G2 Example 9

G2Example9.py

# ------------------------------------------------------------------------
# The following Python code is implemented by Professor Terje Haukaas at
# the University of British Columbia in Vancouver, Canada. It is made
# freely available online at terje.civil.ubc.ca together with notes,
# examples, and additional Python code. Please be cautious when using
# this code; it may contain bugs and comes without warranty of any kind.
# ------------------------------------------------------------------------
# Units: [N, mm]

from G2AnalysisNonlinearStatic import *
from G2Model import *

elementType = 3          # Truss element with geometric nonlinearity
L = 2000.0               # Length of each element
F = 1500.0               # Vertical load on the truss
N0 = 0.0                 # Initial axial force
h = 50.0                 # Truss camber
A = 25**2                # Cross-section area
E = 210000.0             # Young's modulus
nsteps = 20              # Number of load steps
dt = 1.0/nsteps          # Steps of pseudo-time
maxIter = 100            # Maximum number of equilibrium iterations
KcalcFrequency = 1       # 0=initial stress method, 1=Newton-Raphson, maxIter=Modified NR
tol = 1e-3               # Convergence tolerance
trackNode = 2            # Node to be plotted
trackDOF = 2             # DOF to be plotted

# Nodes
NODES = np.array([[0.0, 0.0],
                  [L,   h],
                  [2*L, 0.0]])

# Boundary conditions
CONSTRAINTS = np.array([[1, 1],
                        [0, 0],
                        [1, 1]])

# Elements
ELEMENTS = [[elementType, E, A, N0, 1, 2],
            [elementType, E, A, N0, 2, 3]]

# Empty arrays
SECTIONS = np.zeros((2,2))
MATERIALS = np.zeros((2,2))

# Loads
LOADS = np.array([[0.0, 0.0],
                  [0.0, -F],
                  [0.0, 0.0]])

# Loads
MASS = np.array([[0.0, 0.0],
                 [0.0, 0.0],
                 [0.0, 0.0]])

# Create the model object
a = [NODES, CONSTRAINTS, ELEMENTS, SECTIONS, MATERIALS, LOADS, MASS]
m = model(a)

# Analyze
nonlinearStaticAnalysis(m, nsteps, dt, maxIter, KcalcFrequency, tol, trackNode, trackDOF, [])