Torsion Spring Life Cycle
Torsion Spring Life Cycle
(OP)
Hi,
I am currently reverse engineering a program to build my own worksheet to calculate the cycle life and spring length required (or number of coils) for a garage door. The torque, number of winds, and inside diameter are calculated separately. The wire diameter chosen will be based on a life cycle of at least 25k and spring length of at least 8".
I was able to calculate the number of coils using:
k = (E*d^4)/(10.8*D*N)
T = k*(number of winds)
Bending Stress from torsion calculated using:
S = (Kb)(32*T)/(pi*d^3)
Now I am having trouble finding a formula to calculate the cycle life based on the stress. The program I am currently using has to be using one, but i can't seem to figure it out. Can anyone point me in the right direction?
Thanks.
I am currently reverse engineering a program to build my own worksheet to calculate the cycle life and spring length required (or number of coils) for a garage door. The torque, number of winds, and inside diameter are calculated separately. The wire diameter chosen will be based on a life cycle of at least 25k and spring length of at least 8".
I was able to calculate the number of coils using:
k = (E*d^4)/(10.8*D*N)
T = k*(number of winds)
Bending Stress from torsion calculated using:
S = (Kb)(32*T)/(pi*d^3)
Now I am having trouble finding a formula to calculate the cycle life based on the stress. The program I am currently using has to be using one, but i can't seem to figure it out. Can anyone point me in the right direction?
Thanks.





RE: Torsion Spring Life Cycle
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Torsion Spring Life Cycle
You should better move the post to the "Spring engineering Forum" (forum693: Spring engineering - Professional forum and technical support for engineers for Spring engineering. Includes problem solving collaboration tools.)
https://sites.google.com/site/israelkk/
RE: Torsion Spring Life Cycle
And yes, each table is for a specific material (music, OTMB, Rocket, ....) and there are size corrections.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Torsion Spring Life Cycle
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?