John;
The problem is fatigue failure caused by the vibration of a moving
trailer. A long wheelbase dragster chassis has a lot of flex (a beam in
bending supported at each end) so over time the points having the
greatest stress * cycles causes fatigue cracks to appear.
Frankly, I'd be very leery of a chassis design that was that fragile.
Not to say I wouldn't support it to minimize the flexing but I'd
definitely look at the design with an eye toward making it as fatigue-
resistant as possible (think light aircraft design) and I'd inspect it
carefully after every meet.
Drag racing is an intense but very short event so fatigue failures take
some time to show up unless they are put on a "shake table"-- aka a
towed trailer.
Regards, Neil Tucson, AZ
-----Original Message-----
From: owner-land-speed@autox.team.net
[mailto:owner-land-speed@autox.team.net] On Behalf Of Dave Dahlgren
Sent: Thursday, September 29, 2005 12:48 PM
To: John Burk; land-speed
Subject: RE: Chassis Cushion?
That might be true if the trailer never moved. Having the car blocked
solid
going over the road is more like a 24 hour earthquake. Most roads have
bumps
and potholes that impart significant g forces vertically while the
trailer
is moving. My garage floor is a bit more stable.. I am certain your
logic is
tragically flawed.
dave
> -----Original Message-----
> From: owner-land-speed@autox.team.net
> [mailto:owner-land-speed@autox.team.net]On Behalf Of John Burk
> Sent: Thursday, September 29, 2005 3:20 PM
> To: land-speed
> Subject: Re: Chassis Cushion?
>
>
> With the chassis lightly resting on wooden blocks towing puts no
more
> vertical stress on things than if the car was in the garage .
|