Plot stress distribution of a plane stress quad model

Example .py file can be downloaded here:

_images/quads_4x4_model.png _images/quads_4x4_defo.png _images/quads_4x4_sxx.png _images/quads_4x4_syy.png _images/quads_4x4_sxy.png _images/quads_4x4_vmis.png
  1import openseespy.opensees as ops
  2import opsvis as opsv
  3
  4import matplotlib.pyplot as plt
  5
  6ops.wipe()
  7ops.model('basic', '-ndm', 2, '-ndf', 2)
  8ops.node(1, 0., 0.)
  9ops.node(2, 0., 1.)
 10ops.node(3, 0., 2.)
 11ops.node(4, 0., 3.)
 12ops.node(5, 0., 4.)
 13ops.node(6, 1., 0.)
 14ops.node(7, 1., 1.)
 15ops.node(8, 1., 2.)
 16ops.node(9, 1., 3.)
 17ops.node(10, 1., 4.)
 18ops.node(11, 2., 0.)
 19ops.node(12, 2., 1.)
 20ops.node(13, 2., 2.)
 21ops.node(14, 2., 3.)
 22ops.node(15, 2., 4.)
 23ops.node(16, 3., 0.)
 24ops.node(17, 3., 1.)
 25ops.node(18, 3., 2.)
 26ops.node(19, 3., 3.)
 27ops.node(20, 3., 4.)
 28ops.node(21, 4., 0.)
 29ops.node(22, 4., 1.)
 30ops.node(23, 4., 2.)
 31ops.node(24, 4., 3.)
 32ops.node(25, 4., 4.)
 33
 34ops.nDMaterial('ElasticIsotropic', 1, 1000, 0.3)
 35
 36ops.element('quad', 1, 1, 6, 7, 2, 1, 'PlaneStress', 1)
 37ops.element('quad', 2, 2, 7, 8, 3, 1, 'PlaneStress', 1)
 38ops.element('quad', 3, 3, 8, 9, 4, 1, 'PlaneStress', 1)
 39ops.element('quad', 4, 4, 9, 10, 5, 1, 'PlaneStress', 1)
 40ops.element('quad', 5, 6, 11, 12, 7, 1, 'PlaneStress', 1)
 41ops.element('quad', 6, 7, 12, 13, 8, 1, 'PlaneStress', 1)
 42ops.element('quad', 7, 8, 13, 14, 9, 1, 'PlaneStress', 1)
 43ops.element('quad', 8, 9, 14, 15, 10, 1, 'PlaneStress', 1)
 44ops.element('quad', 9, 11, 16, 17, 12, 1, 'PlaneStress', 1)
 45ops.element('quad', 10, 12, 17, 18, 13, 1, 'PlaneStress', 1)
 46ops.element('quad', 11, 13, 18, 19, 14, 1, 'PlaneStress', 1)
 47ops.element('quad', 12, 14, 19, 20, 15, 1, 'PlaneStress', 1)
 48ops.element('quad', 13, 16, 21, 22, 17, 1, 'PlaneStress', 1)
 49ops.element('quad', 14, 17, 22, 23, 18, 1, 'PlaneStress', 1)
 50ops.element('quad', 15, 18, 23, 24, 19, 1, 'PlaneStress', 1)
 51ops.element('quad', 16, 19, 24, 25, 20, 1, 'PlaneStress', 1)
 52
 53ops.fix(1, 1, 1)
 54ops.fix(6, 1, 1)
 55ops.fix(11, 1, 1)
 56ops.fix(16, 1, 1)
 57ops.fix(21, 1, 1)
 58
 59ops.equalDOF(2, 22, 1, 2)
 60ops.equalDOF(3, 23, 1, 2)
 61ops.equalDOF(4, 24, 1, 2)
 62ops.equalDOF(5, 25, 1, 2)
 63
 64ops.timeSeries('Linear', 1)
 65ops.pattern('Plain', 1, 1)
 66ops.load(15, 0., -1.)
 67
 68ops.analysis('Static')
 69ops.analyze(1)
 70
 71# - plot model
 72opsv.plot_model()
 73plt.axis('equal')
 74
 75# plt.figure()
 76opsv.plot_loads_2d()
 77
 78# - plot deformation
 79opsv.plot_defo(unDefoFlag=1)
 80plt.axis('equal')
 81
 82# get values at OpenSees nodes
 83sig_out = opsv.sig_out_per_node()
 84
 85# !!! select from sig_out: e.g. vmises
 86# j, jstr = 0, 'sxx'
 87j, jstr = 1, 'syy'
 88# j, jstr = 2, 'sxy'
 89# j, jstr = 3, 'vmis'
 90# j, jstr = 4, 's1'
 91# j, jstr = 5, 's2'
 92# j, jstr = 6, 'alfa'
 93
 94nds_val = sig_out[:, j]
 95
 96plt.figure()
 97opsv.plot_stress_2d(nds_val)
 98
 99plt.show()
100
101exit()