Based on the distribution of shear stress and normal stress at limit state on I section beams, the correlativity of combined shear and torsion and combined bending and shear are obtained through the section equilibrium.

Analyzes the reasons of shear distortion and not enough capacity of the shearing machine because of vertical cutting, designs oblique cutting of bars and improves the design of the shearing machine.

FEM-based analysis on the process of tube shear bending;