Basic concepts

In inflatable structures, they can be supported by air (large covered spaces of which membrane is hold in place by the overpressure of the interior with respect to the outside) or in the form of pneumatic structural elements inflated to pressures much higher than the previous ones like arches, bars, etc. .

WinTess3 and pressure

An action of pressure in WinTess3 program is applied through the window of surface loads which can be accessed by F6 key or the menu Calculate | Surface loads.

The pressure checkbox is active only if the building is Pneumatic or Manual. In other cases, the box is inactive. The pressure value is inserted in kg/m². This pressure is applied to each element perpendicularly and the distribution to each vertex is done in the same way as that has been mentioned in the paragraph of actions of wind.

It is very important to consider the direction of the forces produced by the pressure. WinTess3 assumes that the face that is drawn in yellow color is the inside face and that is drawn in blue color is the outside. Therefore the actions of the pressure always pushes the yellow-face of the membrane. If we want it to be upside down, we must reverse the elements using the menu Elements | Reverse.
We can visualize the pressure loads applied by the button on the right .