XANSYS Message: 3214 [Go back to message list]
[bookmark on del.icio.us]
No rating yet
Subject: Re: Self Weight! -Reply
Author: Christopher Wright
Date: 1969-12-31 23:59:00>One item that sometimes causes confusion when applying gravity in
>ANSYS is that the inertia load is an acceleration vector and must act "up"
>in the positive Y direction.
I've found it less confusing thinking of gravity the way Newton did--an
attractive body force acting toward the center of the earth. What we
think of as gravitational acceleration is the acceleration of a body in
free fall. A body at rest on the earth's surface experiences a small
centripetal acceleration resulting from the curved path described as the
earth rotates.
What's really confusing is the fact that COSMOS and ANSYS use different
sign conventions for the gravitational acceleration. Another seriously
good reason to run a model under gravity loading alone--just to make sure
I'm not using the COSMOS sign convention with ANSYS input...
Christopher Wright P.E. |"They couldn't hit an elephant from
chrisw@s... | this distance" (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)
http://www.skypoint.com/~chrisw