Micro-mechanics of imperfect interface between dissimilar materials with micro-structures

• Main Author: Liu, Yuquan
• Other Authors: Fan Hui
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/171174
• Institution: Nanyang Technological University

The present study investigates three distinct types of imperfect interfaces between dissimilar materials, each exhibiting unique micro-structures. The first type of interface is characterized by evenly distributed micro-cracks and is modeled as spring-like. The effective property stiffness of this interface, denoted by K, is evaluated through the use of Finite Element Method (FEM), Self-Consistent Method (SCM), and analytical solution techniques. The analytical solution uncovers an equivalence relation between stiffness K and energy release rate of cracks, providing insights into the behavior of the interface damaged by micro-cracks. The second type of interface is wavy in nature and is modeled as a membrane-like inter-phase. Due to the complexity of boundary conditions of the anti-plane problem, we utilize displacement periodic boundary conditions(PBC) to simplify this problem. To address the geometry singularity problem that arises in SCM, we adopt a high-order self-consistent method to mitigate its influence. Lastly, the third type of interface is characterized by a combination of wavy interface and micro-cracks distributed within the waves. To analyze this interface, a serial model comprising both spring-like and membrane-like components is proposed, and the effective properties of this model are computed at varying combinations of micro-cracks and microwaves. The findings indicate a mutual influence between micro-cracks and micro-waviness, underscoring the importance of considering both factors in the modeling of such interfaces.