Answer:
Bolt holes in thin-walled cross-sections calculated with the “Thin-Walled Analysis” design method can be modeled using null elements.
In general, you can use null elements to bridge failure locations or holes in the cross-section, for example, if the cross-section only has a hole at this analyzed member location and before / after the complete cross-section provides the connection in the member. Using the null element, it is possible to transfer the shear in the failure location, and also to apply Steiner's components to the section properties.
In the case of a null element, the thickness t is equal to zero. For the calculation of shear stresses, the thickness of the adjacent elements is used as usual, as these elements exist in front of and behind the hole (viewed in the longitudinal direction of the member). For the shear thickness t *, we recommend specifying the thickness of the thinnest element adjacent to the null element.
