| The 21 st century is the era of deep ocean exploration and development.The large depth submersible as the important technical mean of achieving deep ocean exploration and development,its importance is more and more prominent.In order to meet the needs of deep ocean works,the material requirements for large depth submersible is corresponding increase.Based on the excellent physical properties,and mechanical properties of carbon nanotubes,it is recognized as the preferred enhanced phase of composite,which can improve the safety of the subsmersible operation.In this paper,carbon nanotubes reinforced composites as the object of study,respectively,the buckling and free vibration behaviors of the composites are studied in different conditions.The article mainly for the following three parts:1.Due to the problem of load transfer between the carbon nanotubes and the matrix material,there will be uncertainties about the effective material properties of composite.By applying Eshelby equivalent inclusions theory and Mori-Tanaka homogenization method and extended rule of mixture,the effective material properties of CNTRC are calculated,and the overall performance and response feedback of the material can be obtained concisely and conveniently.The improved moving least squares method is used to analyze the mechanical behaviors of CNTRC under different load conditions.2.The numerical study of CNTRC mechanical behavior is systematic work.The typical mechanical behavior of CNT-reinforced composite plates was studied by means of element-free method.In this paper,buckling behavior analysis of four different shapes of regular polygonal CNT-reinforced composite slabs id carried out.The critical buckling load and the center point displacement of the composite plates under different conditions were calculated by changing the thickness,the volume fraction of the carbon nanotubes and the applied boundary conditions of the CNT-reinforced composite plates,and corresponding buckling curves and three-dimensional fitting maps were drawn.3.Free vibration analysis is an important part of CNT-reinforced mechanical behavior research.In this paper,free vibration behavior analysis is carried out for three kinds of isosceles triangular CNT-reinforced composites with different vertex angles.According to the different in-plane stress ratio,the volume fraction of carbon nanotubes,the different boundary conditions,the distribution types of carbon nanotubes and the thickness of the composite sheet,the free vibration analysis of the composite plates were carried out and the influence of the geometric factors on the properties of the composites was analyzed.This study is helpful to provide practical reference for the practical study of the mechanical properties of CNT-reinforced composite.And provide theoretical support for whether the CNT-reinforced composite can meet the needs of the large depth ocean detectors in future application. |
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