Inelastic deformation and failure of partially strengthened profiled blast walls

Blast walls that separate the potentially hazardous regions of the topside on an offshore platform were designed to resist lower loads than those envisaged today thus it is desirable to upgrade their blast resistance in a cost-effective and non-intrusive manner. One proposal is to retrofit the existing blast walls partially with centrally located composite patches. This study presents an assessment tool, which provides understanding of the effect of a composite patch on the blast resistance of blast walls. Numerical simulations of a proposed retrofitted wall are performed to gain insight into the failure progression of the wall ab initio. Damage in the composite patch was considered, and the numerical simulations showed that fiber fracture did not occur thus there was no significant loss of in-plane stiffness and strength. Based on these observations, the rapid assessment tool, analytically formulated to incorporate the effect of the composite patch which strengthens the wall and moves the plastic hinge locations away from the wall centre to the composite-steel edge, is deemed a suitable tool. The assessment tool and the numerical simulations are partially validated by the experimental results. The tool runs quickly and provides reasonable accurate predictions for the deformation response of the walls.