Blast response of field objects

During the last few decades, several major industry accidents occurred across the world. These include the Buncefield event in the United Kingdom (UK) back in 2005. There were a number of steel switch boxes in the site located within the area covered by the vapour cloud. The present work reports numerical studies on the steel boxes covering both detonation and deflagration scenarios and assessing the response of those boxes in order to aid the investigation of the explosion. New Eulerian capabilites in ABAQUS has are together with existing Lagrangian formulations to create three numerical models with increasing complexity: (1) Pure Lagrangian model; (2) Uncoupled Eulerian - Lagrangian model; (3) Coupled Eulerian - Lagrangian model. Results from different modelling approaches are discussed and parametric studies are carried out based on Pure Lagrangian models to investigate the response of the switch box to a series of combination of pressures and impulses. Findings from the parametric study are summarised in the form of pressure - impulse diagrams and residual deformation of selected boxes are presented. The results confirmed the estiamted minimum overpressure level of 200kPa and it can also be concluded that the overpressure wave inside the cloud is most likely to be of a deflgrative form. The forensic study described in this paper has gives a good insight into the likely loading scenarios. The study presents a systematic approach for analysing the response of small objects to various blast loadings and the results have shown sthat the forensic studies can be undertaken by using the pressure - impulse diagrams in conjunction with damaged residual deformations.