METBD 350/450/451/452: BEAM/TRUSS Postprocessing

MET 415/425 Lecture Notes

Postprocessing BEAM & TRUSS (POST1) [Use of the Element Table]

Reference: ANSYS Basic Analysis Procedures Guide, Chapter 5.4.2

In ANSYS: Type "help,188" to see the element manual pages on BEAM188

Find TABLE 188.1 (which is the BEAM188, Element Output Definitions)

Examine "stress" quantities: SDIR, SByT, SByB, SBzT, SBzB
Examine "force" quantities: Fx, My, Mz, SFy, SFz

Find TABLE 188.2
which is BEAM188, Item and Sequence Numbers

Find the stress or force quantities you want to postprocess.

Examples:

Fx (at node I) Item: SMISC Seq. No. 1

MZ (at node I) Item: SMISC Seq. No. 3

MZ (at node J) Item: SMISC Seq. No. 16

SFy (at node I) Item: SMISC Seq. No. 6

SFy (at node J) Item: SMIS Seq. No. 19

In the General Postprocessor > Element Table > Define Table > ADD [Command: ETABLE]

Enter a user-defined name: (how about Fx-i for the 1^st one)
Pick "By Sequence Num", SMISC, add the seq. no. to the SMISC,

Then you can PLOT or LIST the Element Table Results [Commands: PLETAB or PRETAB]

In the General Postprocessor > Plot Results > Line Elem Res. [Command: PLLS]
You can contour the I and J results along the beam (V or M diagrams)

NOTE 1: BEAM188 & 189 don’t use element table often, you can contour vonMises or other stress results when /ESHAPE,1 is on.

NOTE 2: Many elements have "extra" data available in Element Tables.

Table 188.1 BEAM188 Element Output Definitions

SF: y,z	Section shear forces
Fx	Axial force
MY, MZ	Bending Moments

Table 188.2 BEAM188 Item and Sequence Numbers

Output Quantity Name	ETABLE and ESOL Command Input
Output Quantity Name	Item	I	J
Fx	SMISC	1	14
My	SMISC	2	15
Mz	SMISC	3	16
SFz	SMISC	5	18
SFy	SMISC	6	19

ANSYS Menu selections:
Postproc > Element Table > Define Table > Add
    Fx-i, By Sequence Number, SMISC,1
    Fx-j, By Sequence Number, SMISC,14
    SFy-i, By Sequence Number, SMISC,6
    SFy-j, By Sequence Number, SMISC,19
    Mz-i, By Sequence Number, SMISC,3
    Mz-j, By Sequence Number, SMISC,16

A WORKBENCH command object to access this data might look like:

allsel

ESEL,S,ENAME,,188 ! select only BEAM188 elements

ETABLE,Fx-i,SMISC, 1 ! axial force in BEAM188, node I
ETABLE,Fx-j,SMISC,14 ! axial force in BEAM188, node J

ETABLE,Mz-i,SMISC, 3 ! z-bending moment in BEAM188, node I
ETABLE,Mz-j,SMISC,16 ! z-bending moment in BEAM188, node J

ETABLE,SFy-i,SMISC, 6 ! y-shear force in BEAM188, node I
ETABLE,SFy-j,SMISC,19 ! y-shear force in BEAM188, node J

PLLS,Fx-i,Fx-j

PLLS,Mz-i,Mz-j

PLLS,SFy-i,SFy-j

allsel

Help,LINK180

Table 180.1 LINK180 Element Output Definitions (to find the definition of each output item)

Force	Member force in the element coordinate system
Sxx	Axial Stress

Table 180.2 LINK180 Item and Sequence Numbers

Output Quantity Name	ETABLE and ESOL Command Input
Output Quantity Name	Item	E	I	J
Force	SMISC	1	-	-
Sxx	LS	-	1	2

ANSYS Menu selections:
Postproc > Element Table > Define Table > Add
    Force, By Sequence Number, SMISC,1
    Sxx-i, By Sequence Number, LS,1
    Sxx-j, By Sequence Number, LS,2

A WORKBENCH command object to access this data might look like:

allsel

ESEL,S,ENAME,,180 ! select only LINK180 elements

ETABLE,Force,SMISC, 1 ! axial force in LINK180 elements

ETABLE,Sxx-i,LS,1 ! axial stress in LINK180, node I
ETABLE,Sxx-j,LS,2 ! axial stress in LINK180, node J

PLETAB,Force

PLLS,Sxx-i,Sxx-j

allsel