Within the Sloshel Joint Industrial Project, a new full scale wave impact test campaign has been carried out in April 2010. Unidirectional focused waves were generated in a flume in order to impact a rigid wall in which an instrumented Mark III LNG containment system panel had been embedded. The wall was entirely covered with the Mark III corrugated membrane in the same way as on board a LNG carrier. During one of the last tests of the campaign a flip-through type of impact was generated and very high local pressures were measured. The horizontal small corrugations of the membrane were significantly deformed but no permanent deformation of the foam was observed by initial visual inspection. After removing the Mark III panel and cutting it into small blocks, no discernible cracking, no discernible permanent deformation and no discernible change of the initial properties were observed.
The aim of the Sloshel full scale Mark III tests was to study some key issues related to sloshing impacts in tanks of Mark III LNG vessels through impact tests of breaking waves in a flume. Although obviously not identical to the real conditions, the conditions induced by impacts of breaking waves in a flume with water and air on a real Mark III containment system are considered to be relevant for studying fluid-structure interactions, scaling effects by comparison with a previous test campaign at scale 1:6 and wave-corrugation interactions. These tests also enabled the building of a reference data base for validation of numerical simulations. As the loads generated by the water are almost twice as large as those generated by LNG for similar waves due to the ratio of densities, caution was taken in order to not damage the membrane or the containment system before having stored enough data.