How can I filter all nodes / elements above a certain result threshold using DPF / PyDPF?

Ayush Kumar

How can I filter all nodes / elements above a certain result threshold using DPF / PyDPF?

Ayush Kumar

The following script filters all nodes above a value of 0.3mm total deformation and finds all the elements connected to those nodes.

PyDPF

from ansys.dpf import core as dpf

rst_path = r"\Path\to\file.rst"
ds = dpf.DataSources(rst_path)

crit_disp = 0.3

model = dpf.Model(ds)
mesh = model.metadata.meshed_region

mesh.plot()

all_elems = mesh.elements.scoping.ids
disp = model.results.displacement()
disp_norm = dpf.operators.math.norm_fc(disp)

filt_disp = dpf.operators.filter.field_high_pass_fc(fields_container=disp_norm, threshold=crit_disp)
nodes_crit = filt_disp.outputs.fields_container.get_data()[0].scoping.ids

elements = []
mesh_con = mesh.property_field("reverse_connectivity")
for node in nodes_crit:
    elements.append(mesh_con.get_entity_data_by_id(node))

# Flatten the list #
elem_crit_indexes = list(set([element for nested_elements in elements for element in nested_elements]))
elem_crit_ids = [mesh.elements.scoping.ids[eid] for eid in elem_crit_indexes]

elem_crit_scop = dpf.Scoping()
elem_crit_scop.ids = elem_crit_ids

crit_mesh = dpf.operators.mesh.from_scoping(mesh=mesh, scoping=elem_crit_scop).outputs.mesh.get_data()
crit_mesh.plot()

Mechanical DPF (IronPython)

import mech_dpf
import Ans.DataProcessing as dpf
mech_dpf.setExtAPI(ExtAPI)

analysis = Model.Analyses[0]
ds = dpf.DataSources(analysis.ResultFileName)

crit_disp = 0.3

model = dpf.Model(ds)
mesh = model.Mesh
all_elems = mesh.ElementIds
disp = model.results.displacement()
disp_norm = dpf.operators.math.norm_fc(disp)

filt_disp = dpf.operators.filter.field_high_pass_fc(fields_container=disp_norm, threshold=crit_disp)
nodes_crit = filt_disp.outputs.fields_container.GetData()[0].ScopingIds

elements = []

mesh_con = mesh.NodalConnectivityPropertyField
for node in nodes_crit:
    elements.append(mesh_con.GetEntityDataById(node))

elem_crit = list(set([all_elems[elem_index] for elem_list in elements for elem_index in elem_list]))

elem_crit_scop = dpf.Scoping()
elem_crit_scop.Ids = elem_crit

Pernelle Marone-Hitz

To add to @Ayush Kumar 's solution, if you want to plot the filtered element numbers back to the model in Mechanical, this can be done in a Python Result Object.

Edit Property Provider as follows:

def reload_props():

this.PropertyProvider = None

# Create the property instance

provider = Provider()
group = provider.AddGroup("Inputs")


double_prop = group.AddProperty("Threshold", Control.Double)


# Connects the provider instance back to the object by setting the PropertyProvider member on this, 'this' being the 

# current instance of the Python Code object.

this.PropertyProvider = provider

Edit Script as follows:

def define_dpf_workflow(analysis):

import mech_dpf

import Ans.DataProcessing as dpf

mech_dpf.setExtAPI(ExtAPI)
ds = dpf.DataSources(analysis.ResultFileName)


crit_disp =  this.GetCustomPropertyByPath("Inputs/Threshold").Value



model = dpf.Model(ds)

mesh = model.Mesh

all_elems = mesh.ElementIds


disp = model.results.displacement()

disp_norm = dpf.operators.math.norm_fc(disp)


filt_disp = dpf.operators.filter.field_high_pass_fc(fields_container=disp_norm, threshold=crit_disp)

nodes_crit = filt_disp.outputs.fields_container.GetData()[0].ScopingIds


elements = []


mesh_con = mesh.NodalConnectivityPropertyField

for node in nodes_crit:

    elements.append(mesh_con.GetEntityDataById(node))


elem_crit = list(set([all_elems[elem_index] for elem_list in elements for elem_index in elem_list]))


elem_crit_scop = dpf.Scoping()

elem_crit_scop.Ids = elem_crit


# create new field and assign values

my_field = dpf.FieldsFactory.CreateScalarField(numEntities=0, location='Elemental')

my_field.MeshedRegionSupport = mesh

for elem_id in elem_crit_scop.Ids:

    my_field.Add(elem_id,[float(elem_id)])

my_field.ScopingIds = elem_crit_scop.Ids


output = dpf.operators.utility.forward()

output.inputs.any.Connect(my_field)


dpf_workflow = dpf.Workflow()

dpf_workflow.Add(output)

dpf_workflow.SetOutputContour(output,dpf.enums.GFXContourType.FEElementalScoping)

dpf_workflow.Record('wf_id', False)

this.WorkflowId = dpf_workflow.GetRecordedId()

Reload properties and evaluate result:

This will plot the element number on the filtered elements: