Spring stiffness of a helical spring
Submitted by Biswajit Banerjee on Tue, 2012-01-31 06:19.
Once in a while I have to find the stiffness of a spring that I get from the local hardware shop. I usually use a formula that can be found in some books on mechanics of materials.
But the assumptions bother me a bit because the springs that I used usually underwent large deformations and I wasn't sure whether the numbers I was using were correct or not.
To check the formula I compared its predicted k to numbers from Abaqus simulations and found reasonably good results for many situations - but not for soft springs.
I've attached a write-up on that that contains a python script to generate the geometry. Let me know if you find it useful.
| Attachment | Size |
|---|---|
| HelicalSpring.pdf | 136.54 KB |
| spring.py_.txt | 10.76 KB |
| springDataPlot.m.txt | 1.73 KB |
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helical spring
Hello Biswajit,
thank you for your posting. Please note the thread
http://imechanica.org/node/9188
and my reply in it. A while ago I downloaded a "helical wire plugin" from an ABAQUS web server, but the zip file was empty. Maybe your file will do the same job.
Frank
------------------------------------------ Ruhr-University Bochum Germany
Re: helical spring
Thank you for the link Frank. I've attached the python script to this post for convenience.
-- Biswajit
wire rope
Biswajit,
Would wire ropes be a good idealization of soft helical springs? Both you and I know of one application from our u/g days where that stuff is really useful!
In any case, if you think that is relevant, you may want to look up the work of G. A . Costello.
- Amit
Re: wire rope
Thanks for the pointer to Costello, Amit.
Computing the deformation of wire ropes, particularly in compression, can get quite messy. My question would be the opposite of yours, i.e., can we go from helical spring -> wire rope additively ? Costello says no in most situations.
Soft helical springs bend quite easily but are elastic and stable even for large deformations. That makes them suitable for many applications. Wire ropes probably have many advantages over single strand springs over a large range of length scales, as exemplified by hair/wool. But few natural structures have the coiled shape of a typical hardware-store spring. I wonder why.
-- Biswajit
I was asked question in my
I was asked question in my class that "Is there an easy way of find the spring sti ness of a helical spring without having to use an accurate load and displacement measuring system?" Actually I have to write thesis on said question. Yesterday I was thinking to avail online custom thesis writing service for the help. But After reading your lecture I think I can do it by myself.
Your topic and research is
Your topic and research is absolutely great. Now days my brother is studying about ibs treatment , he is medical student but I choose engineering as I think it is more intereting.