Solid Modeling of new springs ...

[Doppe]

Does anyone out there use SolidWorks 2005 and an FEA package to model and analyse new coil spring designs? Which FEA package are you using and how successful has this method been?

I'm wanting to design double start rectangular section variable pitch coil springs but not sure which is the best way to do this.

 

[israelkk]

Double start spring is basically two springs in parallel. Doing a solid model is easy using Solidworks or Alibre Design and probably any other 3D parametric CAD system.

Any FEA program with large deflection non-linear capabilities can do the job. But the issue is not to analyse a given spring but to find a spring that will give you the spring that will do the job.

So, you will have to check for many many spring designs until you receive a satisfactory result. A large deflection non-linear analysis is a very time consuming process for the computer therefore, you may end up with a very long process and as a result quite expensive.

When dealing with variable pitch springs the issue is even more complicated. You probably want at least two load points with a specified deflection between the two points. This is not a simple task. There is no direct solution for such a problem. You have to try a variety of spring designs and look for the spring load-deflection curve that passes between those two points. It is a complicated process even with a dedicated computer program that uses analytical proven formulations for spring design.

It is almost impossible or alternatively very time consuming and very expensive process using FEA analysis.

Remember, that the spring has to be designed not to be over stressed and probably for a specified fatigue life cycle added to the previously mentioned issues.