Export a CSV with Element ID and nodal averaged stress of the element face in WB LS-Dyna.

Ayush Kumar

Export a CSV with Element ID and nodal averaged stress of the element face in WB LS-Dyna.

Ayush Kumar

DPF can be used in Python-Code object to export a CSV After Post for the above mentioned request.
Pre-requisites:

• Named Selection of all the Element faces.
• 2022R2 and above

Copy the following in the Script part of the Python Code object:

def after_post(this, solution):# Do not edit this line
    import os
    import json
    import mech_dpf
    import Ans.DataProcessing as dpf

    mesh = ExtAPI.DataModel.MeshDataByName("Global")
    ns_name = this.GetCustomPropertyByPath("Named Selection/Name").Value
    element = ExtAPI.DataModel.GetObjectsByName(ns_name)[0]
    element_face_indices = element.ElementFaceIndices

    el_face_nodes = {}
    all_nodes = []

    ElementFaceWrapper = Ansys.ACT.Common.Mesh.ElementFaceWrapper
    for id, index in zip(element.Ids, element_face_indices):
        el_face = ElementFaceWrapper(mesh, mesh.ElementById(id), index)
        nids = el_face.NodeIds
        el_face_nodes.update({id: nids})
        all_nodes += nids

    mech_dpf.setExtAPI(ExtAPI)

    analysis = Model.Analyses[0]
    d3plot_path = os.path.join(analysis.WorkingDir, "d3plot")
    act_units_path = os.path.join(analysis.WorkingDir, "file.actunits")

    ds = dpf.DataSources()
    ds.SetResultFilePath(d3plot_path, "d3plot")
    ds.AddFilePath(act_units_path, "actunits")
    model = dpf.Model(ds)

    ts = dpf.Scoping()
    ts.Ids = [int(this.GetCustomPropertyByPath("Time History Results/Result at Set Number").Value)]

    ms = dpf.Scoping()
    ms.Ids = list(set(all_nodes))

    sx = dpf.operators.result.stress_X(time_scoping=ts,
                                       requested_location=dpf.locations.nodal,
                                       data_sources=ds)
    sx_f = sx.outputs.fields_container.GetData()[0]

    file_path = os.path.join(analysis.WorkingDir, "el_face_avg.csv")

    if os.path.isfile(file_path):
    # if exists, delete the file
        os.remove(file_path)

    with open(file_path, 'w') as file:
        file.write("EID; Element Face Average")
        file.write("\n")
        el_face_print = el_face_nodes.copy()
        for eid, nids in el_face_nodes.iteritems():
            sx_avg = sum([sx_f.GetEntityDataById(nid)[0] for nid in nids]) / len(nids)
            el_face_print.update({eid: [nids, sx_avg]})
            file.write("{0}".format(eid))
            file.write("; ")
            file.write("{0}".format(sx_avg))
            file.write("\n")


    return

Replace the reload_props function with the following in Property Provider:

def reload_props():
    provider = Provider()
    group_one = provider.AddGroup("Time History Results")
    SetNum = group_one.AddProperty("Result at Set Number", Control.Double)
    SetNum.Value = 1 # Default set value

    group_two = provider.AddGroup("Named Selection")
    ns = group_two.AddProperty("Name", Control.Expression)
    this.PropertyProvider = provider