Issue 36

A. Namdar et alii, Frattura ed Integrità Strutturale, 36 (2016) 168-181; DOI: 10.3221/IGF-ESIS.36.17 172 crack, and the movement of stress along the beam, fracture resistance and toughness of the beam are reduced. The tensile strength has directly related to the fracture resistance and the stress was distributed according to length of crack. It has been observed that the crack develops with stress transfer and effect on stress, von Mises, load reaction, displacement and length of crack. The material’s fracture resistance is important in crack extension. The fracture characteristics of beam influence the stress and deformation behavior of beam. The fracture characteristics depend on strength of material. The crack extension depends on elastic strain energy at fracture. With the increase the toughness of plain concrete the brittleness of concrete is reduced and the fracture resistance increases and caused the change of stress path during the beam is under cracking extension process. The fracture toughness of a material depends on material mechanical property. The maximum concrete interaction was observed in fully collapsed beam, it depends on mechanical property of concrete. Accordingly, a design engineer would be understand that this concept help them to predict failure mechanism of concrete structure, which is failed under flexural failure and considering deformation and fracture resistance of the beam material. The strength of the material effects on stress path, fracture resistance and toughness mechanism of plain concrete beam. The failure occurs when elastic energy-release rate equals the rate change in material resistance and completed flexural crack shape on the beam. In Figs. 3-5 are shown displacement, von Mises and load reaction of different models up to final failure. It has been shown that the maximum displacement occurs in the center of the beam. Due to fixed both side of the beam, there is any displacement observed at the end of the beam. In the NSC and UHPC beams, stress and load reaction path are the same, but displacement, von Mises and load reaction magnitude are different. It is observed that there are direct influences between crack length and displacement, von Mises and load reaction of the beam. Model 1, NSC Model 1, UHPC Model 2, NSC Model 2, UHPC Model 2, NSC Model 3, UHPC Figure 3 : Displacement of different models with final failure Vs crack length.