the article considers behaviour of a simply supported pre-cracked beam made of elasto-plastic material. The aim of the work is to study propagation of min-span fractures in the beam, defining of its behaviour in the local area and developing of techniques and methods to prevent further growth of a crack. There were applied vary verify methods to analyse deflections, internal forces and stress intensity factor in the area of crack propagation. Analytical and numerical calculation had been used. For numerical solution ANSYS software is used, based on finite element method. According the solutions key features and conclusions are given.

Keywords: fracture, pre-cracked beam, stress intensity factor, load-bearing capacity, elasto-plastic material, finite element method