Modeling of concrete failure under blast and fragment loading

The defense community is extremely interested in developing numerical methodologies for predicting the dynamic response of concrete materials under extreme loading conditions. This capability would make it possible to use computer software for simulating events of interest, such as the response of concrete structures or structural components to blast and fragment impact. Over the years, substantial effort has been invested in researching analytical models and methods to develop this capability. Most of this effort has focused on in improving methodologies that are based on continuum mechanics. However, (classical) continuum mechanics is not well suited for the simulation of concrete failure and post-failure behavior. This is mainly due to the non-homogenous nature of concrete as well as the discontinuous nature of fracture and fragmentation. To overcome these limitations, ES3 and Prof. Cusatis at RPI have jointly formulated and implemented a new innovative methodology: the Lattice Discrete Particle Model (LDPM). LDPM is a methodology that treats concrete at the meso-scale, the scale of the largest aggregate pieces. LDPM models the heterogeneities in concrete and is capable of simulating discrete cracking leading to fragmentation in a physically realistic fashion. The research that ES3 is proposing under this SBIR will address three main issues: • Formulation of LDPM multiscale-multiphysics framework, • Fiber-concrete, rebar-concrete interaction, and • Small scale fragmentation at high strain rates. In Phase I of this SBIR we will evaluate new or improved analytical models and determine the technical feasibility of the proposed concepts.