Hydrogen adsorption-driven nonlinear strain response in smart functional composite coupling vdW surface energy under nonlocal thermal stress gradient

This study explores the nonlinear dynamic behavior of a microstructure system with adsorbed atoms, focusing on the interplay of nonlocal effects, adatom distribution patterns, and temperature influences. The microstructure is designed as a sandwich microbeam, featuring a perforated microcore with a longitudinal array of periodic square holes (PSH) and face sheets made of functionally graded porous (FGP) material. The effective material properties of FGP are calculated using a mixing rule along the thickness direction. Geometrical nonlinearity is addressed through the Von Karman nonlinear assumption, while the size-dependent response of the FGP microstructure is analyzed using the nonlocal elasticity theory. Additionally, the Lennard-Jones potential is utilized to model van der Waals forces between adsorbed atoms and the microstructure surface, accounting for adsorption-induced energy. A nonlinear partial differential equation is formulated using Euler-Bernoulli and Levinson beam theories to describe the dynamic model. The Galerkin method simplifies this into an ordinary differential equation, and the Method of Multiple Scales (MSM) is applied to determine the resonance shift response. Results indicate that perforation properties, thermal loads, and small-scale effects significantly influence the microsystem’s dynamic response. These findings offer valuable insights into how various physical and geometrical parameters impact microstructure performance, laying the foundation for enhanced modeling, design, and control strategies in cutting-edge engineering applications.