| Summary: | 碩士 === 國立清華大學 === 動力機械工程學系 === 92 === Carbon nanotubes (CNTs) have stimulated wide research activities in recent years because of the merits of their special material, mechanical, thermal and electric properties. The objective of this work is to develop an equivalent continuum mechanics analysis model to make an in-verse-calculation of the material properties of single-walled CNTs fastly and accurately, such as equivalent Young’s modulus and Poisson’s ratio.
Firstly, based on the continuum mechanics analysis, the equivalent spring and beam elements are derived to simulate the bond forces be-tween carbon atoms, respectively. By establishing the finite element mod-els using respective equivalent elements, the inverse-calculation of the material properties of graphite and single-walled CNTs with zigzag and armchair type can be made subjected to different loadings. The compari-sons between the present results and available experimental and simulat-ing data show that the finite element analysis model using equivalent beam elements has higher accuracy.
Finally, the finite element analysis model using equivalent beam elements is adopted to further study the influence of the van der Waals forces on the material properties of single-walled CNTs. The van der Waals forces are simulated by equivalent nonlinear spring elements. It is found that the van der Waals forces have significant influence on the ma-terial properties of single-walled CNTs.
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