Shear torsion

Structural analysis of three different torsional problem, created with TikZ using the 3Dstructuralanalysis package.

Edit and compile if you like:

% Shear torsion
% Author: Marco Castelli
\documentclass[border=10pt]{standalone}
\usepackage{3Dstructuralanalysis}
\begin{document}
\begin{tikzpicture}[coords]
	% Points
	\dpoint{a}{0}{0}{0};
	\dpoint{b}{0}{3.8}{0};
	\dpoint{c}{0}{0}{0.3};
	\dpoint{d}{0}{0.6}{0.3};
	\dpoint{e}{0}{-0.8}{0.3};
	% Torsiona supports and beam
	\dsupport{3}{a}[0][0][1];
	\dhinge{3}{a}[0];
	\dsupport{3}{b}[0][0][1];
	\dhinge{3}{b}[0];
	\dbeam{1}{a}{b};
	% Loads acting on the edge
	\dload{4}{c}[90][90][1][0.1];
	\dload{4}{c}[90][90][-1][-0.3];
	% Notations
	\dnotation{1}{d}{$M_t$}[above left];
	\dnotation{1}{e}{$M_t$}[above left];
	\dnotation{2}{a}{}[below right];
\end{tikzpicture}
%
\begin{tikzpicture}[coords]
	% Points
	\dpoint{a}{0}{0}{0};
	\dpoint{b}{0}{3.8}{0};
	\dpoint{c}{0}{0.5}{0};
	\dpoint{d}{0}{0}{0.3};
	\dpoint{e}{0}{0.5}{0.3};
	\dpoint{f}{0}{-0.8}{0.3};
	\dpoint{g}{0}{1.4}{0.3};
	% Torsiona supports and beam
	\dsupport{3}{a}[0][0][1];
	\dhinge{3}{a}[0];
	\dsupport{3}{b}[0][0][1];
	\dhinge{3}{b}[0];
	\dbeam{1}{a}{b};
	% Load applied on the support and one load
	% at a 't' distance from the edge
	\dload{4}{e}[90][90][1][0];
	\dload{4}{d}[90][90][-1][-0.3];
	% Notations and dimensioning
	\dnotation{1}{f}{$M_t$}[above left];
	\dnotation{1}{g}{$M_t$}[above left];
	\dnotation{2}{c}{}[below right];
	\ddimensioning{yz}{a}{c}{0.8}[$t$];
\end{tikzpicture}
%
\begin{tikzpicture}[coords]
	% Points
	\dpoint{a}{0}{0}{0};
	\dpoint{b}{0}{3.8}{0};
	\dpoint{c}{0}{0}{0.3};
	\dpoint{d}{0}{-0.8}{0.3};
	\dpoint{e}{0}{0}{0.3};
	\dpoint{f}{0}{0.8}{0.3};
	\dpoint{g}{0}{1.6}{0.3};
	\dpoint{h}{0}{2.4}{0.3};
	\dpoint{i}{0}{3.2}{0.3};
	% Torsiona supports and beam
	\dsupport{3}{a}[0][0][1];
	\dhinge{3}{a}[0];
	\dsupport{3}{b}[0][0][1];
	\dhinge{3}{b}[0];
	\dbeam{1}{a}{b};
	% Load applied on the support and one
	% distibuited load along the whole beam
	\dload{4}{c}[90][90][-1][-0.3];
	\dload{4}{e}[90][90][0.7][0];
	\dload{4}{f}[90][90][0.7][0];
	\dload{4}{g}[90][90][0.7][0];
	\dload{4}{h}[90][90][0.7][0];
	\dload{4}{i}[90][90][0.7][0];
	% Notations	
	\dnotation{1}{h}{$m_t$}[above left];
	\dnotation{1}{d}{$M_t$}[above left];
\end{tikzpicture}
\end{document}