湿热环境下复合材料基体裂纹-夹杂相互作用机理的实验研究

The failure mechanism, deformation at the crack tip and the evolution of stress intensity factor of matrix crack-inclusion interaction under hygrothermal condition were investigated systematically by experimental and theoretical method in this project. First, a theoretical model about the matrix crack-inclusion interaction was established based on the Esheby equivalent inclusion method, which has considered the effect of hygrothermal condition, the relation between the crack-inclusion interaction and the temperature field, humidity field and stress field was obtained, and the effect of thermal expansion mismatch, humidity expansion mismatch on the matrix crack-inclusion interaction was analyzed. Then, non-contact optical measurement platforms of crack-inclusion interaction under hygrothermal condition were constructed, which is used to characterize the deformation at crack tip using digital image correlation method and characterize stress intensity factor using caustics. Finally, numerical technique was used to verify the reliability of the theoretical and experimental results of the matrix crack-inclusion interaction. It is expected to obtain some innovative research results, which will give guidance for the design, manufacture and engineering application of composite materials.

复合材料由于力学性能优异，广泛应用于航天航空等领域。湿热环境是其典型的服役环境之一，该环境下复合材料的断裂力学问题一直是研究的重难点。本项目针对湿热环境下的基体裂纹与夹杂相互作用失效机理、裂纹尖端变形特征及应力强度因子演化规律进行系统的实验研究与理论分析。首先，自主搭建湿热环境下复合材料基体裂纹-夹杂相互作用光学非接触实验测试平台，运用数字图像相关、焦散线等方法表征裂纹尖端变形特征和裂尖应力强度因子演化。其次，基于Esheby等效夹杂理论，考虑温湿度影响，建立湿热环境下基体裂纹-夹杂相互作用理论模型，揭示温度、湿度、静动态载荷与裂纹-夹杂相互作用之间的作用机理。本项目期望在理论和实验表征方面获得原创性成果，为湿热环境下复合材料止裂等重要工程问题提供理论支撑。

复合材料由于力学性能优异，广泛应用于航天航空等领域。湿热环境是其典型的服役环境之一，该环境下复合材料的断裂力学问题一直是研究的重难点。本项目针对湿热环境下的基体裂纹与夹杂相互作用失效机理、裂纹尖端变形特征及应力强度因子演化规律进行系统的实验研究与理论分析。首先，自主搭建湿热环境下复合材料基体裂纹-夹杂相互作用光学非接触实验测试平台，运用数字图像相关、焦散线等方法表征裂纹尖端变形特征和裂尖应力强度因子演化。其次，基于Esheby等效夹杂理论，考虑温湿度影响，建立湿热环境下基体裂纹-夹杂相互作用理论模型，揭示温度、湿度、静动态载荷与裂纹-夹杂相互作用之间的作用机理。本项目期望在理论和实验表征方面获得原创性成果，为湿热环境下复合材料止裂等重要工程问题提供理论支撑。