แบบจำลองคานขนาดไมโคร-นาโนเมตร บนชั้นรองรับแบบอีลาสติก

Abstract

In recent years, micro-nano technology has found many applications in science and engineering fields as well as in structural engineering. Therefore, the micro-nano sized beam-elastic substrate element models have been developed in this research. The modified couple stress and the nonlocal elastic theories are employed to account of the core-sized effect while the surface elastic theory is used to capture the surface-layer effect. The interaction between the beam and the substrate is represented by the Winkler-foundation model and Van der Waals force theory for linear and nonlinear behavior, respectively. Due to similarity between the beam on Winkler-Pasternak foundation and the models in this research, the procedure of "natural" beam on Winkler-Pasternak foundation is employed to develop beam on linear elastic substrate models. The finite-element method is employed to obtain the beam on nonlinear elastic substrate model. Two numerical examples for each model are used to study the characteristics and behaviors of beam substrate system.