Abstract:

When common cause failure occurs, the effect of the same cause may show diversity among the units in the common cause component group, or may vary with time. To evaluate the asymmetric time-varying common cause failure, a “random shock-random threshold” model is proposed in order to solve both the asymmetric problem and the time-varying problem together. The model can also be applied in multiple common cause cases. Different from the focus of common cause failure probability, which is only on failure modes, this model can fully investigate different causes and their effects. The feasibility of the model is demonstrated by wind turbines with different threshold distributions, under the destructive shocks caused by wind and wave. The application illustrates that the proposed model provides a unified framework to evaluate the asymmetric timevarying common cause failure in case of either single cause or multiple causes.