FreeCAD/src/Mod/Fem/ccxFrdReader.py
Przemo Firszt b516e35b19 FEM: Add frequency analysis to FEM wb
Signed-off-by: Przemo Firszt <przemo@firszt.eu>
2015-09-09 13:57:47 +02:00

284 lines
11 KiB
Python

#***************************************************************************
#* *
#* Copyright (c) 2013 - Joachim Zettler *
#* Copyright (c) 2013 - Juergen Riegel <FreeCAD@juergen-riegel.net> *
#* *
#* This program is free software; you can redistribute it and/or modify *
#* it under the terms of the GNU Lesser General Public License (LGPL) *
#* as published by the Free Software Foundation; either version 2 of *
#* the License, or (at your option) any later version. *
#* for detail see the LICENCE text file. *
#* *
#* This program is distributed in the hope that it will be useful, *
#* but WITHOUT ANY WARRANTY; without even the implied warranty of *
#* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
#* GNU Library General Public License for more details. *
#* *
#* You should have received a copy of the GNU Library General Public *
#* License along with this program; if not, write to the Free Software *
#* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
#* USA *
#* *
#***************************************************************************
import FreeCAD
import os
from math import pow, sqrt
__title__ = "FreeCAD Calculix library"
__author__ = "Juergen Riegel "
__url__ = "http://www.freecadweb.org"
if open.__module__ == '__builtin__':
pyopen = open # because we'll redefine open below
# read a calculix result file and extract the nodes, displacement vectores and stress values.
def readResult(frd_input):
frd_file = pyopen(frd_input, "r")
nodes = {}
elements = {}
results = []
mode_results = {}
mode_disp = {}
mode_stress = {}
mode_disp_found = False
nodes_found = False
mode_stress_found = False
elements_found = False
eigenmode = 0
elem = -1
elemType = 0
for line in frd_file:
#Check if we found nodes section
if line[4:6] == "2C":
nodes_found = True
#first lets extract the node and coordinate information from the results file
if nodes_found and (line[1:3] == "-1"):
elem = int(line[4:13])
nodes_x = float(line[13:25])
nodes_y = float(line[25:37])
nodes_z = float(line[37:49])
nodes[elem] = FreeCAD.Vector(nodes_x, nodes_y, nodes_z)
#Check if we found nodes section
if line[4:6] == "3C":
elements_found = True
#first lets extract element number
if elements_found and (line[1:3] == "-1"):
elem = int(line[4:13])
elemType = int(line[14:18])
#then the 10 id's for the Tet10 element
if elements_found and (line[1:3] == "-2") and elemType == 6:
node_id_2 = int(line[3:13])
node_id_1 = int(line[13:23])
node_id_3 = int(line[23:33])
node_id_4 = int(line[33:43])
node_id_5 = int(line[43:53])
node_id_7 = int(line[53:63])
node_id_6 = int(line[63:73])
node_id_9 = int(line[73:83])
node_id_8 = int(line[83:93])
node_id_10 = int(line[93:103])
elements[elem] = (node_id_1, node_id_2, node_id_3, node_id_4, node_id_5, node_id_6, node_id_7, node_id_8, node_id_9, node_id_10)
#Check if we found new eigenmode
if line[5:10] == "PMODE":
eigenmode = int(line[30:36])
#Check if we found displacement section
if line[5:9] == "DISP":
mode_disp_found = True
#we found a displacement line in the frd file
if mode_disp_found and (line[1:3] == "-1"):
elem = int(line[4:13])
mode_disp_x = float(line[13:25])
mode_disp_y = float(line[25:37])
mode_disp_z = float(line[37:49])
mode_disp[elem] = FreeCAD.Vector(mode_disp_x, mode_disp_y, mode_disp_z)
if line[5:11] == "STRESS":
mode_stress_found = True
#we found a displacement line in the frd file
if mode_stress_found and (line[1:3] == "-1"):
elem = int(line[4:13])
stress_1 = float(line[13:25])
stress_2 = float(line[25:37])
stress_3 = float(line[37:49])
stress_4 = float(line[49:61])
stress_5 = float(line[61:73])
stress_6 = float(line[73:85])
mode_stress[elem] = (stress_1, stress_2, stress_3, stress_4, stress_5, stress_6)
#Check for the end of a section
if line[1:3] == "-3":
if mode_disp_found:
mode_disp_found = False
if mode_stress_found:
mode_stress_found = False
if mode_disp and mode_stress:
mode_results = {}
mode_results['number'] = eigenmode
mode_results['disp'] = mode_disp
mode_results['stress'] = mode_stress
results.append(mode_results)
mode_disp = {}
mode_stress = {}
eigenmode = 0
nodes_found = False
elements_found = False
frd_file.close()
return {'Nodes': nodes, 'Tet10Elem': elements, 'Results': results}
def calculate_von_mises(i):
# Von mises stress (http://en.wikipedia.org/wiki/Von_Mises_yield_criterion)
s11 = i[0]
s22 = i[1]
s33 = i[2]
s12 = i[3]
s23 = i[4]
s31 = i[5]
s11s22 = pow(s11 - s22, 2)
s22s33 = pow(s22 - s33, 2)
s33s11 = pow(s33 - s11, 2)
s12s23s31 = 6 * (pow(s12, 2) + pow(s23, 2) * pow(s31, 2))
vm_stress = sqrt(0.5 * (s11s22 + s22s33 + s33s11 + s12s23s31))
return vm_stress
def importFrd(filename, Analysis=None):
m = readResult(filename)
result_set_number = len(m['Results'])
MeshObject = None
if(len(m) > 0):
import Fem
if Analysis is None:
AnalysisName = os.path.splitext(os.path.basename(filename))[0]
AnalysisObject = FreeCAD.ActiveDocument.addObject('Fem::FemAnalysis', 'Analysis')
AnalysisObject.Label = AnalysisName
else:
AnalysisObject = Analysis
if 'Nodes' in m:
positions = []
for k, v in m['Nodes'].iteritems():
positions.append(v)
p_x_max, p_y_max, p_z_max = map(max, zip(*positions))
p_x_min, p_y_min, p_z_min = map(min, zip(*positions))
x_span = abs(p_x_max - p_x_min)
y_span = abs(p_y_max - p_y_min)
z_span = abs(p_z_max - p_z_min)
span = max(x_span, y_span, z_span)
if ('Tet10Elem' in m) and ('Nodes' in m) and (not Analysis):
mesh = Fem.FemMesh()
nds = m['Nodes']
for i in nds:
n = nds[i]
mesh.addNode(n[0], n[1], n[2], i)
elms = m['Tet10Elem']
for i in elms:
e = elms[i]
mesh.addVolume([e[0], e[1], e[2], e[3], e[4], e[5], e[6], e[7], e[8], e[9]], i)
if len(nds) > 0:
MeshObject = FreeCAD.ActiveDocument.addObject('Fem::FemMeshObject', 'ResultMesh')
MeshObject.FemMesh = mesh
AnalysisObject.Member = AnalysisObject.Member + [MeshObject]
for result_set in m['Results']:
eigenmode_number = result_set['number']
if result_set_number > 1:
results_name = 'Mode_' + str(eigenmode_number) + '_results'
else:
results_name = 'Results'
results = FreeCAD.ActiveDocument.addObject('Fem::FemResultObject', results_name)
disp = result_set['disp']
l = len(disp)
displacement = []
for k, v in disp.iteritems():
displacement.append(v)
x_max, y_max, z_max = map(max, zip(*displacement))
if result_set_number > 1:
max_disp = max(x_max, y_max, z_max)
# Allow for max displacement to be 0.1% of the span
# FIXME - add to Preferences
max_allowed_disp = 0.001 * span
scale = max_allowed_disp / max_disp
else:
scale = 1.0
if len(disp) > 0:
results.DisplacementVectors = map((lambda x: x * scale), disp.values())
results.ElementNumbers = disp.keys()
if(MeshObject):
results.Mesh = MeshObject
stress = result_set['stress']
if len(stress) > 0:
mstress = []
for i in stress.values():
mstress.append(calculate_von_mises(i))
if result_set_number > 1:
results.StressValues = map((lambda x: x * scale), mstress)
else:
results.StressValues = mstress
if (results.ElementNumbers != 0 and results.ElementNumbers != stress.keys()):
print ("Inconsistent FEM results: element number for Stress doesn't equal element number for Displacement {} != {}"
.format(results.ElementNumbers, len(results.StressValues)))
results.ElementNumbers = stress.keys()
x_min, y_min, z_min = map(min, zip(*displacement))
sum_list = map(sum, zip(*displacement))
x_avg, y_avg, z_avg = [i / l for i in sum_list]
s_max = max(results.StressValues)
s_min = min(results.StressValues)
s_avg = sum(results.StressValues) / l
disp_abs = []
for d in displacement:
disp_abs.append(sqrt(pow(d[0], 2) + pow(d[1], 2) + pow(d[2], 2)))
results.DisplacementLengths = disp_abs
a_max = max(disp_abs)
a_min = min(disp_abs)
a_avg = sum(disp_abs) / l
results.Stats = [x_min, x_avg, x_max,
y_min, y_avg, y_max,
z_min, z_avg, z_max,
a_min, a_avg, a_max,
s_min, s_avg, s_max]
AnalysisObject.Member = AnalysisObject.Member + [results]
if(FreeCAD.GuiUp):
import FemGui
import FreeCADGui
if FreeCADGui.activeWorkbench().name() != 'FemWorkbench':
FreeCADGui.activateWorkbench("FemWorkbench")
FemGui.setActiveAnalysis(AnalysisObject)
def insert(filename, docname):
"called when freecad wants to import a file"
try:
doc = FreeCAD.getDocument(docname)
except NameError:
doc = FreeCAD.newDocument(docname)
FreeCAD.ActiveDocument = doc
importFrd(filename)
def open(filename):
"called when freecad opens a file"
docname = os.path.splitext(os.path.basename(filename))[0]
insert(filename, docname)