Fracture mechanics analysis of pre-stressed concrete sleepers via investigating crack initiation length

This paper presents an investigation on pre-stressed concrete sleepers based on the principles of fracture mechanics in concrete material . To evaluate fracture mechanics parameters pre-stressed concrete sleepers with different initiation crack length varying between 0 mm and 45 mm increasing by 5 mm steps are used. A three-point bending loading condition is considered. Finite element software is employed to model the sleepers and to calculate the parameters of fracture mechanics such as K Ic and crack growth. Finally, in this study for validation, load–displacement diagram of 5 experimental samples is compared with numerical model of finite elements for validation of model. The paper shows that an expansion in crack instability follows from increasing crack-to-depth ratio, initial toughness, the crack stability and crack unstable toughness, the crack instability expansion begins. The paper also shows a good agreement between the numerical and experimental results via comparing the results of the 5 samples with the numerical model.