Boundary Effects on Bridging-Stress/Crack-Opening Relationship and Specific Fracture Energy

本计画主要研究复合材料及薄层结构沿着裂纹路径至自由边界及双材料界面时，边界/界面对断裂/材料性质的影响。 着重研究了裂纹沿着路径的局部断裂能量耗散，并利用它研究了边界对粘聚规律的影响--裂纹桥联应力与裂纹张开位移的关系。提出了一种新的断裂力学模型，该模型综合了边界/界面影响和更流行的尺寸效应。 新的边界/界面效应模型将更适合于现代材料应用，如电子和生物医学应用中的层状陶瓷、薄膜、涂层。

This project is to investigate the boundary/interface influence on fracture/material properties of composites and thin layered structures along crack path to free boundary and bi-material interface. The local fracture energy dissipation along crack path is emphasised and used to study the boundary influence on the cohesive law - the relationship between crack bridging stress and crack opening displacement. New fracture mechanics model is proposed that incorporates the boundary/interface influence and the more popular size effect. The new boundary/interface effect model will be more relevant to modern materials applications related to layered ceramics, thin films, coatings in electronic and bio-medical applications.