Validation of Ductile Metal Rupture/Tearing Material Models for Simulation of Structure/Ice Collision
Abstract
This report documents validation of numerical methods for simulation of rupture and tearing damage inflicted on indenter-loaded thin shell structures. These modeling methods are key to accurate prediction of ice impact loads and resulting structural damage that risk the hull structural integrity of non-ice-reinforced naval surface ships transiting ice-infested waters. Validation is accomplished by successful numerical-mechanics simulation of laboratory experiments. Steel structure rupture and tearing simulations are carried out for three flat panels, all loaded by conically-profiled rigid indenters driven laterally into the panels at effectively static rates until rupture occurs. An unstiffened panel and panels reinforced with one and two flat bar stiffeners are considered, all supported in a rigid box-sided frame. The stress-strain behavior of the steels in all plate and stiffener components is characterized to enable representation of failure strain levels as a function of stress triaxiality through a forming limit diagram approach. This same approach had been used in a prior series of exploratory analyses of notional ship hull structure severely damaged by indenters driven over the hull structure in a raking fashion. The present numerical simulations produce structural displacement, failure load, and fracture pattern results consistent with the laboratory experiments and comparable to those of previous researchers. A moderate degree of mesh sensitivity of predicted failure loads and fracture patterns is observed, especially in the case of the panel reinforced by two stiffeners, for which fracture initiation sites are in zones of extreme strain gradient.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 02, 2020
- Accession Number
- AD1118156
Entities
People
- Douglas E. Lesar
Organizations
- Naval Surface Warfare Center Carderock Division