本文選題：石墨烯 + 分子結(jié)構(gòu)力學(xué)　； 參考：《西安建筑科技大學(xué)》2016年碩士論文

【摘要】：石墨烯具有優(yōu)良的力學(xué)、電學(xué)、熱學(xué)特性,自從2004年被發(fā)現(xiàn)以來一直被國(guó)內(nèi)外學(xué)者廣泛研究,其顯示出的獨(dú)特的性質(zhì)被認(rèn)為是具有戰(zhàn)略意義的新型碳材料。其各項(xiàng)力學(xué)性能的研究也是國(guó)內(nèi)外力學(xué)學(xué)者的研究熱點(diǎn)。本文主要基于分子結(jié)構(gòu)力學(xué)理論,利用有限元方法對(duì)石墨烯的彈性性能和振動(dòng)特性進(jìn)行研究。通過分子力學(xué)理論中原子間勢(shì)能與宏觀結(jié)構(gòu)力學(xué)理論中梁的應(yīng)變能之間的等價(jià)關(guān)系,建立了能模擬C-C共價(jià)鍵的圓形截面梁?jiǎn)卧２捎梅肿觿?dòng)力學(xué)理論中的Morse勢(shì)函數(shù)模擬C-C鍵的非線性關(guān)系,采用集中質(zhì)量單元模擬碳原子,建立了石墨烯框架結(jié)構(gòu)連續(xù)介質(zhì)模型,并且利用有限元方法對(duì)模型進(jìn)行計(jì)算分析。對(duì)于完美的石墨烯,本文分別研究了扶手椅型和鋸齒型兩種手性的石墨烯,在尺寸方面分別研究了不同長(zhǎng)寬比和不同尺寸的石墨烯。對(duì)于含缺陷的石墨烯主要研究了含有不同數(shù)量空位缺陷、不同尺寸的空洞缺陷以及不同位置和長(zhǎng)度的裂紋的石墨烯�；谝陨喜煌愋偷氖�,分別研究了其彈性性能和振動(dòng)特性。在彈性性能方面主要研究了楊氏模量和泊松比等彈性性能參數(shù),在振動(dòng)特性方面主要研究了含基頻的前五階固有頻率和各階振型。經(jīng)過以上研究主要得出了如下結(jié)論,石墨烯的彈性性能具有尺寸相關(guān)性和手性相關(guān)性,尺寸對(duì)石墨烯的振動(dòng)特性影響比較明顯而手性對(duì)振動(dòng)特性的影響比較小。一定數(shù)量的單空位缺陷對(duì)石墨烯整體結(jié)構(gòu)的穩(wěn)定性影響較小,對(duì)楊氏模量和泊松比的影響基本呈線性關(guān)系,對(duì)振動(dòng)特性影響不大。空洞缺陷的尺寸對(duì)彈性性能和振動(dòng)特性都會(huì)產(chǎn)生一定的影響。裂紋的方向和長(zhǎng)度對(duì)石墨烯彈性性能的影響較大,裂紋的長(zhǎng)度和位置對(duì)石墨烯的振動(dòng)特性也會(huì)產(chǎn)生一定的影響。
[Abstract]:Graphene, which has excellent mechanical, electrical and thermal properties, has been widely studied by domestic and foreign scholars since it was discovered in 2004. Its unique properties are considered to be a new type of carbon material of strategic significance. The research of its mechanical properties is also a hot spot of mechanics scholars at home and abroad. Based on the theory of molecular structural mechanics, the elastic and vibration properties of graphene were studied by finite element method. Based on the equivalent relationship between the potential energy between atoms in molecular mechanics theory and the strain energy of beam in macroscopic structural mechanics theory, a circular section beam element which can simulate C-C covalent bond is established. The nonlinear relation of C-C bond is simulated by Morse potential function in molecular dynamics theory, and carbon atom is simulated by means of lumped mass element. The continuous medium model of graphene frame structure is established, and the finite element method is used to calculate and analyze the model. For the perfect graphene, the chiral graphene of armchair type and serrated type is studied, and the graphene of different aspect ratio and different size is studied in the aspect of dimension. For graphene containing defects, graphene with different number of vacancies, different sizes of cavity defects and cracks of different positions and lengths were studied. Based on the above different types of graphene, the elastic properties and vibration characteristics of graphene were studied. In terms of elastic properties, Young's modulus and Poisson's ratio are studied, and the first five natural frequencies and modes with fundamental frequency are studied. The main conclusions are as follows: the elastic properties of graphene have dimension correlation and chiral correlation. The effect of size on vibration characteristics of graphene is obvious, but chirality has little effect on vibration characteristic of graphene. A certain number of single vacancy defects have little effect on the stability of graphene structure, and have a linear relationship on Young's modulus and Poisson's ratio, but have little effect on the vibration characteristics. The size of cavity defects will have a certain effect on the elastic properties and vibration characteristics. The direction and length of crack have great influence on the elastic properties of graphene, and the length and position of crack will also affect the vibration characteristics of graphene.
【學(xué)位授予單位】：西安建筑科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：O613.71
，

本文編號(hào)：2039771