MODELLING OF CONCRETE DAMAGE

The paper deals with realistic modelling of concrete structures and material damage using nonlinear finite element method. Tensile and shear cracks or compressive crushing develop in concrete due to various reasons and can considerably influence resistance and durability of concrete structures. Numerical investigations have been carried out in order to analyze, predict and prevent concrete damage using nonlinear computer simulation based on advanced material models and finite element methods. The numerical material models for concrete implemented in the nonlinear software ATENA are described. Various sources of damage such as volumetric loads due to concrete shrinkage or irregular temperature distribution, fatigue loading or material degradation can be assumed; relevant numerical procedures are developed and applied. In particular, tensile fatigue model is described more in detail. Fatigue damage of concrete is an important problem in structures subjected to cyclic loading, like railway sleepers, anchoring regions of pre-tensioned bridges, or fundaments of wind power plants. Three-dimensional fracture-plastic model with fatigue extension has been used to simulate high-cycle fatigue of concrete specimens in three-point bending. Comparison of the analysis results to the experimental measurements is presented along with details of the simulation including the material model extension.