# SHAPE‑THIN calculates a very small shear area. Why?

The shear area is calculated as follows:

${\mathrm A}_{\mathrm y}\;=\;\frac{{\mathrm I}_{\mathrm z}^2}{\int_{\mathrm A^\ast}\left({\displaystyle\frac{{\mathrm S}_{\mathrm z}}{\mathrm t^\ast}}\right)^2\operatorname d\mathrm A^\ast}$

${\mathrm A}_{\mathrm z}\;=\;\frac{{\mathrm I}_{\mathrm y}^2}{\int_{\mathrm A^\ast}\left({\displaystyle\frac{{\mathrm S}_{\mathrm y}}{\mathrm t^\ast}}\right)^2\operatorname d\mathrm A^\ast}$

where

 Iz or Iy is the second moment of area in relation to the axis z or y, Sz or Sy is the first moment of area in relation to the axis z or y, t* is the effective element thickness for the shear transfer, A* is the surface area based on the effective shear thickness t*.

The effective element thickness for the shear transfer t* has a significant influence on the shear area. Therefore, the defined effective element thickness for the shear transfer t* (Figure 01) of the elements should be checked.