no details so just educated guess
could we be looking at pseudo-time? In other words it's not time but load (factor) and 1.0 being the full load (applied to the FEM). Some sort of non-linear analysis (no idea what kind of non linearity if any)
I think there is a relation between translation (T) and rotation (R) (assumed very small)
{Tind} = {Tdep}+{R}{v} where v must be the vector defined by the position of the dependant and each independent node
If you consider an RBE3 with 3 dependant nodes working purely in 1 direction then If I...
To all,
Does anyone know a good source/ref for the equations used by (nastran) RBE2 element to get the load distribution assuming a force being applied at the independent node? I remember seeing something in the old msc.nastran manual but cannot find it anymore
If one was to set-up a simple...
what the frequency of these RBE elements on each end? Close to zero?
There is an example of a beam attached at 1 one and an exciting force at the other end
you don't say which version of Nastran you are suing. Anyone reading the QRG will find something along these lines
The number of suspected massless mechanisms is determined from the number of high ratio messages. If this number exceeds NLMAX, the number of trial massless mechanisms is reduced...
I do not recall a link between the Jacobian and integration points. The Jacobian is just a scalar value (a determinant of a 2x2 matrix containing the 1st derivative of the shape function if I recall). As stated by E720 it links the perfect/theoretical shape (say a square) to the actual shape of...
in Patran one used to be able to create an interpolated 3D field - did that a long tine ago!
[ol 1]
one had to import the CFD mesh making sure that the CFD and structural mesh are as close as possible,
create the pressure distribution and apply it to the CFD mehs (one-to-one relation)
With...
by de-activating I meant not including it in the random response. When you use a modal technic for a random analysis one can select which mode to include. If one calculates N modes then "by default" all N modes are included. With some software (all of them!) one can request for some modes not to...
Thanks for the replies & suggestion. I have not checked with a 2dof system. I did the test as I wanted to report the effect (on the rms response) of the mode de-activated. With all the modes selected I get X, with all but 1 mode I get Y. Y/X shows that the mode de-activated represents p% of X...
To all,
A question about the modal approach of solving response for a random analysis
With my test FE Model I de-selected 1 mode and compared the PSD response (acceleration) to a prediction will all the modes. The mode selected has a mass participation of 2%
The PSD response with the mode...