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Problem with creating beam model

Problem with creating beam model

Problem with creating beam model

(OP)
Hello everybody!

I am currently working on creating a beam model which consists of several beams connected by nodes. They are constrained by a single 6-DOF-zero-displacement in the first node. Everytime I create the beams in a line (that means they all have the same direction) everything works fine. As soon as I create them having angles between them, the analysis stops with the famous "excessive pivot ratios" mistake. I just don't know what might fix the problem. Could anybody please help me?

Here is the bdf with a test version of two beams:

$ NASTRAN input file created by the Patran 2010 (MD Enabled) input file
$ translator on February  07, 2011 at 13:52:45.
$ Direct Text Input for Nastran System Cell Section
$ Direct Text Input for File Management Section
$ Direct Text Input for Executive Control
$ Linear Static Analysis, Database
SOL 101
CEND
$ Direct Text Input for Global Case Control Data
TITLE = MD Nastran job created on 07-Feb-11 at 13:46:18
ECHO = NONE
SUBCASE 1
$ Subcase name : lc1
   SUBTITLE=lc1
   SPC = 2
   LOAD = 2
   DISPLACEMENT(SORT1,REAL)=ALL
   SPCFORCES(SORT1,REAL)=ALL
   STRESS(SORT1,REAL,VONMISES,BILIN)=ALL
BEGIN BULK
$ Direct Text Input for Bulk Data
PARAM    POST    -1
PARAM   PRTMAXIM YES
$ Elements and Element Properties for region : beam1
PBARL    1       1               BAR
        1.      1.
$ Pset: "beam1" will be imported as: "pbarl.1"
CBAR     1       1       1       2       0.      0.     1.
CBAR     2       1       2       3       0.      0.     1.
$ Referenced Material Records
$ Material Record : a
$ Description of Material : Date: 07-Feb-11           Time: 13:50:56
MAT1     1      1.+9
$ Nodes of the Entire Model
GRID     1               0.      0.      0.
GRID     2              1.      1.       0.
GRID     3               0.     1.      1.
$ Loads for Load Case : lc1
SPCADD   2       1
LOAD     2      1.      1.       1
$ Displacement Constraints of Load Set : dof1
SPC1     1       123456  1
$ Nodal Forces of Load Set : f1
FORCE    1       3       0      10.      0.      0.     1.
$ Referenced Coordinate Frames
ENDDATA 762d9011


Regards
Martin

RE: Problem with creating beam model

(OP)
Hello again!

Problem is solved. Poisson ratio was missing. I didn't expect it to be necessary.

Thanks anyways!

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