Titel_SS06

Model Uncertainties – the JCSS Probabilistic Model Code “Light”

Following the JCSS Probabilistic Model Code (2001) model uncertainties may be taken into
account in the following ways:

YfM ()X (7.38)

YfM ()X (7.39)

Yf X X (MM M11 2 2, ,..., nnX) (7.40)

where:

Y: structural performance

f(.): model function

M: random variable representing the model uncertainty

Xi: basic variables

X: vector of basic random variables

Particularly for non-linear model functions Equation (7.40) gives the best way to introduce
model uncertainties. However, this model needs information, which is in general not
available. Usually the model uncertainty is taken into account in the form of Equations (7.38)

• (7.40) or a combination of both.