Evolution of the mechanical fields and fracture process of S355JR steel

The development of mechanical fields before the crack tip and the appropriate development of the cracking process in S355JR ferritic steel are analyzed. In order to obtain different cracking mechanisms, the tests were carried out in the temperature range from 120 degrees C to + 20 degrees C. Experimental research has been supplemented with the SEM observation of the specimens fracture surface. Specimens modeling and load simulations were performed using the MES in the ABAQUS program. The accurate calibration of the true stress-strain material dependence was made. The distributions of local stresses and strains in front of the crack were determined for specimens tested at different temperatures and revealed, respectively, different fracture mechanisms. The development of mechanical fields at various stages of specimens loading was analyzed. The stress and strain levels were determined, at which different fracture mechanisms (completely brittle, mixed brittle-ductile or completely ductile) realize. (C) 2019 The Authors. Published by Elsevier B.V.