Damage assessment of concrete structures based on fractal dimension using nonlinear fracture mechanics cracks simulation

摘要

Damage diagnosis of concrete structures is extremely important and principle task is to extract damage features. The most basic and direct information to characterize damage of concrete structures is the appearance of cracks - formation of cracks pattern. Nonlinear fracture mechanics finite element simulation utilizing fracture mechanics can provide crack patterns at both 2D and 3D levels for the whole process of loading - till the complete failure. The paper proposed a new approach to assess such crack patterns in order to evaluate the damage level virtually. The fractal dimension provides a viable way to assess the severity of concrete damage and has been applied for experiments but not for crack patterns obtained virtually by computational simulation. As computational simulation of crack patterns can be done for any load level, by comparison of virtual crack patterns and real ones, damage level can be evaluated based on fractal (or multifractal) dimensions. The suggested approach can help evaluate the residual resistance of existing structure state, based on comparison of cracks pattern obtained from real structure and from computational modelling.