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MAPDL 2D Beam Example#
This is an example from the book “Finite element analysis using ansys 11.0” by Paletikrishna Chaitanya, Sambanarajesh Kumar, and Datti Srinivas. PHI Learning Pvt. Ltd., 1 Jan 2010.
Launch MAPDL with interactive plotting
from ansys.mapdl.core import launch_mapdl
mapdl = launch_mapdl()
mapdl.fcomp("rst", 0) # specify compression level
File compression level set to 0 for RST file(s).
Define an I-beam
mapdl.prep7()
mapdl.et(1, "BEAM188")
mapdl.keyopt(1, 4, 1) # transverse shear stress output
# material properties
mapdl.mp("EX", 1, 2e7) # N/cm2
mapdl.mp("PRXY", 1, 0.27) # Poisson's ratio
# beam properties in centimeters
sec_num = 1
mapdl.sectype(sec_num, "BEAM", "I", "ISection", 3)
mapdl.secoffset("CENT")
beam_info = mapdl.secdata(15, 15, 29, 2, 2, 1) # dimensions are in centimeters
Create nodes within MAPDL
mapdl.n(1, 0, 0, 0)
mapdl.n(12, 110, 0, 0)
mapdl.n(23, 220, 0, 0)
mapdl.fill(1, 12, 10)
mapdl.fill(12, 23, 10)
# list the node coordinates
print(mapdl.mesh.nodes)
# list the node numbers
print(mapdl.mesh.nnum)
# plot the nodes using VTK
mapdl.nplot(vtk=True, nnum=True, cpos="xy", show_bounds=True, point_size=10)
[[ 0. 0. 0.]
[ 10. 0. 0.]
[ 20. 0. 0.]
[ 30. 0. 0.]
[ 40. 0. 0.]
[ 50. 0. 0.]
[ 60. 0. 0.]
[ 70. 0. 0.]
[ 80. 0. 0.]
[ 90. 0. 0.]
[100. 0. 0.]
[110. 0. 0.]
[120. 0. 0.]
[130. 0. 0.]
[140. 0. 0.]
[150. 0. 0.]
[160. 0. 0.]
[170. 0. 0.]
[180. 0. 0.]
[190. 0. 0.]
[200. 0. 0.]
[210. 0. 0.]
[220. 0. 0.]]
[ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23]
create elements between the nodes we can just manually create elements since we know that the elements are sequential
LIST ALL SELECTED ELEMENTS. (LIST NODES)
*****MAPDL VERIFICATION RUN ONLY*****
DO NOT USE RESULTS FOR PRODUCTION
ELEM MAT TYP REL ESY SEC NODES
1 1 1 1 0 1 1 2 0
2 1 1 1 0 1 2 3 0
3 1 1 1 0 1 3 4 0
4 1 1 1 0 1 4 5 0
5 1 1 1 0 1 5 6 0
6 1 1 1 0 1 6 7 0
7 1 1 1 0 1 7 8 0
8 1 1 1 0 1 8 9 0
9 1 1 1 0 1 9 10 0
10 1 1 1 0 1 10 11 0
11 1 1 1 0 1 11 12 0
12 1 1 1 0 1 12 13 0
13 1 1 1 0 1 13 14 0
14 1 1 1 0 1 14 15 0
15 1 1 1 0 1 15 16 0
16 1 1 1 0 1 16 17 0
17 1 1 1 0 1 17 18 0
18 1 1 1 0 1 18 19 0
19 1 1 1 0 1 19 20 0
20 1 1 1 0 1 20 21 0
21 1 1 1 0 1 21 22 0
22 1 1 1 0 1 22 23 0
Access them as a list of arrays
See the documentation on mapdl.mesh.elem for interpreting the
individual elements
[1 1 1 1 0 0 0 0 1 0 1 2 0]
[1 1 1 1 0 0 0 0 2 0 2 3 0]
[1 1 1 1 0 0 0 0 3 0 3 4 0]
[1 1 1 1 0 0 0 0 4 0 4 5 0]
[1 1 1 1 0 0 0 0 5 0 5 6 0]
[1 1 1 1 0 0 0 0 6 0 6 7 0]
[1 1 1 1 0 0 0 0 7 0 7 8 0]
[1 1 1 1 0 0 0 0 8 0 8 9 0]
[ 1 1 1 1 0 0 0 0 9 0 9 10 0]
[ 1 1 1 1 0 0 0 0 10 0 10 11 0]
[ 1 1 1 1 0 0 0 0 11 0 11 12 0]
[ 1 1 1 1 0 0 0 0 12 0 12 13 0]
[ 1 1 1 1 0 0 0 0 13 0 13 14 0]
[ 1 1 1 1 0 0 0 0 14 0 14 15 0]
[ 1 1 1 1 0 0 0 0 15 0 15 16 0]
[ 1 1 1 1 0 0 0 0 16 0 16 17 0]
[ 1 1 1 1 0 0 0 0 17 0 17 18 0]
[ 1 1 1 1 0 0 0 0 18 0 18 19 0]
[ 1 1 1 1 0 0 0 0 19 0 19 20 0]
[ 1 1 1 1 0 0 0 0 20 0 20 21 0]
[ 1 1 1 1 0 0 0 0 21 0 21 22 0]
[ 1 1 1 1 0 0 0 0 22 0 22 23 0]
Define the boundary conditions
SPECIFIED NODAL LOAD FZ FOR SELECTED NODES 12 TO 12 BY 1
REAL= -22840.0000 IMAG= 0.00000000
run the static analysis
mapdl.run("/solu")
mapdl.antype("static")
print(mapdl.solve())
***** MAPDL SOLVE COMMAND *****
*** NOTE *** CP = 0.000 TIME= 00:00:00
There is no title defined for this analysis.
*** SELECTION OF ELEMENT TECHNOLOGIES FOR APPLICABLE ELEMENTS ***
---GIVE SUGGESTIONS ONLY---
ELEMENT TYPE 1 IS BEAM188 . KEYOPT(1)=1 IS SUGGESTED FOR NON-CIRCULAR CROSS
SECTIONS AND KEYOPT(3)=2 IS ALWAYS SUGGESTED.
ELEMENT TYPE 1 IS BEAM188 . KEYOPT(15) IS ALREADY SET AS SUGGESTED.
*****MAPDL VERIFICATION RUN ONLY*****
DO NOT USE RESULTS FOR PRODUCTION
S O L U T I O N O P T I O N S
PROBLEM DIMENSIONALITY. . . . . . . . . . . . .3-D
DEGREES OF FREEDOM. . . . . . UX UY UZ ROTX ROTY ROTZ
ANALYSIS TYPE . . . . . . . . . . . . . . . . .STATIC (STEADY-STATE)
GLOBALLY ASSEMBLED MATRIX . . . . . . . . . . .SYMMETRIC
*** NOTE *** CP = 0.000 TIME= 00:00:00
Present time 0 is less than or equal to the previous time. Time will
default to 1.
*** NOTE *** CP = 0.000 TIME= 00:00:00
The conditions for direct assembly have been met. No .emat or .erot
files will be produced.
D I S T R I B U T E D D O M A I N D E C O M P O S E R
...Number of elements: 22
...Number of nodes: 23
...Decompose to 0 CPU domains
...Element load balance ratio = 0.000
L O A D S T E P O P T I O N S
LOAD STEP NUMBER. . . . . . . . . . . . . . . . 1
TIME AT END OF THE LOAD STEP. . . . . . . . . . 1.0000
NUMBER OF SUBSTEPS. . . . . . . . . . . . . . . 1
STEP CHANGE BOUNDARY CONDITIONS . . . . . . . . NO
PRINT OUTPUT CONTROLS . . . . . . . . . . . . .NO PRINTOUT
DATABASE OUTPUT CONTROLS. . . . . . . . . . . .ALL DATA WRITTEN
FOR THE LAST SUBSTEP
*** NOTE *** CP = 0.000 TIME= 00:00:00
Predictor is ON by default for structural elements with rotational
degrees of freedom. Use the PRED,OFF command to turn the predictor
OFF if it adversely affects the convergence.
Range of element maximum matrix coefficients in global coordinates
Maximum = 2.504767151E+10 at element 0.
Minimum = 2.504767151E+10 at element 0.
*** ELEMENT MATRIX FORMULATION TIMES
TYPE NUMBER ENAME TOTAL CP AVE CP
1 22 BEAM188 0.000 0.000000
Time at end of element matrix formulation CP = 0.
DISTRIBUTED SPARSE MATRIX DIRECT SOLVER.
Number of equations = 44, Maximum wavefront = 0
Memory available (MB) = 0.0 , Memory required (MB) = 0.0
Distributed sparse solver maximum pivot= 0 at node 0 .
Distributed sparse solver minimum pivot= 0 at node 0 .
Distributed sparse solver minimum pivot in absolute value= 0 at node 0
.
*** ELEMENT RESULT CALCULATION TIMES
TYPE NUMBER ENAME TOTAL CP AVE CP
1 22 BEAM188 0.000 0.000000
*** NODAL LOAD CALCULATION TIMES
TYPE NUMBER ENAME TOTAL CP AVE CP
1 22 BEAM188 0.000 0.000000
*** LOAD STEP 1 SUBSTEP 1 COMPLETED. CUM ITER = 1
*** TIME = 1.00000 TIME INC = 1.00000 NEW TRIANG MATRIX
Stop mapdl#
mapdl.exit()
Total running time of the script: (0 minutes 0.692 seconds)