2 RBODY Master on the same node

Altair Forum User

I'm building RADIOSS model of a square plate under impulse loading to calculate the reaction force.

 

The boundary condition is follows,

  -<A> full constraint on the 4 edges (RED in picture)

     and

  -<B> only translation in out-of- plane direction is constrained on some area of the plate(Blue in picture)

 

In order to create this B.C.s, I used 2 RBODYs  which share the same master node.

The master node is fully constrained by SPC and output of REACX on that node is defined to output reaction force.

 

Running RADIOSS returns ERROR 442,

 

** ERROR IN RIGID BODY DEFINITION
DESCRIPTION :  
   -- RIGID BODY ID : 47869
   -- RIGID BODY TITLE :
   AT LEAST TWO RIGID BODIES USE THE SAME MASTER NODE ID=87278

 

I know switching either of RDOBYs to SPC will fix this problem but I can't get correct reaction force.

 

Is there any way to go through this problem?

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hi Yoshida,

This is an  incompatible condition. You are defining two boundary conditions in the same master node, and the same will be affected to all the slave nodes connected to the master node. You have to specify separate master nodes for the rigid bodies and has to request for REACX in the time history.

Also you can request animation files for reaction forces for imposed velocities, displacements, accelerations and boundary conditions using /ANIM/VECT/FREAC card in the engine file.