Free Vibration Of Carbon Nanotube-based Covalent Networks

Carbon nanotube-based covalent networks have attracted great interests from plenty of fields for its specific property,such as low mass density,high specific surface area and continuous porosity.It has been found that the carbon nanotube-based covalent networks possess the characteristic of good stability and electrical capacity,and high strength to create brand-new transistor and mass or strain sensor.Hence,it is very important to know the vibration performance of the carbon nanotube-based covalent networks to put into practice.The most representative structures of the carbon nanotube-based covalent networks are super-graphene and super-square.The molecular structural mechanics models and the coarse grained models of two kinds of structures are built,respectively.The main contents of the research on free vibration of these models with all boundaries clamped supported are as follows.Firstly,C-C bond is considered as Euler-Bernoulli beam and Timoshenko beam via molecular structural mechanics method.Afterwards,a single-walled carbon nanotube is considered to be a cylinder beam with uniformly distributed mass.The parameters of the equivalent Euler-Bernoulli beam and Timoshenko beam are calculated.The molecular structural mechanics models and the coarse grained models of super-graphene and super-square are built.The vibration frequencies of super-graphene and super-square with different side lengths,or different diameters,lengths of the carbon nanotubes are obtained.Meanwhile,vibration under tensile strain is also calculated.The natural frequencies and the associated mode shapes of the carbon nanotube-based covalent networks with all boundaries clamped supported are obtained.In comparison with the results obtained by the molecular structural mechanics method,the coarse-grained model accurately predicts the vibration of the carbon nanotube-based covalent networks.Moreover,the first twenty natural frequencies are calculated to discuss the high order vibration problem.