[ddubahshi (OP)]

Why is there a Unwanted Noise generated whenever a Load or Force is applied on a Compression or Tensile Spring?

What causes this Noise and How can this be eliminated?

[barbarara]

Maybe, gravity and friction force?) Try listening to music))

[Colin2B]

Usually due to parts of the spring rubbing together. Try oil or grease.

[Bill S]

Could molecular friction be involved?  What level of noise are we considering?

[Colin2B]

What level of noise are we considering?

Think bed springs. I’m sure you’ve made them squeak a few times 
I would expect crystal or molecular friction to be much quieter unless you are getting close to fracture.

I think we are talking about parts of spring rubbing either on other parts of the spring or the attachment points.

[ddubahshi (OP)]

At present Noise Level is not verified, but we may define this type of Noise as Squeaky. There is no adjacent Parts for Friction.

In NVH there are different type of Noise like Squeak, Rattling, Tick Noise, Click Noise..

[Colin2B]

There is no adjacent Parts for Friction..

So how are you compressing or extending it?
Photo?

[ddubahshi (OP)]

Load is applied in line with the axis of Spring. One side of the Spring is fixed and the other side is loaded by means of Cylinder.

Capture.JPG (27.69 kB . 318x441 - viewed 2007 times)

[Colin2B]

Cant see your attachment.
If one side of spring is fixed and other in contact with cylinder then you have 2 possible areS of friction and squeaking.

Ok, can see it now. You clearly have substantial contact between the upper and lower plates and the spring, I would start there.
What is the green colour? Paint or a plastic coating?

[ddubahshi (OP)]

The given Image is a replica and not in actual. However the real application is same or similar in loading points and application of load. The actual application Part has a Trivalent Electro-Plating.

The Noise generated is not due to contact of the Load application points. For instance consider that the Points are always in contact. The Noise is like crunching/ sqeeking when the Spring is been loaded to achieve its solid length.

Application of Oil/ Grease sometime does reduce the Noise but it does not seem to be correct. How application of lubricant on the outside surface reduce the Noise generated from within the Part.

[Colin2B]

The Noise generated is not due to contact of the Load application points. For instance consider that the Points are always in contact. The Noise is like crunching/ sqeeking when the Spring is been loaded to achieve its solid length.

The ends are always in contact, but the contact area does move. Consider that when compressed your spring will increase in diameter, hence the ends will move/twist relative to the pressure plates.

Application of Oil/ Grease sometime does reduce the Noise but it does not seem to be correct. How application of lubricant on the outside surface reduce the Noise generated from within the Part.

Where did you apply the grease? Between the ends of the springs and the pressure plates?

[yor_on]

Can't you consider the spring as a string under tension, aka a guitar string? Then, if you apply a force on the guitar string it vibrates.