Is it possible to get the acceleration used for an inertia relief (statics)?

[engineerbe]

When performing a static analysis with use of inertia relief, one will get translations and stresses as results. Is it also possible to read out the acceleration that was used during the analysis?

 

[rb1957]

?

doesn't "inertia relief" refer to weight ? (like the weight of fuel in the wing)

if you're applying a body force, don't you have to tell the FEA the acceleration ? (i don't think it'll solve for this ... i think you have to apply it)

 

[engineerbe]

We've performed a simple test: A cube meshed with 125 Hex elements, no constraints, only a surface force applied. The option Inertia Relief (automatic), INREL,-2, has been set. The results show a logical deformation, the cube is compressed by the force in one direction. NX Nastran adds an acceleration matrix to the equation in order to get an equilibrium, at least that's what I make up from the helpfiles. The value for the acceleration is not listed anywhere?

 

[rb1957]

that's an astounding test ... given the smarts to get the result i'd go with a = F/m but i appreciate your anting to see the number it calc'd.

maybe apply a body force to react your surface force (and you should get the same results).

i'd also check your AUTOSPC, i suspect it's on

 

[Jetgirl8]

You can find it in the output file (sample below).

R I G I D B O D Y A C C E L E R A T I O N V E C T O R

SUBCASE T1 T2 T3 R1 R2 R3
ID
1 0.000000E+00 0.000000E+00 -1.363977E+05 -1.716199E-11 1.364990E-12 0.000000E+00

Searching the forum for inrel or inertia relief also should help you out with some useful advice.