"""
defines:
- tecplot = nastran_to_tecplot(model)
- tecplot = nastran_to_tecplot_filename(bdf_filename, tecplot_filename, z
log=None, debug=False)
"""
import numpy as np
from pyNastran.bdf.bdf import BDF
from pyNastran.converters.tecplot.tecplot import Tecplot, Zone
[docs]
def nastran_to_tecplot(model):
"""assumes sequential nodes"""
tecplot = Tecplot(log=model.log)
nnodes = len(model.nodes)
inode_max = max(model.nodes)
if nnodes == inode_max:
xyz = np.zeros((nnodes, 3), dtype='float64')
i = 0
for unused_nid, node in sorted(model.nodes.items()):
xyz[i, :] = node.get_position()
i += 1
else:
msg = 'sequential node IDs required; nnodes=%s inode_max=%s' % (
nnodes, inode_max)
raise RuntimeError(msg)
zone = Zone(model.log)
zone.headers_dict['VARIABLES'] = ['X', 'Y', 'Z']
zone.zone_data = xyz
nquads = model.card_count['CQUAD4'] if 'CQUAD4' in model.card_count else 0
ntets = model.card_count['CTETRA'] if 'CTETRA' in model.card_count else 0
#ntrias = model.card_count['CTRIA3'] if 'CTRIA3' in model.card_count else 0
nhexas = model.card_count['CHEXA'] if 'CHEXA' in model.card_count else 0
nelements = len(model.elements)
tris = []
quads = []
tets = []
hexas = []
pentas = []
#i = 0
#pids = np.zeros(nelements, dtype='int32')
#mids = np.zeros(nelements, dtype='int32')
unhandled_types = set()
for unused_eid, element in model.elements.items():
if element.type in ['CTRIA3']:
tris.append(element.node_ids)
elif element.type in ['CQUAD4']:
quads.append(element.node_ids)
elif element.type == 'CTETRA':
tets.append(element.node_ids[:4])
elif element.type == 'CPENTA':
pentas.append(element.node_ids[:6])
elif element.type == 'CHEXA':
hexas.append(element.node_ids[:8])
else:
unhandled_types.add(element.type)
#pid = element.Pid()
#mid = element.Mid()
#pids[i] = pid
#mids[i] = mid
#i += 1
for etype in unhandled_types:
print('ignoring %s' % etype)
# only supports nodal results
#tecplot.nodal_results = vstack([pids, mids])#.T
#print(tecplot.nodal_results.shape)
#tecplot.result_names = ['PropertyID', 'MaterialID']
ntris = len(tris)
nquads = len(quads)
nshells = ntris + nquads
ntets = len(tets)
npentas = len(pentas)
nhexas = len(hexas)
nsolids = ntets + npentas + nhexas
nnot_tris = nquads
nnot_quads = ntris
nnot_tets = npentas + nhexas
nnot_hexas = ntets + npentas
if ntris and not nnot_tris and not nsolids:
zone.tri_elements = np.array(tris, dtype='int32')
zone_type = 'FETRIANGLE'
elif nquads and not nnot_quads and not nsolids:
zone.quad_elements = np.array(quads, dtype='int32')
zone_type = 'FEQUADRILATERAL'
elif ntets and not nnot_tets and not nshells:
zone.tet_elements = np.array(tets, dtype='int32')
zone_type = 'FETETRAHEDRON'
elif nhexas and not nnot_hexas and not nshells:
zone.hexa_elements = np.array(hexas, dtype='int32')
zone_type = 'FEBRICK'
elif not nshells:
elements = np.zeros((nelements, 8), dtype='int32')
if ntets:
tets = np.array(tets, dtype='int32')
elements[:ntets, :4] = tets
elements[:ntets, 4] = elements[:ntets, 3]
elements[:ntets, 5] = elements[:ntets, 3]
elements[:ntets, 6] = elements[:ntets, 3]
elements[:ntets, 7] = elements[:ntets, 3]
if npentas:
# penta6
pentas = np.array(pentas, dtype='int32')
elements[ntets:ntets + npentas, :6] = pentas
elements[ntets:ntets + npentas, 6] = elements[:ntets, 5]
elements[ntets:ntets + npentas, 7] = elements[:ntets, 5]
if nhexas:
hexas = np.array(hexas, dtype='int32')
elements[ntets + npentas:ntets + npentas + nhexas, :6] = pentas
elements[ntets + npentas:ntets + npentas + nhexas, 6] = elements[:ntets, 5]
elements[ntets + npentas:ntets + npentas + nhexas, 7] = elements[:ntets, 5]
zone.hexa_elements = np.array(elements)
zone_type = 'FEBRICK'
elif not nsolids:
elements = np.zeros((nelements, 4), dtype='int32')
tris = np.array(tris, dtype='int32')
elements[:ntris, :3] = tris
elements[:ntris, 4] = elements[:ntets, 3]
quads = np.array(quads, dtype='int32')
elements[ntris:, :] = quads
zone_type = 'FEQUADRILATERAL'
else:
msg = 'Only solids or shells are allowed (not both)\n'
msg += ' nsolids=%s nshells=%s\n' % (nsolids, nshells)
msg += ' ntris=%s nquads=%s\n' % (ntris, nquads)
msg += ' ntets=%s npentas=%s nhexas=%s\n' % (ntets, npentas, nhexas)
raise NotImplementedError(msg)
zone.headers_dict['ZONETYPE'] = zone_type
tecplot.zones = [zone]
str(zone)
return tecplot
[docs]
def nastran_to_tecplot_filename(bdf_filename, tecplot_filename, log=None, debug=False):
"""converts a BDF file to Tecplot format; supports solid elements"""
model = BDF(log=log, debug=debug)
model.read_bdf(bdf_filename)
# tecplot = nastran_to_tecplot(model)
#log.info('card_count = %s' % model.card_count)
nnodes = len(model.nodes)
nodes = np.zeros((nnodes, 3), dtype='float64')
i = 0
nodeid_to_i_map = {}
for node_id, node in sorted(model.nodes.items()):
xyz = node.get_position()
nodes[i, :] = xyz
nodeid_to_i_map[node_id] = i
i += 1
assert len(model.nodes) == i, 'model.nodes=%s i=%s' % (len(model.nodes), i)
elements_list = []
zone_type = 'FEBRICK'
for unused_eid, element in sorted(model.elements.items()):
if element.type in ['CTETRA']:
n1, n2, n3, n4 = element.node_ids
i1, i2, i3, i4 = (nodeid_to_i_map[n1], nodeid_to_i_map[n2],
nodeid_to_i_map[n3], nodeid_to_i_map[n4])
elements_list.append([i1, i2, i3, i4,
i4, i4, i4, i4])
elif element.type in ['CPENTA']:
n1, n2, n3, n4, n5, n6 = element.node_ids
i1, i2, i3, i4, i5, i6 = (
nodeid_to_i_map[n1], nodeid_to_i_map[n2], nodeid_to_i_map[n3], nodeid_to_i_map[n4],
nodeid_to_i_map[n5], nodeid_to_i_map[n6])
elements_list.append([i1, i2, i3, i4,
i5, i6, i6, i6])
elif element.type in ['CPYRAM']:
n1, n2, n3, n4, n5 = element.node_ids
i1, i2, i3, i4, i5 = (
nodeid_to_i_map[n1], nodeid_to_i_map[n2], nodeid_to_i_map[n3], nodeid_to_i_map[n4],
nodeid_to_i_map[n5])
elements_list.append([i1, i2, i3, i4,
i5, i5, i5, i5])
elif element.type in ['CHEXA']:
n1, n2, n3, n4, n5, n6, n7, n8 = element.node_ids
i1, i2, i3, i4, i5, i6, i7, i8 = (
nodeid_to_i_map[n1], nodeid_to_i_map[n2], nodeid_to_i_map[n3], nodeid_to_i_map[n4],
nodeid_to_i_map[n5], nodeid_to_i_map[n6], nodeid_to_i_map[n7], nodeid_to_i_map[n8])
elements_list.append([i1, i2, i3, i4,
i5, i6, i7, i8])
else:
model.log.info('skip etype=%r' % element.type)
model.log.info(element)
elements = np.array(elements_list, dtype='int32')
tecplot = Tecplot(log=model.log)
zone = Zone(model.log)
zone.headers_dict['ZONETYPE'] = zone_type
zone.headers_dict['VARIABLES'] = ['X', 'Y', 'Z']
zone.zone_data = nodes
zone.hexa_elements = elements
tecplot.zones = [zone]
str(zone)
tecplot.write_tecplot(tecplot_filename)
return tecplot