Issue 43

F. Berto et alii, Frattura ed Integrità Strutturale, 43 (2018) 1-32; DOI: 10.3221/IGF-ESIS.43.01 1 Frontiers of fracture and fatigue: Some recent applications of the local strain energy density F. Berto, S.M.J. Razavi, J. Torgersen Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Norway filippo.berto@ntnu.no , javad.razavi@ntnu.no , jan.torgersen@ntnu.no A BSTRACT . The phenomenon of brittle fracture occurs too often in various branches of engineering being the reason of unexpected termination of anticipated service lives of an engineering objects. This leads to unfortunate catastrophic structural failures resulting in loss of lives and in excessive costs. The theory of fracture mechanics enables the analysis of brittle and fatigue fracture and helps to prevent the occurrence of brittle failure. This field has engaged researchers from various fields of engineering from the early days until today. As its own scientific discipline, it is now less than fifty years old and encourages scientists and engineers to speak the same language when dealing with the design and manufacturing of the classical machinery as well as various intricate devices of nanometer scale, or even smaller, reasoning significant scale effects that arise. Attempting to strike a common ground will connect various physical events/phenomena as a natural result of curiosity arising in course of joint research activities. The interpretation provided by the strain energy density to face different problems and applications is presented in this paper considering some recent outcomes at different scale levels. K EYWORDS . Strain Energy Density; Control radius; Finite size volume; multiscale; Additive materials. Citation: Berto, F., Razavi, S. M. J., Torgersen, J., Frontiers of fracture and fatigue: Some recent applications of the local strain energy density, Frattura ed Integrità Strutturale, 43 (2018) 1-32. Received: 27.09.2017 Accepted: 30.10.2017 Published: 01.01.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION he phenomenon of brittle fracture is encountered in many aspects of everyday life and many catastrophic structural failures involving loss of life have occurred as a result of sudden, unexpected failure. The field of fracture mechanics and the fatigue behavior of structural materials is focused on the prevention of brittle fracture and, as a scientific discipline in its own right, is less than fifty years old. However, the concern over brittle fracture is not new and the origin of the design to ensure safety of structures against sudden collapse is very old. This topic has involved many researchers in different engineering fields from ancient time to nowadays. Materials may fail at different scale levels with some similarities in the final behavior but also with strong scale effects characterizing the different scales of observation. T