Consider the initially straight cantilever beam of uniform cross section shown in Fig. 2 with general loads at its free end. The force at the free end is divided into its horizontal and vertical components, *F*_{x} and *F*_{y}, respectively. A moment *M*_{z}, also acts at the tip of the beam. The inset shows a segment of the beam at a distance $s\u2208[0,L]$ along the length of the beam. It is subjected to an axial force *P*(*s*), a shear force *V*(*s*), and a bending moment *M*(*s*). The beam element is rotated by an angle *θ* to the *x*-axis, and the cross section is rotated by a angle *ψ* to the *y*-axis. It is assumed that the cross section remains planar and is not distorted by the loads acting on the beam. The initial dimensions of the beam are length, *L*_{0}, area *A*_{0}, and second moment of area *I*_{0}.