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RE: Stack Strakes

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In our lab tests of an aluminum lighting pole mounted on a rigid frame with 
 nothing attached to the pole but a rigid mass at the top, we got a damping 
 ratio of 0.0018.  This same pole with one of our impact dampers gave us a 
damping ratio of 0.0088.  Some dampening would be provided by the 
electrical wiring, bolted joints, light fixtures and the soil around the 
foundation of lighting pole in the field, so the laboratory damping ratios 
are probably considerable lower than for an installed pole.


-----Original Message-----
From: seaint-seaosc(--nospam--at) [mailto:seaint-seaosc(--nospam--at)] On 
Behalf Of h.d.richardson(--nospam--at) Sent: Monday, February 04, 2013 4:58 PM
To: seaint-seaosc(--nospam--at)
Subject: Re: [SEAINT-SEAOSC] Stack Strakes


        Thank you, Ray.  I will definitely look into  that if I proceed 
with the concept of wire rope strakes.  I see other benefits as well: I 
wouldn't have to check wire rope stiffness in bending to avoid the impacts; 
 I wouldn't have to use clips that clamp the wire, just restrain it from 
moving out of position; the clips could be much farther apart, hence, many 
less of them; and maybe more.

        If you use impact dampers frequently what sort of damping ratio 
would you guess would be reasonable?


H. Daryl Richardson

----- Original Message ----- From: "Ray Minor" <ray.minor(--nospam--at)>
To: <seaint-seaosc(--nospam--at)>
Sent: Monday, February 04, 2013 2:12 PM
Subject: RE: [SEAINT-SEAOSC] Stack Strakes

Truncated 1021 characters in the previous message to save energy.

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