45°载荷作用下单分子层的微屈曲分析

MICROBUCKLING FOR MONOMOLECULAR LAYER ADHERING TO A SUBSTRATE UNDER THE COMPRESSIVE FORCE WITH AN ANGLE OF 45°TO THE CHEMICAL BOND

通过发展Ｃｈｉｓｋｓ和Ｐａｒｎｅｓ提出的弹簧模型模拟了单分子层的微屈曲现象，结果显示，单分子层的屈曲模态由其横向抗弯刚度及其与基体间粘结刚度密切相关．随着涂层横向抗弯刚度的升高和涂层与基体粘结刚度的降低，屈曲模态趋于光滑且临界屈曲载荷降低．单分子层的纵向抗剪能力对其模态值没有影响，但临界屈曲载荷会随纵向抗剪力的增大而减小．此外，还给出了单分子层不发生屈曲的临界判据，对于工程设计具有指导意义．

A thin layer can be formed when one material is coated on the surface of another ma-terial for special purpose, such as for protection, for decoration, for a barrier, or to provide unique surface properties. With the necessity of high developments of modern science and technology, the size of microstructure tends to a molecular scale. In this paper, microbuckling phenomenon is analyzed by a linear spring model for the monomolecular layer adhering to a substrate subjected to compressive force with an angle of π/4 to the chemical bond direction. It is shown that the buckling mode is determined by R, the ratio of the adhesion stiffness to the bending stiffness, and becomes corrugated with increasing R. The critical buckling force decreasing with increasing R and decreasing S, the ratio of the bending stiffness to the shearing stiffness of the layer. Further-more, a criterion for non-buckling condition is obtained, which implies that one can choose suitable material constant to avoid the buckling in engineering application.