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
a QuadForest from the mesh. The forest is populated with quadtrees 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:
QuadForest: Initial forest for topology optimization
"""
# Load the geometry model
geo = TMR.LoadModel('biclamped_traction.stp')
# Mark the boundary condition faces
verts = geo.getVertices()
edges = geo.getEdges()
faces = geo.getFaces()
edges[1].setName('fixed')
edges[9].setName('fixed')
edges[4].setName('traction')
# Create the mesh
mesh = TMR.Mesh(comm, geo)
# Set the meshing options
opts = TMR.MeshOptions()
# Create the surface mesh
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)
# Create the quad forest and set the topology of the forest
forest = TMR.QuadForest(comm)
forest.setTopology(topo)
# Set parameters for later usage
forest.createTrees(depth)
return forest
opts.num_smoothing_steps = 20
opts.write_mesh_quality_histogram = 1
# Mesh the geometry with the given target size
htarget = 10.0
mesh.mesh(htarget, opts=opts)
mesh.writeToVTK('surface-mesh.vtk')
# 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.QuadForest(comm)
forest.setTopology(topo)
# Make the creator class
bcs = TMR.BoundaryConditions()
bcs.addBoundaryCondition('x+')
bcs.addBoundaryCondition('x-')
bcs.addBoundaryCondition('y+')
bcs.addBoundaryCondition('y-')
# Allocate the creator class
creator = CreateMe(bcs)
# Create the initial forest
nlevels = 2
forest.createTrees(nlevels - 1)
def create_mesh(n, AR, prob, ratio1, ratio2, forced_portion, MBB_bc_portion,
force_magnitude, use_concentrated_force, use_hole, hole_radius):
Ly = 1.0
Lx = Ly*AR
# Create tmr geometry object
geo = create_geo(AR, prob, forced_portion, MBB_bc_portion,
ratio1, ratio2, use_hole, hole_radius)
# Create the mesh
comm = MPI.COMM_WORLD
mesh = TMR.Mesh(comm, geo)
# Mesh the part
opts = TMR.MeshOptions()
opts.frontal_quality_factor = 1.25
opts.num_smoothing_steps = 20
opts.write_mesh_quality_histogram = 1
# Mesh the geometry with the given target size
htarget = Ly / n
mesh.mesh(htarget, opts=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.QuadForest(comm)
forest.setTopology(topo)
# Create random trees and balance the mesh. Print the output file
forest.createTrees()
forest.balance(1)
# Create the nodes
forest.createNodes()
# Get the mesh connectivity
conn = forest.getMeshConn()
# Get the node locations
X = forest.getPoints()
# Set the nodal positions using only the x and y locations
X = np.array(X[:,:2])
# Get the nodes with the specified name
if prob == 'cantilever':
bcs = forest.getNodesWithName('5')
elif prob == 'MBB':
bc1 = forest.getNodesWithName('6')
bc2 = forest.getNodesWithName('2')
elif prob == 'michell':
bcs = forest.getNodesWithName('6')
elif prob == 'lbracket':
bcs = forest.getNodesWithName('6')
# Create the vars array with the number of nodes
nnodes = np.max(conn)+1
dof = np.zeros((nnodes, 2), dtype=int)
# Set the vars to a negative index where we have a constraint
if prob == 'MBB':
# If it is MBB problem, we only fix x degree of freedom at left edge
dof[bc1, 0] = -1
dof[bc2, 1] = -1
else:
dof[bcs, :] = -1
# Assign variables to the nodes
ndof = 0
for i in range(nnodes):
if dof[i,0] >= 0:
dof[i,0] = ndof
ndof += 1
if dof[i,1] >= 0:
dof[i,1] = ndof
ndof += 1
# Set up the force vector
force = np.zeros(ndof)
# Assign the force vector
if prob == 'cantilever':
if use_concentrated_force:
south_east_corner_node = -1
xpos = X[0, 0]
ypos = X[0, 0]
for i in range(nnodes):
if X[i, 0] >= xpos and X[i, 1] <= ypos:
south_east_corner_node = i
xpos = X[i, 0]
ypos = X[i, 1]
force[dof[south_east_corner_node, 1]] = -force_magnitude
else:
quads_on_edge = forest.getQuadsWithName('2')
for q in quads_on_edge:
if q.info < 2:
n1 = q.info
n2 = q.info + 2
else:
n1 = q.info//2
n2 = n1 + 1
v1 = dof[conn[q.face, n1], 1]
v2 = dof[conn[q.face, n2], 1]
force[v1] = -force_magnitude
force[v2] = -force_magnitude
force[:] /= np.count_nonzero(force)
elif prob == 'michell':
if use_concentrated_force:
distance = Lx**2 + Ly**2
xtarget = Lx
ytarget = Ly / 2
middle_node = -1
for i in range(nnodes):
xpos = X[i, 0]
ypos = X[i, 1]
if (xpos-xtarget)**2 + (ypos-ytarget)**2 <= distance:
middle_node = i
distance = (xpos-xtarget)**2 + (ypos-ytarget)**2
force[dof[middle_node, 1]] = -force_magnitude
else:
quads_on_edge = forest.getQuadsWithName('3')
for q in quads_on_edge:
if q.info < 2:
n1 = q.info
n2 = q.info + 2
else:
n1 = q.info//2
n2 = n1 + 1
v1 = dof[conn[q.face, n1], 1]
v2 = dof[conn[q.face, n2], 1]
force[v1] = -force_magnitude
force[v2] = -force_magnitude
force[:] /= np.count_nonzero(force)
elif prob == 'MBB':
if use_concentrated_force:
distance = Lx**2 + Ly**2
xtarget = 0
ytarget = Ly
north_west_node = -1
for i in range(nnodes):
xpos = X[i, 0]
ypos = X[i, 1]
if (xpos-xtarget)**2 + (ypos-ytarget)**2 <= distance:
north_west_node = i
distance = (xpos-xtarget)**2 + (ypos-ytarget)**2
force[dof[north_west_node, 1]] = -force_magnitude
else:
quads_on_edge = forest.getQuadsWithName('5')
for q in quads_on_edge:
if q.info < 2:
n1 = q.info
n2 = q.info + 2
else:
n1 = q.info//2
n2 = n1 + 1
v1 = dof[conn[q.face, n1], 1]
v2 = dof[conn[q.face, n2], 1]
force[v1] = -force_magnitude
force[v2] = -force_magnitude
force[:] /= np.count_nonzero(force)
elif prob == 'lbracket':
if use_concentrated_force:
distance = Lx**2 + Ly**2
xtarget = Lx
ytarget = Ly*ratio2
middle_node = -1
for i in range(nnodes):
xpos = X[i, 0]
ypos = X[i, 1]
if (xpos-xtarget)**2 + (ypos-ytarget)**2 <= distance:
middle_node = i
distance = (xpos-xtarget)**2 + (ypos-ytarget)**2
force[dof[middle_node, 1]] = -force_magnitude
else:
quads_on_edge = forest.getQuadsWithName('3')
for q in quads_on_edge:
if q.info < 2:
n1 = q.info
n2 = q.info + 2
else:
n1 = q.info//2
n2 = n1 + 1
v1 = dof[conn[q.face, n1], 1]
v2 = dof[conn[q.face, n2], 1]
force[v1] = -force_magnitude
force[v2] = -force_magnitude
force[:] /= np.count_nonzero(force)
nelems = len(conn)
return nelems, nnodes, ndof, conn, X, dof, force
def create_forest(comm, depth, htarget):
'''
Load the 3D step file and convert it to a 2D model
'''
geo = TMR.LoadModel('battery_3d.step')
verts = []
edges = []
faces = []
all_faces = geo.getFaces()
# Select only the facs on one face
faces.append(all_faces[3]) # The structure's face
faces.extend(all_faces[(len(all_faces) -
9):len(all_faces)]) # The face of the 9 batteries
# Add only the verts and edges associated with the faces that we selected
vert_ids = []
edge_ids = []
for f in faces:
num_loops = f.getNumEdgeLoops()
for i in range(num_loops):
el = f.getEdgeLoop(i)
edge_list, _ = el.getEdgeLoop()
for e in edge_list:
if e.getEntityId() not in edge_ids:
edges.append(e)
edge_ids.append(e.getEntityId())
v1, v2 = e.getVertices()
if v1.getEntityId() not in vert_ids:
verts.append(v1)
vert_ids.append(v1.getEntityId())
if v2.getEntityId() not in vert_ids:
verts.append(v2)
vert_ids.append(v2.getEntityId())
# Create the new 2D geometry model
geo = TMR.Model(verts, edges, faces)
# Name the faces that we need to use
faces[7].setName('battery_0') # Corner battery face
faces[8].setName('battery_1') # Adjacent battery
faces[1].setName('battery_2') # Diagonal battery
faces[2].setName('battery') # All the other batteries
faces[3].setName('battery')
faces[4].setName('battery')
faces[5].setName('battery')
faces[6].setName('battery')
faces[9].setName('battery')
faces[0].setName('aluminum')
# Create the mesh object
mesh = TMR.Mesh(comm, geo)
# Mesh the part
opts = TMR.MeshOptions()
opts.write_mesh_quality_histogram = 1
# Mesh the geometry with the given target size
mesh.mesh(htarget, opts=opts)
# mesh.writeToVTK('battery_mesh.vtk')
# 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.QuadForest(comm)
forest.setTopology(topo)
forest.createTrees(depth)
return forest
