Effects of Parallelism and Squareness on Load over Time

[mcardle27]

Hi, my question is regarding compression springs. I was curious as to what the effects of parallelism and squareness have on the ability of a compression spring to hold a specific load over time>

From my understanding, I know that as these conditions increase the force from the load will not act through the center line of the spring. I am guessing this means the load distribution on the contacting surface of the spring would not be even? This would also mean that the stress through the coils will not be evenly distributed either?

Would this affect the springs overall ability to hold a specific load over time though? Especially if the parallelism and squareness are specified to 2-3 degrees?

I apologize if this is a noob question, but I have been pouring through my text books and I might just be missing something.

 

[MikeHalloran]

For a helical compression spring, the force almost never acts through the center of the spring, so the whole load/time question's answer has to involve whatever mechanism reacts the loads and guides the spring ends, in addition to any factors that are internal to the spring itself.

Note that the wire in the intermediate coils is stressed in torsion; i.e., a helical coil spring is really a torsion bar wrapped into a helix. The last coil or so act as the levers that connect the torsion bar to the external world. The stress situation in those end coils is complex enough to make my head hurt.







Mike Halloran
Pembroke Pines, FL, USA