A Complete Nonlinear Finite Element Analysis for the Effects of Surface Explosions on Buried Structures

摘要

Design of structures subjected to dynamic destructive loads is receiving increasing interest due to recent severe damage caused by strong earthquakes and terrorist attacks. For a proper design of buried structures to be conducted, the whole system behaviour including the explosion of the explosive charge, propagation of shock waves through the soil medium, the interaction of the soil with the buried structure and the structure response needs to be simulated in a single model. Such a model will enable more realistic simulation of the fundamental physical behaviour. This paper presents a new complete model simulating the whole system. The Arbitrary Lagrange Euler Coupling formulation is used to model the soil region near the explosion to eliminate the distortion of the mesh under high deformation while the conventional finite element method is used to model the rest of the system. The elasto-plastic Drucker-Prager Cap model is used to model the soil behaviour. The explosion process was simulated using the Jones-Wilkens-Lee equation of state. The contact interface between soil and structure is simulated using the general Mohr-^sCoulomb friction concept, which allows for sliding, separation and rebound between the buried structure surface and the surrounding soil. The behaviour of the whole system is evaluated using a numerical example which shows that the proposed model is capable of producing a realistic manner of the physical system behaviour in a smooth numerical process.