In some cases, rather than entering a custom failure distribution by directly specifying the Fraction Failed, you may wish to use an external function to specify the custom failure distribution. This may be useful, for example, if the failure distribution is relatively complex and varies from realization A single model run within a Monte Carlo simulation. It represents one possible path the system could follow through time. to realization.
To facilitate this, GoldSim allows you to define a failure distribution by entering a link representing a 1-D Table Definition. External elements can produce special outputs representing look-up tables.
The Table Definition for a failure mode must be a 1-D Table Definition output produced by an External element. The independent variable for the table must have dimensions An output attribute for an element that defines the dimensionality (in terms of Length, Time and other fundamental dimensions) of the output. of time (which represents the Effective Time for the failure distribution), and the dependent variable must be dimensionless. In addition, the dependent variable for the table should must be greater than or equal to 0 and less than or equal to 1, and can never decrease as a function of time.
Note that GoldSim does not extrapolate the table in either direction. That is, if the table terminates at a Fraction Failed which is less than 1, GoldSim does not extrapolate the table (i.e., barrier failure is assumed to stop). Also, if the table starts at a Fraction Failed greater than 0, it is assumed it is zero at all previous times.