In the AISC 360 – 14th Ed. C2.2, the direct analysis method requires initial imperfections to be taken into consideration. The important imperfection of recognition is column out-of-plumbness. According to C2.2a, the direct modeling of imperfections is one method to account for the effect of initial imperfections. However, in many situations, the expected displacements may not be known or easily predicted.
Il processo di form-finding in RFEM cerca uno stato di equilibrio in cui la precompressione definita delle membrane e la precompressione o le variazioni di lunghezza degli elementi di funi con reazioni al contorno sono in equilibrio. Hierbei gibt das Programm die Möglichkeit, einen isotropen oder einen orthotropen Vorspannungszustand für die Membranen zu definieren.