Compute torsion constant vector

[carlos-adir]

To compute the torsion constant, the following quantity must be computed

$$\mathbb{J}_{\omega} = \int_a^b \omega \ \langle \mathbf{p}, \ \mathbf{p}'\rangle \ dt$$

So, the torsion constant vector is given by

$$\mathbb{J}_{\omega j} = \int_a^b \varphi_j \cdot \langle \mathbf{p}, \ \mathbf{p}'\rangle \ dt$$

And it's valid for any type of geometry.