There is a problem with the ~STAGE1.XSF file that is part of the “Composite floor” example included with iPhone xsec version 5.7.
If the stage 2 computations follow on from stage 1 this file is not used. It is intended to allow the computations to start at stage 2.
This file is not compatible with the step by step instructions. (It is compatible with the Mac & PC version of the instructions although they have not been released yet.) It has the material of “Rib” set as “Air” where as it should be “Rib concrete”.
To correct this add the following to the iPhone instructions step 2-2:
a Tap the “C” at the bottom of the display to change the display to the Components list.
b In that list tap “Rib” to open the component editor for “Rib”.
c The editor display includes a label “Material=” and “Air” in an adjacent selection box. Tap on “Air” and a list of materials should appear.
d In that list select “Rib concrete” and tap “Done”.
e Tap the “<” back button in the top left corner to return to the components list.