2430x
002110
2019-11-12

Question

How do RFEM and RSTAB calculate the moment of inertia Iy of a castellated beam from the library?


Answer:
RFEM and RSTAB calculate a reduced moment of inertia Iy according to the article "Bemessung von Wabenträgern" by R. Kindmann, H. J. Niebuhr, H. Schweppe.

The reduced moment of inertia Iy for WAB HEB 340‑340, for example, is calculated as follows:

red Iy = 0.8 * A * ((H - tg) / 2)2

red Iy = 0.8 * 150.50 * ((51.00 - 2.15) / 2)2 = 71,828 cm4