Dynamic Behavior of Concrete: Constitutive Models - Dynamic Behavior of Concrete and Seismic Engineering - page 55

Chapter 2
Dynamic Behavior of Concrete:
Constitutive Models
2.1. Dynamics of concrete structures
2.1.1. Macroscopic phenomena
We can distinguish two structural response levels to a dynamic load: the local
level and the overall level.
2.1.1.1. Local effect of an impact
This is the stress and strain state created inside the impact area. This state
develops simultaneously with loading and for very high strain rates. Studying the
local effect requires taking the inertia effects, wave strain propagation and tri-axial
stress states into account. Whenever failure criteria are reached during this phase,
scabbing and shear phenomena with chip projections will take place.
2.1.1.2. Overall effect on a structure
If loading is globally distributed on the structure, or if, in the case of an impact,
local failure conditions have not been fulfilled, then the whole structure responds
dynamically. The inertia effects of the structure are such that the reaction
immediately follows loading. If loading results from an explosion or a soft shock,