A Hydrocode Material Model for Concrete

In order to predict the behavior of concrete structures under impulsive loading it is not only essential to be able to model the dynamic strength and other strain rate dependent properties of the material, but also to describe realistically the damage and the softening process of the material. Various material models representing different phenomena of the response of concrete to high dynamic loads have already been developed. However, concrete modeling, especially damage modeling, is still far from completion. This paper presents an enhanced material model (HPG) for the simulation of concrete subjected to high dynamic loads. It combines existing approaches from different material models and new formulations for the dynamic strength increase, damage and degradation. The model is based on static material behavior and extends it to the high dynamic range. The formulations for yield surface, plastic hardening and strain rate dependency are presented and the damage and degradation models are explained in detail. The model was implemented in the commercial hydrocode Autodyn and validated both by contact detonation and large caliber impact tests.