Issue 42

A. Campagnolo et alii, Frattura ed Integrità Strutturale, 42 (2017) 181-188; DOI: 10.3221/IGF-ESIS.42.19 181 Mode II brittle fracture: recent developments A. Campagnolo Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131, Padova, Italy S.M.J. Razavi, M. Peron, J. Torgersen, F. Berto Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Norway javad.razavi@ntnu.no , mirco.peron@ntnu.no , jan.torgersen@ntnu.no , filippo.berto@ntnu.no A BSTRACT . Fracture behaviour of V-notched specimens is assessed using two energy based criteria namely the averaged strain energy density (SED) and Finite Fracture Mechanics (FFM). Two different formulations of FFM criterion are considered for fracture analysis. A new formulation for calculation of the control radius R c under pure Mode II loading is presented and used for prediction of fracture behaviour. The critical Notch Stress Intensity Factor (NSIF) at failure under Mode II loading condition can be expressed as a function of notch opening angle. Different formulations of NSIFs are derived using the three criteria and the results are compared in the case of sharp V-notched brittle components under in-plane shear loading, in order to investigate the ability of each method for the fracture assessment. For this purpose, a bulk of experimental data taken from the literature is employed for the comparison among the mentioned criteria. K EYWORDS . Fracture strength; Sharp V-notch; mode II fracture; Notch stress intensity factor; Strain energy density. Citation: Campagnolo, A., Razavi, S.M.J., Peron, M., Torgesen, J., Berto, F., Mode II brittle fracture: recent developments, Frattura ed Integrità Strutturale, 42 (2017) 181-188. Received: 28.06.2017 Accepted: 25.07.2017 Published: 01.10.2017 Copyright: © 2017 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 umerous failure criteria have been proposed by scholars dealing with the brittle fracture of V-notches [1]. According to the intensified linear elastic stress at the notch tip, introducing a stress field parameter is useful. Considering the Linear Elastic Notch Mechanics (LEFM) concept, NSIFs can be successfully employed for the fracture assessment of brittle materials when weakened by sharp V-notches [2,3]. Lazzarin et al. [4] compared two widely employed criteria based on energy considering V-notched components under pure Mode I loading; the first criterion is based on the local SED [5] while the second criterion is the so-called FFM approach. Two different formulations of the FFM criterion is available in the literature: the first formulation was proposed by Leguillon [6,7] and the second one was proposed by Carpinteri et al. [8]. The main aim of the current paper is to extend the previous comparison to the case of Mode II loading condition. N