Fracture behaviour of nanobeams through Two-Phase Local/Nonlocal Stress-Driven model

The aim of the present work is to employ the two-phase local/nonlocal Stress-Driven integral Model (SDM) to analyse the size-dependent Mode I fracture behaviour of Bernoulli-Euler cracked nanobeams, in terms of energy release rate, stress intensity factor and nonlocal stress field near the crack tip. Both edge- and centrally-cracked nanobeams, subjected to concentrated forces, are examined. The edge-cracked nanobeam is modelled as a pair of cantilever nanobeams, whereas the centrally-cracked nanobeam as a pair of double-clamped nanobeams with internal discontinuity due to concentrated loads. Moreover, a comparison with the results obtained from a gradient elasticity theory based model, available in the literature, is performed. From the present study, it is observed that the energy release rate decreases by increasing the nonlocality, showing the superior fracture performance of nanobeams with respect to large-scale beams.