Cross-sectional area
= Cross-sectional area
{title2=$\mathcal A$}
The <area> of a planar section through a body. A homogeneous diagonal deformation with transverse <stretch ratios> $\lambda_1$ and $\lambda_2$ changes the area of a transverse section from $\mathcal A_0$ to $\mathcal A=\lambda_1\lambda_2\mathcal A_0$. <Cauchy stress tensor> components use current <cross-sectional area>, whereas nominal <tractions> use reference <cross-sectional area>.