Filtern
Erscheinungsjahr
- 2018 (3) (entfernen)
Dokumenttyp
- Vortrag (3)
Sprache
- Englisch (3)
Referierte Publikation
- nein (3)
Schlagworte
- Risk (3) (entfernen)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (3) (entfernen)
Identifying optimal inspection and repair strategies for offshore jacket structures is a challenging task. We pre-sent an approach, which is based on recent developments in the field of risk-based operation and maintenance planning at the structural system level. The approach utilizes heuristics to define inspection and repair strate-gies at the system level and to reduce the search space of possible strategies. For each defined strategy, the expected service life cost of inspection, repair and failure is evaluated based on simulated inspection and re-pair histories. Subset simulation is applied to compute the conditional repair and failure probabilities required for this analysis. It also forms the basis for simulating inspection and repair histories. The strategy that mini-mizes the expected service life cost is the optimal one in the set of pre-selected strategies. The underlying condition and performance model accounts for the stochastic dependence among the deterioration states of the different structural elements and the structural redundancy. The approach is demonstrated in a case study considering a jacket-type frame. In this study, we essentially vary the inspection interval, the minimum num-ber of inspected components and the target reliability, and identify the combination that minimizes the ex-pected total service life cost.
The presentation is divided in two parts, each evaluates a different aspect of safety.
It starts with the analysis of consequences resulting from worst case ruptures of gas cylinders. The number of harmed persons and fatalities dependent from the pressure-volume product and the kind of stored gas. In parallel, there is a national accepted rule for accepted failure rates depending from this pV-product created by BAM. When combining both aspects it become clear that the pressure-volume product can be used as a good indicator for consequences. At a level of about 120 MPa m3 the maximum consequence starts to become catastrophic character. This shows the reason why the representatives of DIN insisted in limiting relevant pV-limits for tubes and cylinders to 1 Mio. bar litres.
The second part gives a raff overview on the parameters influencing the acceptance rates of borderline basic populations. This is added by some slides giving an idea for the improvement of the minimum burst requirement and finally completed by a proposal for improved acceptance criteria for the burst test.
The basic idea is: an increased pV-product of tubes has the be reflected by an increased safety level.
The presentation explains the intended way of BAM in tackling the safety issues in the project TAHYA.
The way how the term “safety” is used in TAHYA leads to the need for a more risk-based understanding of safety. Based on this, the Monte Carlo simulation is used to show where the weak points of current regulations are. Thus, a concept for optimization of relevant regulations, codes and standards will be elaborated during the project. For this purpose, it is helpful to improve the currently operated tool for Monte Carlo simulation, which will need additional data for monitoring the outcome. Strength data, that will be determined by BAM and the other partners during the already agreed test program can be used for this purpose without additional effort.