Spider web in opening

Many engineers use so-called spider webs to distribute the pressure only force from a pin or a bolt inside the hole of a surface. The benefits are that it is common practise and easy to understand. On of the drawbacks is the peak stress in the surface, see the following picture.

In RFEM one can also use the surface type 'Without Membrane Tension'. This surface type distributes the force in the same way, but it doet cause a much smoother distribution of the stress.