Design of nonlinear spring from load deflection graph

[jinnkraft]

Hi

Could anybody guide me to a software that can be used to design a non linear spring from load deflection characteristics. need it for both extension and compression spring.

thanks
noor

 

[billy_joule]

Excel? ANSYS? Solidworks simulation?
Variable rate springs are an OTS (off the shelf) item, or u can stack two (or more) springs in series. Or a redesign could remove the need for a progressive rate spring altogether. Could you be more specific? A diagram perhaps? Generally, you'd avoid needing custom designs of basic components (nuts, bolts, springs, washers etc)

 

[jinnkraft]

Thanks for your reply
I need to design a nonlinear extension spring. I've readied a graph based on my design criteria.

Based on this graph, i want to design the extension spring.
please provide more insight on design methodology
Moreover i must use a single spring of small weight and dimension.

thanks
noor

 

[billy_joule]

Your graph looks like it could be well approximated with just two spring rates, so a dual pitch spring, or maybe a Belleville spring stack.
Most/all mechanical engineering design books will have a chapter on springs, I'd recommend Shigleys Mechanical Engineering Design (it has many references to more detailed resources)
Off course, google has many resources too, including manufacturers with spring design software that can do the design for you...