def test_recorder_time_step_can_handle_fp_precision():
import tempfile
opy.model('basic', '-ndm', 2, '-ndf', 3)
opy.node(1, 0.0, 0.0)
opy.node(2, 0.0, 5.0)
opy.fix(2, 0, 1, 0)
opy.fix(1, 1, 1, 1)
opy.equalDOF(2, 1, 2)
opy.mass(2, 1.0, 0.0, 0.0)
opy.geomTransf('Linear', 1, '-jntOffset')
opy.element('elasticBeamColumn', 1, 1, 2, 1.0, 1e+06, 0.00164493, 1)
opy.timeSeries('Path', 1, '-dt', 0.1, '-values', 0.0, -0.001, 0.001,
-0.015, 0.033, 0.105, 0.18)
opy.pattern('UniformExcitation', 1, 1, '-accel', 1)
opy.rayleigh(0.0, 0.0159155, 0.0, 0.0)
opy.wipeAnalysis()
opy.algorithm('Newton')
opy.system('SparseSYM')
opy.numberer('RCM')
opy.constraints('Transformation')
opy.integrator('Newmark', 0.5, 0.25)
opy.analysis('Transient')
opy.test('EnergyIncr', 1e-07, 10, 0, 2)
node_rec_ffp = tempfile.NamedTemporaryFile(delete=False).name
ele_rec_ffp = tempfile.NamedTemporaryFile(delete=False).name
rdt = 0.01
adt = 0.001
opy.recorder('Node', '-file', node_rec_ffp, '-precision', 16, '-dT', rdt,
'-rTolDt', 0.00001, '-time', '-node', 1, '-dof', 1, 'accel')
opy.recorder('Element', '-file', ele_rec_ffp, '-precision', 16, '-dT', rdt,
'-rTolDt', 0.00001, '-time', '-ele', 1, 'force')
opy.record()
for i in range(1100):
opy.analyze(1, adt)
opy.getTime()
opy.wipe()
a = open(node_rec_ffp).read().splitlines()
for i in range(len(a) - 1):
dt = float(a[i + 1].split()[0]) - float(a[i].split()[0])
assert abs(dt - 0.01) < adt * 0.1, (i, dt)
a = open(ele_rec_ffp).read().splitlines()
for i in range(len(a) - 1):
dt = float(a[i + 1].split()[0]) - float(a[i].split()[0])
assert abs(dt - 0.01) < adt * 0.1, (i, dt)
op.constraints('Penalty', 1.0E16, 1.0E16)
op.test('NormDispIncr', 1e-3, 35, 1)
op.algorithm('KrylovNewton')
op.numberer('RCM')
op.system('ProfileSPD')
op.integrator('Newmark', gamma, beta)
op.rayleigh(a0, a1, 0.0, 0.0)
op.analysis('Transient')
# perform analysis with timestep reduction loop
ok = op.analyze(nSteps, dT)
# if analysis fails, reduce timestep and continue with analysis
if ok != 0:
print("did not converge, reducing time step")
curTime = op.getTime()
mTime = curTime
print("curTime: ", curTime)
curStep = curTime / dT
print("curStep: ", curStep)
rStep = (nSteps - curStep) * 2.0
remStep = np.int((nSteps - curStep) * 2.0)
print("remStep: ", remStep)
dT = dT / 2.0
print("dT: ", dT)
ok = op.analyze(remStep, dT)
# if analysis fails again, reduce timestep and continue with analysis
if ok != 0:
print("did not converge, reducing time step")
curTime = op.getTime()
def get_inelastic_response(mass,
k_spring,
f_yield,
motion,
dt,
xi=0.05,
r_post=0.0):
"""
Run seismic analysis of a nonlinear SDOF
:param mass: SDOF mass
:param k_spring: spring stiffness
:param f_yield: yield strength
:param motion: list, acceleration values
:param dt: float, time step of acceleration values
:param xi: damping ratio
:param r_post: post-yield stiffness
:return:
"""
op.wipe()
op.model('basic', '-ndm', 2, '-ndf', 3) # 2 dimensions, 3 dof per node
# Establish nodes
bot_node = 1
top_node = 2
op.node(bot_node, 0., 0.)
op.node(top_node, 0., 0.)
# Fix bottom node
op.fix(top_node, opc.FREE, opc.FIXED, opc.FIXED)
op.fix(bot_node, opc.FIXED, opc.FIXED, opc.FIXED)
# Set out-of-plane DOFs to be slaved
op.equalDOF(1, 2, *[2, 3])
# nodal mass (weight / g):
op.mass(top_node, mass, 0., 0.)
# Define material
bilinear_mat_tag = 1
mat_type = "Steel01"
mat_props = [f_yield, k_spring, r_post]
op.uniaxialMaterial(mat_type, bilinear_mat_tag, *mat_props)
# Assign zero length element
beam_tag = 1
op.element('zeroLength', beam_tag, bot_node, top_node, "-mat",
bilinear_mat_tag, "-dir", 1, '-doRayleigh', 1)
# Define the dynamic analysis
load_tag_dynamic = 1
pattern_tag_dynamic = 1
values = list(-1 * motion) # should be negative
op.timeSeries('Path', load_tag_dynamic, '-dt', dt, '-values', *values)
op.pattern('UniformExcitation', pattern_tag_dynamic, opc.X, '-accel',
load_tag_dynamic)
# set damping based on first eigen mode
angular_freq = op.eigen('-fullGenLapack', 1)**0.5
alpha_m = 0.0
beta_k = 2 * xi / angular_freq
beta_k_comm = 0.0
beta_k_init = 0.0
op.rayleigh(alpha_m, beta_k, beta_k_init, beta_k_comm)
# Run the dynamic analysis
op.wipeAnalysis()
op.algorithm('Newton')
op.system('SparseGeneral')
op.numberer('RCM')
op.constraints('Transformation')
op.integrator('Newmark', 0.5, 0.25)
op.analysis('Transient')
tol = 1.0e-10
iterations = 10
op.test('EnergyIncr', tol, iterations, 0, 2)
analysis_time = (len(values) - 1) * dt
analysis_dt = 0.001
outputs = {
"time": [],
"rel_disp": [],
"rel_accel": [],
"rel_vel": [],
"force": []
}
while op.getTime() < analysis_time:
curr_time = op.getTime()
op.analyze(1, analysis_dt)
outputs["time"].append(curr_time)
outputs["rel_disp"].append(op.nodeDisp(top_node, 1))
outputs["rel_vel"].append(op.nodeVel(top_node, 1))
outputs["rel_accel"].append(op.nodeAccel(top_node, 1))
op.reactions()
outputs["force"].append(
-op.nodeReaction(bot_node, 1)) # Negative since diff node
op.wipe()
for item in outputs:
outputs[item] = np.array(outputs[item])
return outputs
ops.fix(1, 1)
ops.element('Truss', 1, 1, 2, 10.0, 1)
ops.timeSeries('Linear', 1)
ops.pattern('Plain', 1, 1)
ops.load(2, 100.0)
ops.constraints('Transformation')
ops.numberer('ParallelPlain')
ops.test('NormDispIncr', 1e-6, 6, 2)
ops.system('ProfileSPD')
ops.integrator('Newmark', 0.5, 0.25)
# ops.analysis('Transient')
ops.algorithm('Linear')
ops.analysis('VariableTransient')
ops.analyze(5, 0.0001, 0.00001, 0.001, 10)
time = ops.getTime()
print(f'time: ', ops.getTime())
approx_vtime = 0.0001 + 0.001 # One step at target, then one step at maximum
assert 0.99 < time / approx_vtime < 1.01, (time, approx_vtime)
ops.setTime(0.0)
# Can still run a non-variable analysis - since analyze function has multiple dispatch.
ops.analyze(5, 0.0001)
time = ops.getTime()
print(f'time: ', ops.getTime())
approx_vtime = 0.0001 * 5 # variable transient is not active so time should be dt * 5
# If variable transient is not active then time would be 0.0005
assert 0.99 < time / approx_vtime < 1.01, (time, approx_vtime)
# ------------------------------
# Finally perform the analysis
# ------------------------------
# record once at time 0
ops.record()
# Perform an eigenvalue analysis
lam = ops.eigen(2)
Tstart = 2.0*math.pi/math.sqrt(lam[0])
print("Fundamental period at start of transient analysis: ", Tstart, "sec\n")
# set some variables
tFinal = 2000 * 0.01
tCurrent = ops.getTime()
ok = 0
# Perform the transient analysis
while ((ok == 0) and (tCurrent < tFinal)):
ok = ops.analyze(1, 0.01)
# if the analysis fails try initial tangent iteration
if (ok != 0):
print("regular newton failed .. lets try an initial stiffness for this step")
ops.test("NormDispIncr", 1.0E-12, 100, 0)
ops.algorithm("ModifiedNewton", "-initial")
ok = ops.analyze(1, 0.01)
if (ok == 0):
print("that worked .. back to regular newton")
def test_recorder_time_step_is_stable():
opy.model('basic', '-ndm', 2, '-ndf', 2)
opy.loadConst('-time', 1e+13)
opy.node(1, 0.0, 0.0)
opy.node(2, 0.5, 0.0)
opy.node(3, 0.0, -0.5)
opy.node(4, 0.5, -0.5)
opy.equalDOF(3, 4, 1, 2)
opy.node(5, 0.0, -1.0)
opy.node(6, 0.5, -1.0)
opy.equalDOF(5, 6, 1, 2)
opy.node(7, 0.0, -1.5)
opy.node(8, 0.5, -1.5)
opy.equalDOF(7, 8, 1, 2)
opy.node(9, 0.0, -2.0)
opy.node(10, 0.5, -2.0)
opy.equalDOF(9, 10, 1, 2)
opy.node(11, 0.0, -2.5)
opy.node(12, 0.5, -2.5)
opy.equalDOF(11, 12, 1, 2)
opy.node(13, 0.0, -3.0)
opy.node(14, 0.5, -3.0)
opy.equalDOF(13, 14, 1, 2)
opy.fix(13, 0, 1)
opy.fix(14, 0, 1)
opy.node(15, 0.0, -3.0)
opy.node(16, 0.0, -3.0)
opy.fix(15, 1, 1)
opy.fix(16, 0, 1)
opy.equalDOF(13, 14, 1)
opy.equalDOF(13, 16, 1)
opy.nDMaterial('ElasticIsotropic', 1, 212500.0, 0.0, 1.7)
opy.element('SSPquad', 1, 3, 4, 2, 1, 1, 'PlaneStrain', 1.0, 0.0, 16.677)
opy.element('SSPquad', 2, 5, 6, 4, 3, 1, 'PlaneStrain', 1.0, 0.0, 16.677)
opy.element('SSPquad', 3, 7, 8, 6, 5, 1, 'PlaneStrain', 1.0, 0.0, 16.677)
opy.element('SSPquad', 4, 9, 10, 8, 7, 1, 'PlaneStrain', 1.0, 0.0, 16.677)
opy.element('SSPquad', 5, 11, 12, 10, 9, 1, 'PlaneStrain', 1.0, 0.0,
16.677)
opy.element('SSPquad', 6, 13, 14, 12, 11, 1, 'PlaneStrain', 1.0, 0.0,
16.677)
opy.uniaxialMaterial('Viscous', 2, 212.5, 1.0)
opy.element('zeroLength', 7, 15, 16, '-mat', 2, '-dir', 1)
opy.constraints('Transformation')
opy.test('NormDispIncr', 0.0001, 30, 0, 2)
opy.algorithm('Newton', False, False, False)
opy.numberer('RCM')
opy.system('ProfileSPD')
opy.integrator('Newmark', 0.5, 0.25)
opy.analysis('Transient')
opy.analyze(40, 1.0)
opy.analyze(50, 0.5)
opy.setTime(1.0e3)
opy.wipeAnalysis()
opy.recorder('Node', '-file', 'time_0_01.txt', '-precision', 16, '-dT',
0.01, '-rTolDt', 0.00001, '-time', '-node', 1, '-dof', 1,
'accel')
opy.recorder('Element', '-file', 'etime_0_01.txt', '-precision', 16, '-dT',
0.01, '-rTolDt', 0.00001, '-time', '-ele', 1, 2, 'stress')
opy.recorder('EnvelopeNode', '-file', 'entime_0_01.txt', '-precision', 16,
'-dT', 0.01, '-time', '-node', 1, '-dof', 1, 'accel')
# opy.recorder('Drift', '-file', 'dtime_0_01.txt', '-precision', 16, '-dT', 0.01, '-time',
# '-iNode', 1, '-jNode', 2, '-dof', 1, '-perpDirn', 2)
opy.timeSeries('Path', 1, '-dt', 0.01, '-values', -0.0, -0.0, -0.0, -0.0,
-0.0, -0.0, -0.0, -0.0, -7.51325e-05)
opy.pattern('Plain', 1, 1)
opy.load(13, 1.0, 0.0)
opy.algorithm('Newton', False, False, False)
opy.system('SparseGeneral')
opy.numberer('RCM')
opy.constraints('Transformation')
opy.integrator('Newmark', 0.5, 0.25)
opy.rayleigh(0.17952, 0.000909457, 0.0, 0.0)
opy.analysis('Transient')
opy.test('EnergyIncr', 1e-07, 10, 0, 2)
opy.record()
opy.analyze(1, 0.001)
for i in range(1100):
print(i)
opy.analyze(1, 0.001)
cur_time = opy.getTime()
opy.wipe()
a = open('time_0_01.txt').read().splitlines()
for i in range(len(a) - 1):
dt = float(a[i + 1].split()[0]) - float(a[i].split()[0])
assert abs(dt - 0.01) < 0.0001, (i, dt)