$$\eqalign{ & At\,\,the\,\,end\,\,'A'\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,At\,\,the\,\,end\,\,'B' \cr & \,\,\,\,\,\,\,\,\,{{6EI\Delta } \over {{\ell ^2}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{{6EI{\rm A}} \over {{\ell ^2}}} \cr} $$

$$\eqalign{ & At\,\,the\,\,end\,\,'A'\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,At\,\,the\,\,end\,\,'B' \cr & \,\,\,\,\,\,\,\,\,{{6EI\Delta } \over {{\ell ^2}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0 \cr} $$

$$\eqalign{ & At\,\,the\,\,end\,\,'A'\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,At\,\,the\,\,end\,\,'B' \cr & \,\,\,\,\,\,\,\,\,{{3EI\Delta } \over {{\ell ^2}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{{3EI\Delta } \over {{\ell ^2}}} \cr} $$

$$\eqalign{ & At\,\,the\,\,end\,\,'A'\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,At\,\,the\,\,end\,\,'B' \cr & \,\,\,\,\,\,\,\,\,{{3EI\Delta } \over {{\ell ^2}}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0 \cr} $$

$${{PD} \over {2t}}.{{PD} \over {4t}}$$

$${{PD} \over {8t}}.{{PD} \over {8t}}$$

$${{PD} \over {4t}}.{{PD} \over {8t}}$$

$${{PD} \over t}.{{PD} \over {2t}}$$

Extreme fibres

Centroid of the section

At the junction of the flange and the web, but on the web

At the junction of the flange and the web, but on the flange.

Bending and shear

Bending, shear and torsion

Pure torsion

Torsion and shear