Civil Engineering Graduate Seminar, Thursday, September 12, 2013, Room 641 Dow
4pm to 5pm
Speaker: Dr. Zhen Liu, assistant professor of civil engineering, MTU
Title of Presentation: “Modeling the Multiphysical Phenomena in Porous Materials”
Porous materials (geomaterials, cementitious materials, etc.) are among the most abundant engineering materials that serve different disciplines. A thorough understanding of their behaviors is challenged by their susceptibilities to multiphysical processes as the result of their porous nature. Further advancements in porous materials research call for holistic multiphysics models and innovative characterization techniques. This study
investigated the multiphysical phenomena in three different types of porous materials (i.e., soil freezing, cement hydration, and dissociation of methane hydrate) based on their common features. Theoretical frameworks were first developed to couple the thermal, hydraulic and mechanical fields. Thermo-hydro-mechanical models were implemented using the finite element method. The simulation results cast light on engineering applications such as the safety and sustainability of pavement and buried pipes, the hydrating mechanisms of cement-based materials, and the recovery of gas hydrates. On the other hand, new instrumentation techniques were developed and utilized to characterize porous materials. These include a thermo-TDR sensor for the measurement of soil water characteristic curves, a modified capillary rise method for measuring apparent contact angles of soils, and an ultrasonic wave sensor-based method for measuring the pore-size distributions in concrete.