Static assessment of nanoscale notched silicon beams using the averaged strain energy density method

•Theoretical critical SED is redefined by using the ideal fracture stress.•The SED control volume is evaluated by using the TCD characteristic length.•The SED combined with the TCD gives a control volume of 1.4 nm.•The critical SED at the nanoscale is 0.7431GJ/m3.•The static loads at fracture of nanoscale notched specimens are successfully estimated. This paper extends the averaged Strain Energy Density (SED) method to the static assessment of notched components at the nanoscale. First, in situ micromechanical testing of notched nano-cantilever beams made of single-crystal silicon is briefly reviewed. Then, an alternative strategy based on the Theory of Critical Distances is employed to evaluate the control volume and the critical SED. The method is later verified against experiments and FE analyses. The SED method successfully estimates the load at fracture of nanoscale notched specimens with a maximum discrepancy of 4.7%. Moreover, the method is mesh-independent, and therefore very coarse meshes can be employed in numerical analyses. Finally, the results are discussed on the basis of the breakdown of continuum fracture mechanics at the nanoscale. The extension of the SED approach to the micro- and nanoscales provides a fast and simple tool for the design of micro- and nanodevices.