My research interests include: computational solid mechanics, finite element method, design of new materials, multi-scale modeling, biological materials, micro-mechanics, fracture/failure of materials, fabric and composite modeling, ballistic impact, and contact mechanics. Below are descriptions of several of my current projects. Although I have experience with commercial simulation packages, the majority of this work has been done using my personal research codes. BALLISTIC SHIELDING Structural fabrics such as Kevlar and Zylon are popular choices for ballistic shielding due to their flexiblity and high strength-to-weight ratios. In addition to protecting personnel, these materials have been integrated into vehicles and structures. Ever since the crash of United Flight 232 in July 1989 near Sioux City, Iowa the FAA and the airline manufacturers have been concerned with protecting the flight critical components of the aircraft in the event of a rotorburst. Boeing, the FAA, and UC Berkeley teamed up to examine various shielding options. This project entailed a mix of simulation and experimental testing. For a more detailed look at this project, please click on the link below. Ballistic Impact of Structural Fabric BIOLOGICAL MATERIALS Biological materials present a number of interesting modeling challenges. These materials can respond to external stimuli by reorganizing themselves at the micro-level. The cardiovascular system is of particular interest due to its importance to daily life. In addition, many of the major ailments are associated with mechanical changes such as an increase in internal pressure (hypertension), a hardening of the material (atherosclerosis), and changes in geometry with a weakening/failure of the walls (aneurysm). Mechanical engineering and computational models can play an important part in understanding how these diseases affect the performance of the cardiovascular system as well as helping to evaluate and improve medical intervention. For a more detailed look at this project, please click on the link below. Modeling of Fibrious Biological Material