# Matplotlib compatibility patch for Pyodide
import matplotlib
if not hasattr(matplotlib.RcParams, "_get"):
    matplotlib.RcParams._get = dict.get

… for torsion

The differential equation for equilibrium relations for bending is based on the infinitesimal small loaded torsional bar:

leading to :

\[{q_{t,z}} = - \frac{{{d}M_t}}{{{d}x}}\]

This is not treated in the books.