This crate is a simple implementtion of a Timoshenko Beam in 3D

The crate is built upon the work by Yunhua Luo "An Efficient 3D Timoshenko Beam Element with Consistent Shape Functions"
Adv. Theor. Appl. Mech., Vol. 1, 2008, no. 3, 95 - 106

The stiffness matrix is computed as per the Appendix A of the paper.