def test_accounts_for_offset_centre_of_mass_in_applied_force(self):
# check applied force due to gravity is correct
b = RigidBody("body", mass=5.6, Xc=[1.2, 3.4, 5.4])
s = System(gravity=9.81) # need a System to define gravity
s.add_leaf(b)
s.setup()
b.calc_mass()
b.calc_external_loading()
assert_array_equal(b.applied_forces, b.mass * 9.81 * array([0, 0, -1, -3.4, 1.2, 0]))
def test_accounts_for_offset_centre_of_mass_in_applied_force(self):
# check applied force due to gravity is correct
b = RigidBody('body', mass=5.6, Xc=[1.2, 3.4, 5.4])
s = System(gravity=9.81) # need a System to define gravity
s.add_leaf(b)
s.setup()
b.calc_mass()
b.calc_external_loading()
assert_array_equal(b.applied_forces,
b.mass * 9.81 * array([0, 0, -1, -3.4, 1.2, 0]))
def test_interal_forces(self):
# NB minus sign because convention for applied_stress is that
# stiffness loads are positive.
b = RigidBody('body', 1)
# Constant loading
b.nodal_load = np.array([2, 3.1, 2.1])
b.calc_external_loading()
assert_array_equal(b.applied_forces, [2, 3.1, 2.1, 0, 0, 0])
assert_array_equal(b.applied_stress, [])
# Loading function
b.nodal_load = lambda element, t: np.ones(3)
b.calc_external_loading()
assert_array_equal(b.applied_forces, [1, 1, 1, 0, 0, 0])
assert_array_equal(b.applied_stress, [])
def test_interal_forces(self):
# NB minus sign because convention for applied_stress is that
# stiffness loads are positive.
b = RigidBody("body", 1)
# Constant loading
b.nodal_load = np.array([2, 3.1, 2.1])
b.calc_external_loading()
assert_array_equal(b.applied_forces, [2, 3.1, 2.1, 0, 0, 0])
assert_array_equal(b.applied_stress, [])
# Loading function
b.nodal_load = lambda element, t: np.ones(3)
b.calc_external_loading()
assert_array_equal(b.applied_forces, [1, 1, 1, 0, 0, 0])
assert_array_equal(b.applied_stress, [])
