Strengthening profiled blast walls and connections using fibre-reinforced plastics

Blast walls are used to limit the destructive effects of a possible gas explosion in an offshore platform by separating the modules from one another. Owing to inadequate blast-resistant capacity of existing blast wall connection systems, strengthening of these structures is required. One approach to solve this issue involves the use of fibre-reinforced plastic composites. In the present study a method has been proposed for optimal strengthening of blast walls and their connections using composite patches. The scheme presented for strengthening blast walls is based on a single parameter used in buckling of plates made of round-house materials and in relation to connections the scheme considers desirable support characteristics. A typical hybrid (steel-composite) system has been analysed both statically and dynamically. Energy absorption capacities of strengthened and unstrengthened systems have been compared and it was observed that increase in the energy absorption capacity is possible provided that there is no damage to the composite patch in fibre breakage mode. This increase is accompanied by large forces being exerted to supporting structures and their vicinity on the profile, which may trigger tearing failure mode. Strengthening patches do not contribute to the energy absorption capacity when there is fibre failure. This is mainly due to the more pronounced opening of connections in a blast load scenario compared to a similar static loading scenario.