An Improved Materials Damage Model to Predict High Strain Rate Ductile Fracture

Computational methods are used to interpret the signature of the debris field produced due to impact with an interceptor and to predict the distribution of the debris field over time. The computational methods rely on accurate materials damage model that can predict the progression of damage to fragmentation. Peridynamics, an updated mesh-free continuum mechanics method, provides a theoretical basis to model fracture and defects in a continuum solid without special treatment to handle discontinuities and without costly re-meshing to account for large strains. Peridynamics has been well demonstrated as a method to simulate fracture in brittle materials, but has historically exhibited inaccuracy when applied to ductile fracture. Phase I of the project demonstrated an elastic-plastic materials model with significant improvement in the accuracy of predictions of ductile failure over a range of strain rates. This translates to more accurate predictions of fragmentation patterns with improved efficiency compared to other continuum mechanics based methods. In Phase II, the improved models will be integrated into a LagrangianEulerian modeling framework to simulate debris patterns that arise during system level tests of high velocity impacts. The methodology will be verified and evaluated by comparison of model predictions to archive test data. Approved for Public Release | 16-MDA-8951 (15 December 16)