Gradient-Enhanced Smeared Crack Models for Finite Element Analysis of Plain and Reinforced Concrete

gradient-enhanced smeared crack model is utilised element simulations of and reinforced concrete. It is rooted a plasticity concept and uses a Rankine failure dependent on an equivalent strain measure, as well as on Laplacian. loss of well- posedness of boundary value at the onset avoided, and finitely sized fracture process zones are .._, ............ A,.A,._,, ...... Edge-Notched concrete specimen loaded in a combination tension and shear is analysed the results are verified against the experimental data. A reinforced concrete bar uniaxial tension is calculated to evaluate regularising on reinforced concrete structures. 1 a proper judgement of the structural safety of a system it is necessary to assess the danger of a sudden (brittle) failure after attaining limit load. Structural concrete exhibits a softening behaviour due to non- homogeneous deformations resulting from cracking, & Hegemier (1984). Therefore, there exists a demand for reliable computational meth- capable of reproducing the post-peak behaviour. Classical, local constitutive models embody the AAAA·~~~~ assumption the deformation of the specimen varies in a smooth man- ner. This is not the case when strain ... ..., .............. u ........... './ 871 cracks develop during fracture). Nevertheless, a variety of smeared crack- ing, plasticity or damage based strain softening models exist, which fea- ture a descending relation between stress and strain. The mathematical implication of such a constitutive relation within the classical continuum description is the loss of well-posedness of a given boundary value prob- lem. The consequence numerical simulations is a pathological discreti- sation sensitivity (e.g., Sluys, 1992). overcome this difficulty one can concentrate the damage evolution a discontinuity (e.g. introduce discrete cracks between continuous parts of a concrete structure).