Enhancing the Interfacial and Dynamic Failure Behavior of Advanced Hybrid Structures Using Nanocomposite Materials

摘要

A novel interfacial joint was developed for reducing the interfacial stress levels. The proposed design, inspired by the shape and mechanics of trees, effectively removed the stress singularity at the interfacial joint for most engineering materials through an integrated theoretical and experimental investigation. Significant tensile loading capacity increase was obtained (up to 81%) using this new joint, while the material volume of the new joint actually was reduced. Dynamic tension experiments showed that the new convex joint yielded an increase in final failure strength (22%). This new joint can be employed to accurately evaluate the interfacial strength improvement of dissimilar material joints. Nanofiber-reinforced epoxy bonding with linker molecules was synthesized and tested for metal/metal and polymer/polymer joints. Mechanical properties including tension and shear bonding strengths showed very low increase or even decrease of nanocomposite bonding over that of pure epoxy bonding.