compression spring design proof 1

[rmetzger]

We are currently working on establishing proof for the design of a number of compression springs. We've done the lab testing to get output results but management is also looking for analytical data to support the findings (does the engineering match the product kinda stuff). Ergo - I'm looking for a good compression spring calculator to help proof this (and save me from many hand calcs). Knowns are wire dia and matl, all dimensions, and a load at working height.

thanks

 

[CoryPad]

http://www.smihq.org/public/software.html

http://www.hexagon.de/fed_e.htm

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[israelkk]

Added to the calculations of the force at the deflection you need to check the stresses. More than that you have to carefully check for fatigue if the spring is loaded and unloaded periodically, you have to check for relaxation if the spring is under constant load for long period of time. Check for spring force manufacturing tolerances which are ususlly within +/-10% so the lab testing results may not be sufficient.

http://www.webspawner.com/users/israelkk/

 

[rcontractor]

This calculator worked well for me.

http://www.engineersedge.com/spring_menu.shtml

 

[Allen]

I myself most of the times use softwares along with my hand calculations to esnsure that the results are 100% true.

This is a good prog :

http://www.masterspring.it/

Also you can do a FEM analysis if you have the spring dims and material.

 

[drawoh]

rmetzger,

My machine design textbook from collge has a whole section on spring design. This ought to be a feature of all machine design books, right?

Design of Machine Elements -- Fourth Edition
Virgil M. Faires
MacMillan

Second hand copies of this are available all over the place.

There is a Spring Design Manual published by SAE. The Belleville spring equations are not quite identical to the ones in Roark's 5th Edition. I have not looked at their helical spring calculations.

If you set all this stuff up in a spreadsheet, you can punch in the charactersistics of springs from catalogues like Associated Spring SPEC. The numbers should work.

JHG