Abnormal nonlocal scale effect on static bending of single-layer MoS₂.

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• Nonlocal Euler-Bernoulli beam theory is crucial for modeling nanoscale structures.
• Single-layer molybdenum disulfide (SLMoS2) is a 2D material with potential engineering applications.
• Accurate evaluation of nonlocal parameters is essential for reliable simulations.

Purpose of the Study:

• To evaluate the nonlocal scale parameter for SLMoS2 beams under static bending.
• To investigate the bending response of SLMoS2 nanostructures using nonlocal beam theory.
• To propose a modified nonlocal constitutive relation for SLMoS2.

Main Methods:

• Molecular mechanics simulations were employed to obtain deflection data.
• Fitted curves of maximum deflection versus beam length were analyzed.
• A modified nonlocal constitutive relation was developed based on simulation results.

Main Results:

• An abnormal sign in the second-order term of deflection was observed for SLMoS2, differing from graphene.
• A modified nonlocal constitutive relation with a positive higher-order term was proposed for SLMoS2.
• The nonlocal scale parameter significantly impacts SLMoS2 bending for lengths below a critical value.

Conclusions:

• The study provides a new perspective on applying nonlocal beam theories to quasi-2D nanostructures like SLMoS2.
• The findings are valuable for researchers focusing on the engineering applications of 2D materials.
• Accurate nonlocal parameter extraction is vital for predicting the mechanical behavior of SLMoS2 nanostructures.