MECHANICAL SYSTEM RELIABILITY AND RISK ASSESSMENT

A new methodology is reported for the prediction of the reliability of mechanical structures subject to multiple failure modes, including no ncritical damage. The reduction of system reliability due to accumulat ed damage is quantitatively estimated by updating the critical system failure states at each level of damage. Correlated design variables ar e automatically accounted for in the system reliability calculations. Second-order reliability bounds are reported which are unbiased to the ordering of the events. A system risk assessment methodology is also reported that accounts for the cost of multiple types of failure modes and includes the effect of inspection success on reducing the consequ ences of system failure. Application of the new technology is illustra ted for a simplified system model of an aeropropulsion rotor system. H owever, the methodology is general and is applicable to any engineerin g system.