2.7.2 Panel

A Panel is a Laminate that is used in a beam. The laminate x-axis is oriented along the length of the beam. The laminate y-axis is oriented from node $n_ i$ to node $n_ f$, which is called s-coordinate in Figure 10.2. The thickness of the laminate is given by the r-axis in Figure 10.2, which is found using the right hand rule, or the cross product $r=x\times s$.
\includegraphics[]{./Images/RightHandRule.png}

The s-direction is important if the laminate is not symmetric. Lamina #1 is located at the bottom of the laminate (s negative). For example, for a $[0/90]$ laminate, the 0 deg lamina should be located at s negative and the 90 deg lamina at s positive to get the correct bending-extension coupling and so on.