Issue 36

A. Namdar et alii, Frattura ed Integrità Strutturale, 36 (2016) 168-181; DOI: 10.3221/IGF-ESIS.36.17 173 Model 1, NSC Model 1, UHPC Model 2, NSC Model 2, UHPC Model 2, NSC Model 3, UHPC Figure 4 : Von Mises or Distortion-energy criterion of different models with final failure. According to Tabs. 3-5 and Figs. 6-8 in cracking moment conditions, the UHPC exhibits more displacement before collapse. In both models, the maximum displacement occurs when the length of crack is less than the half of the beam cross section. Furthermore, both models have the same cross sections but, after crack cross of 25% of the beam’s height, increasing 30% of von Mises stress, beams are collapsed due to rapid reduction of fracture resistance and toughness. The mechanical properties of concrete are important in mechanism failure of the beam and displacement-crack length, von Mises-crack length and von Mises-displacement of beams. NSC UHPC Crack length (mm) Displacement (mm) Crack length (mm) Displacement (mm) 75 7.71 75 11.07 150 14.05 150 20.20 300 18.07 300 26.01 Table 3 : Maximum displacement Vs crack length with applied constant load. NSC UHPC Crack length (mm) von Mises (MPa) Crack length (mm) von Mises (MPa) 75 85.37 75 130.1 150 96.62 150 146.7 300 110.6 300 168.8 Table 4 : Maximum von Mises Vs crack length with applied constant load.