Adding new example : dynamic simulation of PCB

examples/07-technology-showcase-examples/20-example-technology-showcase-dynamic-simulation-PCB.py

@@ -0,0 +1,278 @@
+""".. _ref_dynamic_simulation_printed_circuit_board:
+
+Dynamic simulation of a printed circuit board assembly
+------------------------------------------------------
+
+This examples shows how to use PyMAPDL to import an existing FE model and to
+run a modal and PSD analysis. PyDPF modules are also used for post-processing.
+
+This example is inspired from the model and analysis defined in Chapter 20 of
+the Mechanical APDL Technology Showcase Manual.
+
+Additional Packages Used
+~~~~~~~~~~~~~~~~~~~~~~~~
+* `Matplotlib <https://matplotlib.org>`_ is used for plotting purposes.
+
+"""
+
+###############################################################################
+# Starting MAPDL as a service and importing an external model
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# The original FE model is given in the Ansys Mechanical APDL Technology Showcase Manual.
+# The .cdb contains a FE model of a single circuit board. The model is meshed
+# with SOLID186, SHELL181 and BEAM188 elements. All components of the PCB
+# model is assigned with linear elastic isotropic materials. Bonded and
+# flexible surface-to-surface contact pairs are used to define the contact
+# between the IC packages and the circuit board.
+
+
+import matplotlib.pyplot as plt
+
+from ansys.mapdl.core import launch_mapdl
+from ansys.mapdl.core.examples import download_tech_demo_data
+
+# start MAPDL as a service
+mapdl = launch_mapdl()
+print(mapdl)
+
+# read model of single circuit board
+# download the cdb file
+pcb_mesh_file = download_tech_demo_data("td-20", "pcb_mesh_file.cdb")
+
+# enter preprocessor and read in cdb
+mapdl.prep7()
+mapdl.cdread("COMB", pcb_mesh_file)
+mapdl.allsel()
+mapdl.eplot(background="w")
+mapdl.cmsel("all")
+
+###############################################################################
+# Creating the complete layered model
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# The original model will be duplicated to create a layered PCB of three layers
+# that are binded together
+
+# duplicate single PCB to get three layers
+#  get the maximum node number for the single layers PCB in the input file
+max_nodenum = mapdl.get("max_nodenum", "node", " ", "num", "max")
+
+# generate additional PCBs offset by 20 mm in the -y direction
+mapdl.egen("3", max_nodenum, "all", dy="-20")
+
+
+# bind the three layers together
+# select components of interest
+mapdl.cmsel("s", "N_JOINT_BOARD")
+mapdl.cmsel("a", "N_JOINT_LEGS")
+mapdl.cmsel("a", "N_BASE")
+
+# get number of currently selected nodes
+nb_selected_nodes = mapdl.mesh.n_node
+current_node = 0
+queries = mapdl.queries
+
+# also select similar nodes for copies of the single PCB
+# and couple all dofs at the interface
+for node_id in range(1, nb_selected_nodes + 1):
+    current_node = queries.ndnext(current_node)
+    mapdl.nsel("a", "node", " ", current_node + max_nodenum)
+    mapdl.nsel("a", "node", " ", current_node + 2 * max_nodenum)
+mapdl.cpintf("all")
+
+# define fixed support boundary condition
+# get max coupled set number
+cp_max = mapdl.get("cp_max", "cp", "0", "max")
+
+# unselect nodes scoped in CP equations
+mapdl.nsel("u", "cp", " ", "1", "cp_max")
+
+# create named selection for base excitation
+mapdl.cm("n_base_excite", "node")
+
+# fix displacement for base excitation nodes
+mapdl.d("all", "all")
+
+# select all and plot the model using MAPDL's plotter and VTK's
+mapdl.allsel("all")
+mapdl.cmsel("all")
+mapdl.graphics("power")
+mapdl.rgb("index", "100", "100", "100", "0")
+mapdl.rgb("index", "80", "80", "80", "13")
+mapdl.rgb("index", "60", "60", "60", "14")
+mapdl.rgb("index", "0", "0", "0", "15")
+mapdl.triad("rbot")
+mapdl.pnum("type", "1")
+mapdl.number("1")
+mapdl.hbc("1", "on")
+mapdl.pbc("all", " ", "1")
+mapdl.view(1, 1, 1, 1)
+mapdl.eplot(vtk=False)
+mapdl.eplot(vtk=True)
+
+###############################################################################
+# Run a modal analysis
+# ~~~~~~~~~~~~~~~~~~~~~~~
+#
+
+# enter solution processor and define analysis settings
+mapdl.slashsolu()
+mapdl.antype("modal")
+# set number of modes to extract
+# using a higher number of modes is recommended
+nb_modes = 10
+# use Block Lanzos to extract specified number of modes
+mapdl.modopt("lanb", nb_modes)
+mapdl.mxpand(nb_modes)
+output = mapdl.solve()
+print(output)
+
+
+###############################################################################
+# Post-processing the modal results
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# This sections illustrates different methods to post-process the results of the
+# modal analysis : PyMAPDL method, PyMAPDL result reader, PyDPF-Post
+# and PyDPF-Core. All methods lead to the same result and are just given as an
+# example of how each module can be used.
+
+# using MAPDL methods
+mapdl.post1()
+mapdl.set(1, 1)
+mapdl.plnsol("u", "sum")
+
+# using PyMAPDL result reader
+mapdl_result = mapdl.result
+mapdl_result.plot_nodal_displacement(0)
+
+###############################################################################
+# Using DPF-Post
+# ~~~~~~~~~~~~~~
+# from ansys.dpf import post
+# solution_path = 'file.rst'
+# solution = post.load_solution(solution_path)
+# print(solution)
+# displacement = solution.displacement(time_scoping=1)
+# total_deformation = displacement.norm
+# total_deformation.plot_contour(show_edges=True)
+
+# using DPF-Core
+# from ansys.dpf import core
+# model = core.Model(solution_path)
+# results = model.results
+# print(results)
+# displacements = results.displacement()
+# total_def = core.operators.math.norm_fc(displacements)
+# total_def_container = total_def.outputs.fields_container()
+# mesh = model.metadata.meshed_region
+# mesh.plot(total_def_container.get_field_by_time_id(1))
+
+###############################################################################
+# PSD analysis
+# ~~~~~~~~~~~~~
+# The response spectrum analysis is defined, solved and post-processed
+
+# define PSD analysis with input spectrum
+mapdl.slashsolu()
+mapdl.antype("spectr")
+
+# power spectral density
+mapdl.spopt("psd")
+
+# use input table 1 with acceleration spectrum in terms of acceleration due to gravity
+mapdl.psdunit(1, "accg", 9.81 * 1000)
+
+# define the frequency points in the input table 1
+mapdl.psdfrq(1, " ", 1, 40, 50, 70.71678, 100, 700, 900)
+
+# define the PSD values in the input table 1
+mapdl.psdval(1, 0.01, 0.01, 0.1, 1, 10, 10, 1)
+
+# set the damping ratio as 5%
+mapdl.dmprat(0.05)
+
+# apply base excitation on the set of nodes N_BASE_EXCITE in the y-direction from table 1
+mapdl.d("N_BASE_EXCITE", "uy", 1)
+
+# calculate the participation factor for PSD with base excitation from input table 1
+mapdl.pfact(1, "base")
+
+# write the displacent solution relative to the base excitation to the results file from the PSD analysis
+mapdl.psdres("disp", "rel")
+
+# write the absolute velocity solution to the results file from the PSD analysis
+mapdl.psdres("velo", "abs")
+
+# write the absolute acceleration solution to the results file from the PSD analysis
+mapdl.psdres("acel", "abs")
+
+# combine only those modes whose significance level exceeds 0.0001
+mapdl.psdcom()
+output = mapdl.solve()
+print(output)
+
+###############################################################################
+# Post-process PSD analysis
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+# Using MAPDL methods in POST1
+mapdl.post1()
+mapdl.set(1, 1)
+mapdl.plnsol("u", "sum")
+mapdl.set("last")
+mapdl.plnsol("u", "sum")
+
+# Using MAPDL methods in POST26 (time-history post-processing)
+mapdl.post26()
+
+# allow storage for 200 variables
+mapdl.numvar(200)
+mapdl.cmsel("s", "MY_MONITOR")
+monitored_node = mapdl.queries.ndnext(0)
+mapdl.store("psd")
+
+# store the psd analysis u_y data for the node MYMONITOR as the reference no 2
+mapdl.nsol(2, monitored_node, "u", "y")
+
+# compute the response power spectral density for displacement associated with variable 2
+mapdl.rpsd(3, 2)
+mapdl.show("png")
+
+# plot the variable 3
+mapdl.plvar(3)
+
+# print the variable 3
+mapdl.prvar(3)
+
+# x-axis is set for Log X scale
+mapdl.gropt("logx", 1)
+
+# y-axis is set for Log X scale
+mapdl.gropt("logy", 1)
+
+# plot the variable 3
+mapdl.plvar(3)
+mapdl.show("close")
+
+###############################################################################
+# Plot using python libraries
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# store MAPDL results to python variables
+mapdl.dim("frequencies", "array", 4000, 1)
+mapdl.dim("response", "array", 4000, 1)
+mapdl.vget("frequencies(1)", 1)
+mapdl.vget("response(1)", 3)
+frequencies = mapdl.parameters["frequencies"]
+response = mapdl.parameters["response"]
+
+# use Matplotlib to create graph
+
+fig = plt.figure()
+ax = fig.add_subplot(111)
+plt.xscale("log")
+plt.yscale("log")
+ax.plot(frequencies, response)
+ax.set_xlabel("Frequencies")
+ax.set_ylabel("Response power spectral density")
+
+###############################################################################
+# Exit MAPDL
+mapdl.exit()

examples/07-technology-showcase-examples/README.txt

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+Technology Showcase Manual Examples
+====================================
+This section demonstrates  the broad simulation capabilities
+of Ansys Mechanical APDL. The problems demonstrate how 
+to use PyMAPDL to effectively and accurately
+solve interdisciplinary problems 
+from a variety of industries and engineering fields.

examples/README.txt

@@ -17,4 +17,5 @@ Here are a series of examples using MAPDL with ``ansys-mapdl-core``.
    01-apdlmath-examples\README.txt
    02-geometry\README.txt
    03-tips-n-tricks\README.txt
-   05-Tech_demos\README.txt
+   05-Tech_demos\README.txt
+   07-technology-showcase-examples\README.txt