Surface Stress Effects On The Dynamic Behavior Of Nanobeam Subjected To A Moving Oscillator

With the advent of nanomaterial, people began to keen on the exploration and research of nanometer materials. When the material size reduces to nanoscale, the surface atomic number relative to the internal atomic number will increase, which leads to the ratio of surface area of nanomaterials(the ratio of surface area and volume) increases and the surface atoms and internal atoms also has the huge potential difference. These properties make nanomaterials exhibit some properties which different from the macro-scopic size materials, such as:small size effect, surface effects, size-dependence and so on. The surface effects is one of the unique properties of nanomaterials, which greatly affects the mechanical properties of nanomaterials, is also an important aspect for the research of nanometer structure.Nanowire/beam is a kind of the most basic and common nanoelement. This thesis tries to based on the surface elasticity theory and the dynamic analysis of macrobeam subjected to moving oscillator to study the dynamic analysis of nanobeam subjected to moving oscillator in different beam theory. The specific contents are as follows:(1) Nanoscale Euler-Bernoulli beam and marcoscale Euler-Bernoulli beam have the different response when subjected to a moving oscillator.(2) Nanoscale Timoshenko beam and marcoscale Timoshenko beam and nanoscale Euler-Bernoulli beam have the different response when subjected to a moving oscillator.The results show that the dynamic response of nanobeam subjected to a moving oscillator depend not only on the theory of beam, the speed of nano-oscillator, the stiffness coefficient of nanospring and the nature of the material, but also on the surface effects. Es-pecially, the size-dependence phenomena of the nanosized is remarkable in nanoscale.