Snow Ice Strength

[strainstress]

I am trying to figure out torque required to actuate a damper against ice-built up of 6 in on the blades.

Does anyone know where to find snow ice mechanical strength properties (tensile and shear strength) ?

Thanks,

StressStrain

 

[EnergyProfessional]

wouldn't you bend the blades? how the ice sits int he blades will be different every day, so hard to calculate... but at the end of the day you ruin everything trying to force it. If ice is a concern, did you think of a screen to protect the damper?
or is ice formed form indoor humid air creeping to the damper?

 

[MintJulep]

Start here and follow references until you find what you're looking for.

http://www.crrel.usace.army.mil/library/technicalnotes/TN03-4.pdf

 

[chicopee]

Is it possible to get an image of the damper with dimensions of the vanes, spacing between vanes, position and measurements of the linkage, spring constant of the spring aiding in closure or opening of the vanes? We know the weight of ice so figuring out the amount of force and torque may not be a significant problem. What would be disastrous to the damper and motro is trying to break up the ice buildup blocking the vanes.

 

[strainstress]

The damper is similar to

http://www.ruskin.com/model/CD35

We are concerned about damper operating to break the ice blocking the vanes. Using heat tapes is not an option because this damper has to operate in case of a power failure.

Knowing that ice strength varies widely based on the kind of ice built-up, I am looking for strength of rime ice.

 

[chicopee]

Instead of the damper operating vertically as shown in your link, you could extend an elbow from the wall opening and have the duct operate horizontally facing downward.

 

[strainstress]

That is a good suggestion chicopee, let me run it past the project engineer to see if we are allowed to it on this project. Thanks .