Elastodynamic Analysis And Simulation Of Functionally Graded Carbon Nanotubes Reinforced Composite Plates

Because of the development of human society,the continuous development of land resources makes the shortage of resources and other phenomena.With the progress of science and technology,human gradually explore the marine resources,and gradually the development of the ocean is also increasing.We all know that the deep sea manned submersible is an important tool for mankind to explore the ocean,and its status in the ocean development process irreplaceable.When the deep sea submersible again and again are in the challenge of the limit and continue to create the "depth of China",deep sea manned submersible structure.Except the pressure shell,there is an non-pressure shell structure exists,that is light Shell.In the process of its pre-experimental and the end of the process of recovery,and withstand the impact of wave action in the water,even in the operation is not appropriate and harsh sea conditions and it may be a collision with the mother ship to the situation,these are easy to be in a dangerous state of force.Therefore,the requirements of the light shell to withstand a certain intensity of the impact.The production of the light shell generally is the glass fiber reinforced plastic and its composition that is made of synthetic resin as the base material,glass fiber or its products as a reinforcing material of a composite material.But because of its low elastic modulus,that makes the material structure under the load of a large rigidity so that it is easy to deformation or fracture and the low interlayer shear strength is easy to make the material layer is destroyed.These will be an important factor affecting the depth of the deep sea manned submersible and the safety performance.Carbon nanomaterials as a new type of material,in which the carbon nanotubes are physically and chemically superior in performance,have been considered ideal composites for composites.So the carbon nanotubes as a reinforced material join into the glass steel made of light shell matrix material can be fused very well.As the important parameter of the mechanical properties of carbon nanotubes,the Young's modulus is 0.15-4.84 TPa and the interlaminar shear strength is up to 500 MPa.According to the characteristics of these carbon nanotubes,it is found that it has excellent physical and chemical performance,therefore,it is considered to be the ideal enhancement phase for composites.Because the functionally graded material is excellent in functionality and novel in design,the enhancement effect can be maximized.The distribution of carbon nanotubes in functional gradient composites is divided into uniform distribution UD and three kinds of functional graded distributions O-type FG-O,V-type FG-V and X-type FG-X.In this paper,we mainly study three kinds of distribution UD,FG-O and FG-X.The problem domain of element-free method is replaced by a series of arbitrary distribution nodes,which do not need cell or grid to interpolate field variables,nor do we need to describe the relationship between nodes,the computation and the boundary condition are simple.There are many ways to form a meshless approximation function,in which the moving least squares method has been widely used.Due to the limitations of the moving least squares method,the IMLS-Ritz method is used to construct the trial function,and the calculation accuracy is higher and the stability is better.The Newmark-? method is used to perform numerical time integration of dynamic problems.In order to verify the accuracy and stability of the approximation method in this paper,the simulation results first compare the rigidity of the front and rear plates of the carbon nanotubes,and use the different scale points of the isotropic square plates and different scaling factors to verify the convergence.The results of this method are compared with others,and the error is within a certain range,then the method has good accuracy and stability.This paper focuses on the response of the carbon nanotube-reinforced FRP plate to the centre displacement of dynamic response with time-dependent subjected to transverse sudden dynamic load based on the first order shear deformation theory(FSDT).The meshless improved moving least squares(IMLS)method is extended to the numerical simulation.In this paper,the IMLS-Ritz method is used to construct the test function.In order to verify the effect of carbon nanotubes on the stiffness more intuitively,the dynamic response behavior of the materials before and after the addition of carbon nanotubes is studied.The elastodynamic of different quadrilateral and four kinds of regular polygonal carbon nanotubes reinforced composites with different volume fraction,different carbon nanotube distribution,different shapes,different plate thickness ratio,different boundary conditions and so on were analyzed.