ABSTRACT
This chapter describes full thickness material failure tests. It discusses the background and how full thickness tests on an 8 mm circular plate fit in the framework of Forming Limit Diagram (FLD). The chapter presents the results of the so-called apple core specimens, exhibiting plane strain behavior. The failure of the specimens is depicted in the FLD diagrams, showing the relevance of these tests for updating failure criteria for maritime and offshore impact analysis. In collision analysis, one may want to check full capacity of the ship structure to withstand an impact without endangering the cargo holding capacity and/or people on board. The material strength for impact under multiaxial stress conditions is verified using an experimental test set-up where a full thickness circular plate is subjected to impact loading by a hemispherical punch. Material failure models for steel structures use a failure strain criterion, corrected for element size, applied on the equivalent plastic strain as calculated.
