry for my english, I'm french

For some help you might do a web search for "flat helical spring design" to find formulas for the the force and stress vs. deflection of that type of spring and then determine the force required to achieve/exceed the tensile stress of your plate material.

Already did my research on the internet but I found nothing ....

I did some looking and was surprised how little I could find (at one time I had a very good reference for this but I no longer have that document) what I did find is the below military document which (while of poor print quality) describes how to design edge wound flat coil springs which is representative of your problem. Goggle the complete below web search address from the front including the three dots ...


[TABLE]
[TR]
[TD="class: gsa_s"]... 10 Variation of final stress for springs coiled on flat and initial load P1 required
versus precompression ... D - mean coil diameter N - number of coils ...

and click on the first selection titled [B][URL="http://www.dtic.mil/dtic/tr/fulltext/u2/a077113.pdf"]Design of Helical Compression Springs[/URL][/B][/TD]
[/TR]
[/TABLE]

PS I know this is a strange web search address to enter but, trust me, it will work

[QUOTE=Martin T;12553]Hi everyone, I have a question for you :

I want to bend an helical plate so that I have a pitch of 8 inches. One end of the plate is going to be fixed and we will bend the other end. How can I know the amount of pressure needed to bend the plate for my need ? Is there a formula for this ?

[IMG]http://www.engineersedge.com/engineering-forum/attachment.php?attachmentid=1694&stc=1[/IMG]
This is a picture of the helical plate I want to make.
Anybody can help me ?

Martin Truchon

P.S: Sorry for my english, I'm french[/QUOTE]

Your searches might be more successful looking for how to make auger flights. There is a lot to look at but I didn't see anything about pressures. However you might get some ideas for another method.

Here's a video of a machine manufacturing a spring washer.. Following the forming operation heat treating to the desired condition is done.

[U][URL="http://www.engineersedge.com/video/Spring-Washer-Machine-M16-size_v1672"][COLOR=#333333][FONT=arial][B]Spring Washer Machine [/B][/FONT][/COLOR][/URL][/U]