Grouping loads and constraints prior to export (Simcenter Samcef)

Simcenter 3D groups loads and constraints (when possible) before their output in the Simcenter Samcef input file.

The automatic grouping process depends on:

• The content of the supports.

• The expression of degree-of-freedom dependencies that need to be written on multiple lines or not.

• The expression of option dependencies that need to be written on multiple lines or not.

The following examples illustrate the grouping rules.

One support and one DOF per line

Example of the User Defined Constraint constraint.

Before grouping (node based output):

.CLM ADD  NOEUD I 38 DEP C 1 V 45 NOEUD I 39 DEP C 1 V 45 NOEUD I 40 DEP C 1 V 45

After grouping:

! Samcef Bank File : GROUPS.! --------------------------.SEL GROUP 1 NOEUDS NOM "UserDefined(1)" I 38 J 40 K 1 .CLM ADD GROUP "UserDefined(1)" DEP C 1 V 45

where UserDefined(1) is a Simcenter Samcef group containing the nodes 38, 39, and 40.

One support but one DOF per line

Example of the Contact with Clearance constraint.

Before grouping (node based output):

.JEU I 14 C 1 FIX 1 N 1 I 14 C 2 FIX 2 N 1 I 14 C 3 FIX 3 N 1 I 15 C 1 FIX 1 N 1 I 15 C 2 FIX 2 N 1 I 15 C 3 FIX 3 N 1

We have two nodes that undergo the same fixation.

After grouping:

! Samcef Bank File : GROUPS.! --------------------------.SEL GROUP 11 NOEUDS NOM "GroupNode1" I 14 J 15 K 1 .JEU! ! Contact with Clearance(2) GROUP "GroupNode1" C 1 FIX 1 N 1  GROUP "GroupNode1" C 2 FIX 2 N 1  GROUP "GroupNode1" C 3 FIX 3 N 1

where GroupNode1 is a Simcenter Samcef group containing the nodes 14 and 15.

One support and one line per option

Example of the thermal Cavity Convection simulation object: .CLT EXP CNN CAV CONV.

Before grouping (face based output):

.CLT FACE I 43 4 CAV V 1 FACE I 43 4 CONV V 1e+06 FACE I 43 4 CNN V 36 FACE I 43 4 EXP V 2 FACE I 45 3 CAV V 1 FACE I 45 3 CONV V 1e+06 FACE I 45 3 CNN V 36 FACE I 45 3 EXP V 2

After grouping:

! Samcef Bank File : GROUPS.! --------------------------.SEL GROUP 11 FACES NOM "GroupFace" FACE I 43 4 FACE I 45 3 .CLT GROUP “GroupFace” 4 CAV V 1  GROUP “GroupFace” 4  CONV V 1e+06 GROUP “GroupFace” 4 CNN V 36 GROUP “GroupFace” 4 EXP V 2

where GroupFace is a Simcenter Samcef group containing the faces 43 and 45.

Counterexample 1: a nodal force defined with a spatial field

When you define a nodal force with a spatial field, the magnitude of the load varies on each node. The output will be:

.CLM ADD! direction  X=0 Y=0 Z=-1; Total Value=250 NOEUD 5 CHA  C 3 V -250! direction  X=0 Y=0 Z=-1; Total Value=125 NOEUD 10 CHA  C 3 V -125! direction  X=0 Y=0 Z=-1; Total Value=125 NOEUD 13 CHA  C 3 V -125! direction  X=0 Y=0 Z=-1; Total Value=125 NOEUD 15 CHA  C 3 V -125! direction  X=0 Y=0 Z=-1; Total Value=125 NOEUD 18 CHA  C 3 V -125...

No grouping action is performed, even for the few nodes that undergo the same load.

Counterexample 2: a constant nodal force applied on the geometry

When you apply a constant force on a geometry, Simcenter 3D will compute the finite element equivalent values at the nodes of the mesh:

.CLM ADD NOEUD 86 CHA  C 1 V 1000 NOEUD 86 CHA  C 2 V 1000 NOEUD 86 CHA  C 3 V 1000 NOEUD 91 CHA  C 1 V 1000 NOEUD 91 CHA  C 2 V 1000 NOEUD 91 CHA  C 3 V 1000 NOEUD 94 CHA  C 2 V 1000 NOEUD 94 CHA  C 3 V 1000...

Again no grouping action will be done.

List of Simcenter Samcef loads and constraints that can be automatically grouped

Structural boundary conditions
.CLM	CHA, PRESS, ACC.ROT, DROT.FIX, DEP.VFX, DEI, VII.
.CLT	TFX, PH1, PH2.
.JEU
.BOLT

Thermal boundary conditions
.CLT	LOAD, FLUX, FLV.EMI, TFR, TT0.TFX, TIN.EXP, TFC, CONV, CNN, CAV.

Look up more details

Advanced Solver Options dialog box (Simcenter Samcef)

Quick links

Command reference

Pre/Post video examples

Bulk Entry Descriptions

Simcenter 3D tutorials

Browse Simcenter 3D help by product area

Grouping loads and constraints prior to export (Simcenter Samcef), Simcenter 3D 2021.1 Series

© 2020 Siemens

window.mainLanguage="en_US"

window.delivId=""

window.projectId=""

MathJax.Hub.Config({ TeX: { extensions: ["autoload-all.js"] }, tex2jax: { displayMath: [ ] }, "SVG": { scale: 125 } });