def setup(self):
# Define a mode shape with deflection x^2 in the y direction
self.x = x = arange(0, 10.1, 1)
self.L = self.x[-1]
zero = 0 * x
shapes = c_[zero, x**2, zero].reshape((len(x), 3, 1))
rotations = c_[zero, 2 * x, zero].reshape((len(x), 3, 1))
self.modes = ModalRepresentation(x,
freqs=[1],
shapes=shapes,
rotations=rotations)
def setup(self):
x = linspace(0, self.length, 50)
density = self.mass / self.length
# One mode shape: linear in z direction.
shape = linspace(0, 1, 50)
rotation = -np.ones(50) / self.length
shapes = c_[0 * x, 0 * x, shape].reshape((len(x), 3, 1))
rotations = c_[0 * x, rotation, 0 * x].reshape((len(x), 3, 1))
# Natural frequency: w^2 = k/I
I0 = self.mass * (self.length**2 / 3) # inertia about end
freq = (self.stiffness / I0)**0.5
modes = ModalRepresentation(x, density, shapes, rotations, [freq])
self.beam = ModalElement('beam', modes)
def make_a_modal_beam(length, density=None, section_inertia=None):
x = linspace(0, length, 10)
modes = ModalRepresentation(x, density, section_inertia=section_inertia)
beam = ModalElement('beam', modes)
return beam
def _mock_rigid_uniform_modes(density, length):
"""Return empty modal representation of 20m long rigid beam"""
x = arange(0, length + 0.01)
return ModalRepresentation(x, density * ones_like(x))
def setup(self):
self.x = arange(0, 10.1, 1)
self.L = self.x[-1]
self.modes = ModalRepresentation(self.x)