Animation of dynamic analysis and mode shapes of a 2d Portal Frame
Example .py
file can be downloaded here
:
If you do not see the animation running, depending on Python environment, you will have to set a matplotlib backand which supports animation.
For example to see the matplotlib animations in the Spyder Python
editor (which should be installed with the Anaconda platform), in the
IPython console run %matplotlib qt
. Then comment/uncomment one of
the two animations.
1import openseespy.opensees as ops
2import opsvis as opsv
3
4import numpy as np
5import matplotlib.pyplot as plt
6
7# input_parameters = (3.8, 50., 100.)
8# input_parameters = (53.5767, 50., 100.)
9input_parameters = (20.8, 300., 8.)
10# input_parameters = (70.0, 500., 2.)
11
12pf, sfac_a, tkt = input_parameters
13
14ops.wipe()
15ops.model('basic', '-ndm', 2, '-ndf', 3) # frame 2D
16
17colL, girL = 4., 6.
18
19Acol, Agir = 0.06, 0.06
20IzCol, IzGir = 0.0002, 0.0002
21
22E = 3.2e10
23rho = 2400.
24muCol = rho * Acol
25muGir = rho * Agir
26massCol = ['-mass', muCol, '-cMass']
27massGir = ['-mass', muGir, '-cMass']
28
29ops.node(0, 0.0, 0.0)
30ops.node(1, 0.0, 2.0)
31ops.node(2, 0.0, 4.0)
32ops.node(3, 3.0, 4.0)
33ops.node(4, 6.0, 4.0)
34ops.node(5, 6.0, 2.0)
35ops.node(6, 6.0, 0.0)
36
37ops.fix(0, 1, 1, 1)
38ops.fix(6, 1, 1, 0)
39
40gTTag = 1
41ops.geomTransf('Linear', gTTag)
42
43# 1st column
44ops.element('elasticBeamColumn', 1, 0, 1, Acol, E, IzCol, gTTag, *massCol)
45ops.element('elasticBeamColumn', 2, 1, 2, Acol, E, IzCol, gTTag, *massCol)
46# girder
47ops.element('elasticBeamColumn', 3, 2, 3, Agir, E, IzGir, gTTag, *massGir)
48ops.element('elasticBeamColumn', 4, 3, 4, Agir, E, IzGir, gTTag, *massGir)
49# 2nd column
50ops.element('elasticBeamColumn', 5, 4, 5, Acol, E, IzCol, gTTag, *massCol)
51ops.element('elasticBeamColumn', 6, 5, 6, Acol, E, IzCol, gTTag, *massCol)
52
53t0 = 0.
54tk = 1.
55Tp = 1/pf
56P0 = 15000.
57dt = 0.002
58n_steps = int((tk-t0)/dt)
59
60tsTag = 1
61ops.timeSeries('Trig', tsTag, t0, tk, Tp, '-factor', P0)
62
63patTag = 1
64ops.pattern('Plain', patTag, tsTag)
65ops.load(1, 1., 0., 0.)
66
67ops.constraints('Transformation')
68ops.numberer('RCM')
69ops.test('NormDispIncr', 1.0e-6, 10, 1)
70ops.algorithm('Linear')
71ops.system('ProfileSPD')
72ops.integrator('Newmark', 0.5, 0.25)
73ops.analysis('Transient')
74
75el_tags = ops.getEleTags()
76
77nels = len(el_tags)
78
79Eds = np.zeros((n_steps, nels, 6))
80timeV = np.zeros(n_steps)
81
82# transient analysis loop and collecting the data
83for step in range(n_steps):
84 ops.analyze(1, dt)
85 timeV[step] = ops.getTime()
86 # collect disp for element nodes
87 for el_i, ele_tag in enumerate(el_tags):
88 nd1, nd2 = ops.eleNodes(ele_tag)
89 Eds[step, el_i, :] = [ops.nodeDisp(nd1)[0],
90 ops.nodeDisp(nd1)[1],
91 ops.nodeDisp(nd1)[2],
92 ops.nodeDisp(nd2)[0],
93 ops.nodeDisp(nd2)[1],
94 ops.nodeDisp(nd2)[2]]
95
96fmt_defo = {'color': 'blue', 'linestyle': 'solid', 'linewidth': 3.0,
97 'marker': '', 'markersize': 6}
98
99# 1. animate the deformated shape
100anim = opsv.anim_defo(Eds, timeV, sfac_a, fmt_defo=fmt_defo,
101 xlim=[-1, 7], ylim=[-1, 5], fig_wi_he=(30., 22.))
102
103plt.show()
104
105# 2. after closing the window, animate the specified mode shape
106eigVals = ops.eigen(5)
107
108modeNo = 2 # specify which mode to animate
109f_modeNo = np.sqrt(eigVals[modeNo-1])/(2*np.pi) # i-th natural frequency
110
111anim = opsv.anim_mode(modeNo, fmt_defo=fmt_defo,
112 xlim=[-1, 7], ylim=[-1, 5], fig_wi_he=(30., 22.))
113plt.title(f'Mode {modeNo}, f_{modeNo}: {f_modeNo:.3f} Hz')
114
115plt.show()