154 Pages

Risk based inspection and maintenance planning

Rigorous integration of maintenance cost of inspection and repairs for structural components making use of realistic failure models started by the last author and his coworkers in Streicher & Rackwitz (2003) and Streicher & Rackwitz (2004) based on the work by Barlow & Proschan (1965) but especially by Fox (1966). This continued in Streicher et al. (2006) by extending the considerations to existing structures and age-dependent and block repairs. In Streicher & Rackwitz (2004) and Rackwitz & Lentz (2006) successful attempts have been made to cover also series systems. In all this work it was assumed that no-repair/repair events and failure events are independent and repair times are negligibly short as compared to the failure times. But this is rarely realistic since inspection results and consecutive repair decisions and failure events most often depend on the same physical deterioration processes and, therefore, inspection results, repair and failure events become highly dependent. This last aspect was studied recently by Joanni & Rackwitz (2006) with promising results. They are generalized herein. Infinitely short renewal times are generally only a simplification.