def create_forest(comm, depth, htarget):
"""
Create an initial forest for analysis and optimization.
This code loads in the model, sets names, meshes the geometry and creates
an OctForest from the mesh. The forest is populated with octrees with
the specified depth.
Args:
comm (MPI_Comm): MPI communicator
depth (int): Depth of the initial trees
htarget (float): Target global element mesh size
Returns:
OctForest: Initial forest for topology optimization
"""
# Load the geometry model
geo = TMR.LoadModel('../cantilever/cantilever.stp')
# Mark the boundary condition faces
verts = geo.getVertices()
edges = geo.getEdges()
faces = geo.getFaces()
volumes = geo.getVolumes()
faces[3].setName('fixed')
faces[4].setSource(volumes[0], faces[5])
verts[4].setName('pt1')
verts[3].setName('pt2')
# Set the boundary conditions for the problem
bcs = TMR.BoundaryConditions()
bcs.addBoundaryCondition('fixed')
# Create the mesh
mesh = TMR.Mesh(comm, geo)
# Set the meshing options
opts = TMR.MeshOptions()
# Create the surface mesh
mesh.mesh(args.htarget, opts)
# Create a model from the mesh
model = mesh.createModelFromMesh()
# Create the corresponding mesh topology from the mesh-model
topo = TMR.Topology(comm, model)
# Create the quad forest and set the topology of the forest
forest = TMR.OctForest(comm)
forest.setTopology(topo)
# Create the trees
forest.createTrees(depth)
return forest
opts = TMR.MeshOptions() opts.frontal_quality_factor = 1.25 opts.num_smoothing_steps = 50 opts.triangularize_print_iter = 50000 opts.write_mesh_quality_histogram = 1 # Create the surface mesh mesh.mesh(0.02, opts) # Create a model from the mesh model = mesh.createModelFromMesh() # Create the corresponding mesh topology from the mesh-model topo = TMR.Topology(comm, model) # Create the quad forest and set the topology of the forest forest = TMR.OctForest(comm) forest.setTopology(topo) forest.createTrees(1) forest.createNodes() ar = computeAR(forest) min_ang = computeMinAngle(forest) fshape = computeShape(forest) # Wrtie the mesh quality to vtk writeQualityToVtk(forest, ar, min_ang, fshape,fname='quality-bracket.vtk') plotShapeHist(fshape, xmin=np.amin(fshape), fname='bracket_shape_hist.pdf') plotARHist(ar, fname='bracket_ar_hist.pdf', xmax=np.ceil(4.0*np.amax(ar))/4.0) plotMinAngHist(min_ang, fname='bracket_ang_hist.pdf', xmin=np.amin(min_ang)-1.0)
# Set the meshing options
opts = TMR.MeshOptions()
opts.frontal_quality_factor = 1.25
opts.num_smoothing_steps = 10
opts.write_mesh_quality_histogram = 0
# Create the surface mesh
htarget = 4.0
mesh.mesh(htarget, opts)
# Create a model from the mesh
model = mesh.createModelFromMesh()
# Create the corresponding mesh topology from the mesh-model
topo = TMR.Topology(comm, model)
fine = TMR.OctForest(comm)
fine.setTopology(topo)
else:
conn = np.array([[0, 1, 3, 4, 6, 7, 9, 10], [8, 11, 2, 5, 7, 10, 1, 4]],
dtype=np.intc)
fine = TMR.OctForest(comm)
fine.setConnectivity(conn)
# Create the fine mesh
fine.createTrees(0)
refine = np.zeros(len(fine.getOctants()), dtype=np.intc)
if comm.rank == 0:
refine[0] = 4
fine.refine(refine)
fine.balance(1)
fine.repartition()
def create_3d_unstruct_mesh(n, AR, prob, ratio1, ratio2, hole_r,
forced_portion, force_magnitude, MBB_bc_portion,
loaded_thickness, ly):
comm = MPI.COMM_WORLD
# Create the egads context
ctx = egads.context()
# dimensions
Lx = ly * AR
Ly = ly
h = ly
parts = []
if prob == 'lbracket':
# Create base
x0 = [0, 0, 0]
x1 = [Lx * ratio1, Ly * ratio2, h]
B0 = ctx.makeSolidBody(egads.BOX, rdata=[x0, x1])
parts.append(ctx.makeTopology(egads.MODEL, children=[B0]))
# Create arm 1
x0 = [0, Ly * ratio2, 0]
x1 = [Lx * ratio1, Ly * (1 - ratio2), h]
B1 = ctx.makeSolidBody(egads.BOX, rdata=[x0, x1])
parts.append(ctx.makeTopology(egads.MODEL, children=[B1]))
# Create arm 2
x0 = [Lx * ratio1, 0, 0]
x1 = [Lx * (1 - ratio1), Ly * ratio2, h]
B2 = ctx.makeSolidBody(egads.BOX, rdata=[x0, x1])
# Create the cylinder cutout
xc = Lx * (ratio1 + 1) * 0.5
yc = Ly * ratio2 * 0.5
x0 = [xc, yc, 0]
x1 = [xc, yc, h]
r = hole_r * Ly * ratio2
C1 = ctx.makeSolidBody(egads.CYLINDER, rdata=[x0, x1, r])
parts.append(B2.solidBoolean(C1, egads.SUBTRACTION))
else:
# Create the box
x0 = [0, 0, 0]
x1 = [Lx, Ly, h]
B1 = ctx.makeSolidBody(egads.BOX, rdata=[x0, x1])
# Create the cylinder cutout
xc = Lx / 2
yc = Ly / 2
x0 = [xc, yc, 0]
x1 = [xc, yc, h]
r = hole_r * Ly
C1 = ctx.makeSolidBody(egads.CYLINDER, rdata=[x0, x1, r])
# parts.append(ctx.makeTopology(egads.MODEL, children=[B1]))
parts.append(B1.solidBoolean(C1, egads.SUBTRACTION))
# Create all of the models
geos = []
for p in parts:
geos.append(TMR.ConvertEGADSModel(p))
# Create the full list of vertices, edges, faces and volumes
verts = []
edges = []
faces = []
vols = []
for geo in geos:
verts.extend(geo.getVertices())
edges.extend(geo.getEdges())
faces.extend(geo.getFaces())
vols.extend(geo.getVolumes())
# Set all of the matching faces
TMR.setMatchingFaces(geos)
# Create the geometry
geo = TMR.Model(verts, edges, faces, vols)
# Create the new mesh
mesh = TMR.Mesh(comm, geo)
# Set the meshing options
opts = TMR.MeshOptions()
# opts.mesh_type_default = TMR.UNSTRUCTURED
opts.write_mesh_quality_histogram = 1
opts.triangularize_print_iter = 50000
# Create the surface mesh
htarget = ly / n
mesh.mesh(htarget, opts)
# Write the surface mesh to a file
# mesh.writeToVTK('block.vtk', 'hex')
# Create the model from the unstructured volume mesh
model = mesh.createModelFromMesh()
# Create the corresponding mesh topology from the mesh-model
topo = TMR.Topology(comm, model)
# Create the quad forest and set the topology of the forest
forest = TMR.OctForest(comm)
forest.setTopology(topo)
forest.createTrees()
forest.balance(1)
# Create the nodes
forest.createNodes()
# Get the mesh connectivity
conn = forest.getMeshConn()
nnodes = np.max(conn) + 1
nelems = len(conn)
# Get the node locations
X = forest.getPoints()
# Set boundary conditions
dof = -np.ones((nnodes, 3), dtype=int)
geo_bc_tol = 1e-6
if prob == 'cantilever' or prob == 'michell':
bc_x_max = geo_bc_tol
bc_x_min = -geo_bc_tol
bc_y_max = Ly + geo_bc_tol
bc_y_min = -geo_bc_tol
bc_z_max = h + geo_bc_tol
bc_z_min = -geo_bc_tol
ndof = 0
for i in range(nnodes):
if (bc_x_min <= X[i, 0] <= bc_x_max
and bc_y_min <= X[i, 1] <= bc_y_max
and bc_z_min <= X[i, 2] <= bc_z_max):
# This is the bc node
pass
else:
dof[i, 0] = ndof
ndof += 1
dof[i, 1] = ndof
ndof += 1
dof[i, 2] = ndof
ndof += 1
elif prob == 'MBB':
bc1_x_max = geo_bc_tol
bc1_x_min = -geo_bc_tol
bc1_y_max = Ly + geo_bc_tol
bc1_y_min = -geo_bc_tol
bc1_z_max = h + geo_bc_tol
bc1_z_min = -geo_bc_tol
bc2_x_max = Lx + geo_bc_tol
bc2_x_min = Lx * (1 - MBB_bc_portion) - geo_bc_tol
bc2_y_max = geo_bc_tol + geo_bc_tol
bc2_y_min = -geo_bc_tol
bc2_z_max = h + geo_bc_tol
bc2_z_min = -geo_bc_tol
ndof = 0
for i in range(nnodes):
if (bc1_x_min <= X[i, 0] <= bc1_x_max
and bc1_y_min <= X[i, 1] <= bc1_y_max
and bc1_z_min <= X[i, 2] <= bc1_z_max):
# This is the bc node
dof[i, 1] = ndof
ndof += 1
elif (bc2_x_min <= X[i, 0] <= bc2_x_max
and bc2_y_min <= X[i, 1] <= bc2_y_max
and bc2_z_min <= X[i, 2] <= bc2_z_max):
# This is also bc node
dof[i, 0] = ndof
ndof += 1
else:
dof[i, 0] = ndof
ndof += 1
dof[i, 1] = ndof
ndof += 1
dof[i, 2] = ndof
ndof += 1
elif prob == 'lbracket':
bc_x_max = Lx * ratio1 + geo_bc_tol
bc_x_min = -geo_bc_tol
bc_y_max = Ly + geo_bc_tol
bc_y_min = Ly - geo_bc_tol
bc_z_max = h + geo_bc_tol
bc_z_min = -geo_bc_tol
ndof = 0
for i in range(nnodes):
if (bc_x_min <= X[i, 0] <= bc_x_max
and bc_y_min <= X[i, 1] <= bc_y_max
and bc_z_min <= X[i, 2] <= bc_z_max):
# This is the bc node
pass
else:
dof[i, 0] = ndof
ndof += 1
dof[i, 1] = ndof
ndof += 1
dof[i, 2] = ndof
ndof += 1
# Set loading
force = np.zeros(ndof)
geo_tol = 1e-6
if prob == 'cantilever':
load_x_max = Lx + geo_tol
load_x_min = Lx - geo_tol
load_y_max = Ly * forced_portion + geo_tol
load_y_min = -geo_tol
load_z_max = 0.5 * h * (1 + loaded_thickness)
load_z_min = 0.5 * h * (1 - loaded_thickness)
force_dir = 1
force_scal = -1.0
elif prob == 'MBB':
load_x_max = Lx * MBB_bc_portion + geo_tol
load_x_min = -geo_tol
load_y_max = Ly + geo_tol
load_y_min = Ly - geo_tol
load_z_max = 0.5 * h * (1 + loaded_thickness) + geo_tol
load_z_min = 0.5 * h * (1 - loaded_thickness) - geo_tol
force_dir = 1
force_scal = -1.0
elif prob == 'michell':
load_x_max = Lx + geo_tol
load_x_min = Lx - geo_tol
load_y_max = 0.5 * Ly * (1 + forced_portion) + geo_tol
load_y_min = 0.5 * Ly * (1 - forced_portion) - geo_tol
load_z_max = 0.5 * h * (1 + loaded_thickness) + geo_tol
load_z_min = 0.5 * h * (1 - loaded_thickness) - geo_tol
force_dir = 1
force_scal = -1.0
elif prob == 'lbracket':
load_x_max = Lx + geo_tol
load_x_min = Lx - geo_tol
load_y_max = Ly * ratio2 + geo_tol
load_y_min = Ly * ratio2 * (1 - forced_portion) - geo_tol
load_z_max = 0.5 * h * (1 + loaded_thickness) + geo_tol
load_z_min = 0.5 * h * (1 - loaded_thickness) - geo_tol
force_dir = 1
force_scal = -1.0
nforce = 0
for i in range(nnodes):
if (load_x_min <= X[i, 0] <= load_x_max
and load_y_min <= X[i, 1] <= load_y_max
and load_z_min <= X[i, 2] <= load_z_max):
force[dof[i, force_dir]] = force_scal * force_magnitude
nforce += 1
force /= nforce
# for n in range(X.shape[0]):
# print('node:{:4d} x:{:6f} y:{:6f} z:{:6f}'.format(n, X[n, 0], X[n, 1], X[n, 2]))
# for ne in range(conn.shape[0]):
# print('elem:{:4d} conn = [{:3d} {:3d} {:3d} {:3d}]'.format(ne, conn[ne,0], conn[ne,1], conn[ne,2], conn[ne,3]))
return nelems, nnodes, ndof, conn, X, dof, force
