复合材料点阵夹层结构的湿热老化性能研究

Composite sandwich panel with lattice truss cores possess broad prospects for application in high speed ship and submarine. However, hygrothermal environment has a significant effect on the properties of composite sandwich panel during their service life, and how to evaluate their hygrothermal properties has been a scientific problem needed to be solved by the mechanics and materials scientists. For this problem, optimized design of composite sandwich panel is performed in order to improve its hygrothermal properties, and the typical sandwich panel specimens are fabricated. The moisture absorption behaviors and mechanical properties of composite sandwich panel under hygrothermal environment are systematically studied by experimental tests, theoretical analysis and numerical simulation, then the moisture absorption characteristics of sandwich panel and moisture diffusion law in the structure are revealed. The theory forecasting model, damage evolution characterization method and failure criterion of mechanical properties of composite sandwich panel under hygrothermal environment are developed, and the effect of hygrothermal environment on the mechanical properties and failure modes of sandwich panel are analyzed. The hygrothermal ageing mechanisms of composite sandwich panel are revealed by dynamic mechanical analysis and scanning electronic microscope. This study can provide theoretical basis and scientific data on the design and life prediction of composite sandwich panel with lattice truss cores under hygrothermal environment, which can aid the engineering application of sandwich panel in ship structure.

复合材料点阵夹层结构在高速舰艇和潜艇等领域具有广泛的应用前景。点阵夹层结构在服役期间，湿热环境将对其性能产生重要影响，而其性能究竟如何成为当今力学和材料科研工作者亟需解决的科研难题。针对此问题，本项目以提高复合材料点阵夹层结构的湿热环境适应性为工程应用背景，对其进行优化设计，并制备典型的点阵夹层板试件。采用实验表征、理论分析和数值模拟相结合的方法，系统研究点阵夹层结构在湿热环境下的吸湿行为及力学性能，揭示该结构的吸湿特性及水分在结构内部的扩散规律，建立湿热环境下点阵夹层结构力学性能的理论预报模型、损伤演化表征方法和破坏准则，分析湿热环境对结构力学性能及破坏模式的影响。同时借助动态热分析仪和扫描电镜等先进设备揭示点阵夹层结构的湿热老化机理。本项目研究成果可为复合材料点阵夹层结构在湿热环境下的设计及寿命预测提供理论基础和科学依据，进而为促进其在舰船结构领域的应用奠定基础。

复合材料点阵夹层结构因具有高的比刚度、比强度及多功能特性，因而在高速舰艇和潜艇等领域具有广泛的应用前景。本项目以获得性能优异的新型复合材料点阵夹层结构为目标，对其进行优化设计，并采用模具热压法和真空辅助树脂传递成型工艺制备了典型的复合材料点阵夹层结构。采用实验表征、理论分析和数值模拟相结合的方法，研究了复合材料点阵夹层结构在室温环境下的力学行为和失效机理。同时开展了复合材料点阵夹层结构在不同温度环境下平压、弯曲和局部压陷力学行为的研究，分析了复合材料点阵夹层结构在不同温度环境下力学性能和失效行为的变化，得到了环境温度对复合材料点阵夹层结构力学性能和失效机理的影响规律。同时研究了复合材料点阵夹层结构在湿热环境下的吸湿行为及力学性能，得到了复合材料点阵夹层结构的吸湿特性及水分在结构内部的扩散规律，分析了湿热环境对复合材料点阵夹层结构力学性能及破坏模式的影响，揭示了复合材料点阵夹层结构的湿热老化机理。本项目研究成果可为复合材料点阵夹层结构的使用可靠性和安全性提供理论基础和科学依据，进而为促进其在舰船结构领域的应用奠定基础。