[Healeys] sand in your luggage rack.............?

[BJ8 Healeys]

Ray, every object has a natural frequency of vibration.  If an external
force (the wind, car vibrations, etc.) excites the object at its natural
frequency, the vibration amplitudes are increased.  Changing the mass or
stiffness of the object will change the natural vibration frequency, so
adding sand to the luggage rack to change its mass and frequency response
makes sense to me.
 
Steve Byers
HBJ8L/36666           
BJ8 Registry
Havelock, NC  USA
 
 
 
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of raymead at comcast.net
Sent: Tuesday, December 28, 2010 12:41 PM
To: AUSTIN HEALEY CLUB
Subject: [Healeys] sand in your luggage rack.............?
 
hello all,



i was reading an article that talked about excessive wind noise after a
luggage rack was installed (not on an AH).

the solution to the problem was to fill the rack with sand, which stopped
the
tubes from resonating/vibrating,,,,,



i've never heard of this!B  is this something everyone else in the free
world
already knows about?



ray