Additive manufacturing of miniature marine structures for crashworthiness verification: A numerical revision

Abstract

This work presents a revision of the structural similarity technique developed for the experimental modeling of marine structures subjected to collision, grounding or similar catastrophic events via miniature models with drastic scale reduction. This revision involved basically the inclusion of combined collapse modes to predict the mechanical behavior of structural members and the redefinition of the flow stress range. The revised technique was validated through numerical simulations of the miniature modeling of nine large-scale marine structures’ experiments found in literature and here presented in the form of nine study cases. Each study case evaluates the accumulated effects of scale reduction, thickness distortion and material distortion in the miniature model as part of the similarity technique. In general, a reasonable-to-good correspondence was observed between the force and absorbed energy responses obtained from reference large-scale structures and their miniature models once brought to the same dimensional scale. Discrepancies between structural responses were quantified by evaluating the normalized root mean square error. By these means, most of the study cases presented errors below 12.5% in terms of force response and below 4.5% in terms of absorbed energy response. On the other hand, lower agreement was encountered when reproducing experiments strongly ruled by progressive buckling or crack initiation/propagation together with severe reduction scales. In these cases, better results are achieved when implementing a more accurate material failure model or by moderating the reduction scale.