Research On Mechanical Properties And Sound Insulation Of 3D Woven Hollow Integrated Sandwich Composites

The rapid developments in the fields of aviation,aerospace and construction propose higher requirements for the comprehensive performance of the materials.Material with the single advantage is difficult to meet the actual demand.Three dimensional(3D)woven hollow integrated sandwich composites is a new type of integrated woven sandwich structure material,which combines excellent performance of woven fabric and sandwich structure,will be widely applied in future.This thesis focuses on the research of the mechanical and sound insulation properties of 3D woven hollow integrated sandwich composites in order to provide theoretical basis for the popularization and application of this material.The main contents are as follows:(1)Based on the meso structure characteristics of 3D woven hollow integrated sandwich composites,the double-rhombus shaped core model is established to study the mechanical properties under edgewise tensile,edgewise compressive,flatwise compressive,shear and bending loads,respectively.The accuracy and rationality of the models are verified by compared the predicted data with experimental results.On this basis,graphical interface,which integrates the above theoretical algorithms,and runs on MATLAB platform,is developed to research the influence of weaving process parameters on mechanical performance.(2)According to the mechanical characteristics of 3D woven hollow integrated sandwich composites under different working conditions and the double-rhombus core model,microstructure geometrical model with different sizes are built.The progressive damage and buckling analysis methods are introduced in numerical simulations to study the stiffness,strength and microscopic failure mechanism.Besides,the experimental study provides verification and supplement for the simulations.(3)Based on the study of mechanical properties,the finite element model for analyzing the sound insulation of 3D woven hollow integrated sandwich composites is constructed to calculate the sound insulation property.The influence of system parameters including pitch angle of incident sound,the layer number,in-plane dimension and constraint condition on the sound insulation performance is discussed.