We derive a method to determine the effective local elasticity tensor by combining the local stress, local strain, and global strain in conjunction with a linear least-squares solver. This method reduces to the standard stress-strain fluctuation method for the estimation of global moduli if the local stress and the local strain are substituted by global counterparts. The quality of the developed method is verified by the analysis of an fcc Lennard-Jones single crystal. By using this method, surface elastic behaviors of three nanoplates are investigated. Simulation results prove that both softening and stiffening effects could be detected, depending on the surface orientations and loading directions. This approach could be especially valuable for complicated morphologies where the physical properties of the local material are challenging or impractical to obtain.

• Received 15 February 2015
• Revised 14 April 2015

DOI:https://doi.org/10.1103/PhysRevB.91.184104