Fracture, friction and granular simulation

This thesis contains three separate yet closely related topics: fracture, friction and simulation of mechanical response of a confined granular medium. The first two are experimental investigations and the last one is a numerical study. In the fracture part, I will describe how to break a piece of silicon in a controlled way such that the atomic nature of the fracture process can be revealed in a macroscopic experiment. In the friction part, I will present another experiment using almost exactly the same setup as for the low temperature fracture experiment to study the properties of static friction and explore ideas concerning the origin of friction. In the last part, I will construct a confined granular packing and study how pulses and continuous waves propagate through it. All these three topics are relevant to geophysical science. I sincerely hope that my study can ignite some fresh thinking in that area and help other researchers to design models that can make more precise earthquake predictions.