13.2.4. section_force_diagram_2d (ops_vis)

ops_vis.section_force_diagram_2d(sf_type, Ew, sfac=1.0, nep=17, fmt_secforce='b-')[source]

Display section forces diagram for 2d beam column model.

This function plots a section forces diagram for 2d beam column elements with or without element loads. For now only ‘-beamUniform’ constant transverse or axial element loads are supported.

  • sf_type (str) – type of section force: ‘N’ - normal force, ‘V’ - shear force, ‘M’ - bending moments.
  • Ew (dict) – Ew Python dictionary contains information on non-zero element loads, therfore each item of the Python dictionary is in the form: ‘ele_tag: [‘-beamUniform’, Wy, Wx]’.
  • sfac (float) – scale factor by wich the values of section forces are multiplied.
  • nep (int) – number of evaluation points including both end nodes (default: 17)
  • fmt_secforce (str) – format line string for section force distribution curve. The format contains information on line color, style and marks as in the standard matplotlib plot function. (default: fmt_secforce = ‘b-‘ # blue solid line)


Wy, Wx = -10.e+3, 0.
Ew = {3: ['-beamUniform', Wy, Wx]}
sfacM = 5.e-5
minVal, maxVal = opsv.section_force_diagram_2d('M', Ew, sfacM)
plt.title('Bending moments')


Add support for other element loads available in OpenSees: partial (trapezoidal) uniform element load, and ‘beamPoint’ element load.

See example Statics of a 2d Portal Frame (ops_vis)