HOMOGENIZED CRACK MODEL FOR FINITE ELEMENT ANALYSIS OF CONCRETE FRACTURE

초록

Since quasi-brittle materials like concrete show strain localization behavior accompanied by strain softening, a numerical drawback such as mesh sensitivity is appeared in the finite element analysis. In this study, the so-called homogenized crack model is introduced for three dimensional finite element analysis of fracture in concrete both under tension and under multi-axial compression. A homogenization technique for a homogenized crack element having a velocity discontinuity is employed to remove the mesh sensitivity in finite element analysis of concrete fracture. A conventional elasto-plastic algorithm with an exponential softening rule in which the thickness of the crack is implicitly retained is applied for the constitutive model of tensile fracture and a Drucker-Prager type model with an exponential type of softening parameter is also applied for the constitutive model for compressive fracture of concrete under low confining pressure. Numerical examples show that softening behavior of concrete fracture is successfully predicted without mesh sensitivity using the homogenized crack model