Three-dimensional homogenized crack model for tensile fracture of concrete

초록

Tensile cracking and subsequent failure of a notched concrete in uniaxial tension is considered to investigate the strain softening behavior of a brittle material. A homogenization technique together with a velocity discontinuity is employed to prevent mesh sensitive behavior of the strain softening material and, using these, a three-dimensional constitutive model involving tensile cracks is derived. It is shown that the thickness of the tensile crack is efficiently removed and, therefore, the stiffness or the softening modulus of the concrete becomes independent of the mesh size. A numerical example in the space of one-, two- and three dimensions is introduced to verify the proposed model and it is found that the softening regime of the cracked concrete is successfully modelled with the proposed homogenized crack element. Future studies will be concentrated on the interlocking crack model and, therefore, a more realistic analysis can be foreseen.