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

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(nnum=True, cpos="xy", show_bounds=True, point_size=10)

create elements between the nodes we can just manually create elements since we know that the elements are sequential

for node in mapdl.mesh.nnum[:-1]:
    mapdl.e(node, node + 1)

# print the elements from MAPDL
print(mapdl.elist())

Access them as a list of arrays See the documentation on mapdl.mesh.elem for interpreting the individual elements

for elem in mapdl.mesh.elem:
    print(elem)

Define the boundary conditions

# Allow movement only in the X and Z direction
for const in ["UX", "UY", "ROTX", "ROTZ"]:
    mapdl.d("all", const)

# constrain just nodes 1 and 23 in the Z direction
mapdl.d(1, "UZ")
mapdl.d(23, "UZ")

# apply a -Z force at node 12
mapdl.f(12, "FZ", -22840)

run the static analysis

mapdl.run("/solu")
mapdl.antype("static")
print(mapdl.solve())

Stop mapdl

mapdl.exit()