Example: Python script for a connecting rod¶
Connecting rod
Steps¶
Model creation¶
import math
import geompy
import hexablock
doc = hexablock.addDocument("bielle")
# ------------------------------------- Build 2 cylindrical grids
centre_pb = doc.addVertex(0, 0, 0)
centre_gb = doc.addVertex(7, 0, 0)
angle_px = math.pi / 3
vecteur_px = doc.addVector(math.cos(angle_px), math.sin(angle_px), 0)
vecteur_gx = doc.addVector(1, 0, 0)
vecteur_z = doc.addVector(0, 0, 1)
grille_p = doc.makeCylindrical(centre_pb, vecteur_px, vecteur_z, 1, 360, 1, 1, 3, 1, False)
grille_g = doc.makeCylindrical(centre_gb, vecteur_gx, vecteur_z, 1, 360, 1, 1, 3, 1, False)
# ------------------------------------- Join the grids
quad_p = grille_p.getQuadJK(1, 2, 0)
quad_g = grille_g.getQuadJK(1, 1, 0)
point_p1 = grille_p.getVertexIJK(1, 0, 0)
point_p2 = grille_p.getVertexIJK(1, 2, 0)
point_g1 = grille_g.getVertexIJK(1, 1, 0)
point_g2 = grille_g.getVertexIJK(1, 2, 0)
prisme = doc.joinQuad(quad_p, quad_g, point_p1, point_g1,
point_p2, point_g2, 3)
Go back to Steps
Recovering edges and faces from geometry before the association¶
bielle = geompy.ImportSTEP("bielle.stp")
sommets = geompy.SubShapeAllSortedCentres(bielle, geompy.ShapeType["VERTEX"])
sommets_petit = [ 6, 8, 7, 9 ]
sommets_grand = [ 10, 12, 11, 13 ]
aretes = geompy.SubShapeAllSortedCentres(bielle, geompy.ShapeType["EDGE"])
aretes_petit = [ 7, 9, 8, 10 ]
aretes_grand = [ 19, 21, 20, 22 ]
ga_pbcd = aretes[ 0]
ga_pbe = aretes[ 2]
ga_phcd = aretes[ 1]
ga_phe = aretes[ 3]
ga_gbcd = aretes[27]
ga_gbe = aretes[25]
ga_ghcd = aretes[28]
ga_ghe = aretes[26]
Go back to Steps
Association of the model to the geometry¶
doc.setShape(bielle)
# ---------------------------- Clean implicit associations of the model
doc.clearAssociation()
# -------------------------- Procedure who associates external circles
def cercle(grille, k, ge, p):
ms = grille.getVertexIJK(0, 0, k)
ma1 = grille.getEdgeJ(0, 2, k)
ma2 = grille.getEdgeJ(0, 1, k)
ma3 = grille.getEdgeJ(0, 0, k)
doc.associateClosedLine(ms, ma1, [ ma2, ma3 ], ge, p, False, [])
cercle(grille_p, 0, ga_pbe, 5.0/6)
cercle(grille_p, 1, ga_phe, 5.0/6)
cercle(grille_g, 0, ga_gbe, 0)
cercle(grille_g, 1, ga_ghe, 0)
# ------------------- Procedure who associates external decentered lines
def arc(grille, i1, i2, k, ge):
ma1 = grille.getEdgeJ(1, i1, k)
ma2 = grille.getEdgeJ(1, i2, k)
doc.associateOpenedLine(ma1, [ ma2 ], ge, 0, [], 1)
arc(grille_p, 1, 0, 0, ga_pbcd)
arc(grille_p, 1, 0, 1, ga_phcd)
arc(grille_g, 0, 2, 0, ga_gbcd)
arc(grille_g, 0, 2, 1, ga_ghcd)
# ---------------------- Associate archs vertices with connection circles
hm = prisme.getHexa(1)
for i in xrange(0, 4):
vm = hm.getVertex(i)
ga = sommets[ sommets_petit[i] ]
vm.setAssociation(ga)
hm = prisme.getHexa(2)
for i in xrange(0, 4):
vm = hm.getVertex(i)
ga = sommets[ sommets_grand[i] ]
vm.setAssociation(ga)
# ---------------------- Associate connection circles
hm = prisme.getHexa(0)
for i in xrange(0, 4):
em = hm.getEdge(i+8)
ga = aretes[ aretes_petit[i] ]
em.addAssociation(ga, 0, 1)
hm = prisme.getHexa(2)
for i in xrange(0, 4):
em = hm.getEdge(i+8)
ga = aretes[ aretes_grand[i] ]
em.addAssociation(ga, 0, 1)
# --------------------- Round implicit cylindrical associations
for h, i, ech in [ [0, 0, 0.95], [0, 1, 0.95], [2, 2, 0.85], [2, 3, 0.85] ]:
hm = prisme.getHexa(h)
em = hm.getEdge(i)
va = em.getVertex(0).getAssociation()
vb = em.getVertex(1).getAssociation()
vax, vay, vaz = geompy.PointCoordinates(va)
vbx, vby, vbz = geompy.PointCoordinates(vb)
vmx = ( vax + vbx ) / 2.0 * ech
vmy = ( vay + vby ) / 2.0
vmz = ( vaz + vbz ) / 2.0
vm = geompy.MakeVertex(vmx, vmy, vmz)
eg = geompy.MakeArc(va, vm, vb)
em.clearAssociation()
em.addAssociation(eg, 0, 1)
Go back to Steps
Definition of elements groups for the mesh¶
# -------------------------- # Define 5 faces groups
groupe_petit = doc.addQuadGroup("Petit")
groupe_grand = doc.addQuadGroup("Grand")
groupe_bas = doc.addQuadGroup("Bas")
groupe_haut = doc.addQuadGroup("Haut")
groupe_contour = doc.addQuadGroup("Contour")
# -------------------------- Define little and big cylinder groups
for i in xrange(3):
groupe_petit.addElement( grille_p.getQuadJK(0, i, 0) )
groupe_grand.addElement( grille_g.getQuadJK(0, i, 0) )
# -------------------------- Define bottum and up groups
for i in xrange(3):
groupe_bas.addElement( grille_p.getQuadIJ(0, i, 0) )
groupe_bas.addElement( grille_g.getQuadIJ(0, i, 0) )
groupe_haut.addElement( grille_p.getQuadIJ(0, i, 1) )
groupe_haut.addElement( grille_g.getQuadIJ(0, i, 1) )
for i in xrange(3):
h = prisme.getHexa(i)
groupe_bas.addElement( h.getQuad(2) )
groupe_haut.addElement( h.getQuad(3) )
# -------------------------- Define border group
for i in xrange(2):
groupe_contour.addElement( grille_p.getQuadJK(1, i, 0) )
for i in [0, 2]:
groupe_contour.addElement( grille_g.getQuadJK(1, i, 0) )
for i in xrange(3):
h = prisme.getHexa(i)
groupe_contour.addElement( h.getQuad(4) )
groupe_contour.addElement( h.getQuad(5) )
# -------------------------- Define 3 groups of volumes
groupe_petit = doc.addHexaGroup("Petit")
groupe_grand = doc.addHexaGroup("Grand")
groupe_prisme = doc.addHexaGroup("Prisme")
for i in xrange(3):
groupe_petit.addElement( grille_p.getHexa(i) )
groupe_grand.addElement( grille_g.getHexa(i) )
for i in xrange(3):
groupe_prisme.addElement( prisme.getHexa(i) )
Go back to Steps
Mesh generation¶
blocs = hexablock.mesh(doc)
## .. and show statistics
muv, mue, muq, muh = hexablock.dump(doc, blocs)