• Numerical simulation of thermo-mechanical behavior of gypsum board wall assembly

      Quan, Zhili; Hulsey, J. Leroy; Ahn, Il Sang; Chen, Cheng-fu; Xiang, Yujiang (2019-05)
      Fire safety has become a significant concern to public safety; especially in the aftermath of 9/11 attack where, according to official reports, three World Trade Center buildings collapsed because of fire. Therefore, the level of thermal insulation required from building material and structural elements has increased. In recent years, gypsum board wall assemblies have been increasingly used as compartmentation for high-rise residential and commercial buildings. The increasing popularity of gypsum board wall assemblies is due to their relatively high strength-to-weight ratio, ease of prefabrication, fast erection and good thermal insulation. Before implementation of any building material or structural element, its Fire Resistance Rating must be determined by subjecting the material or element to a standard furnace fire test. Over the years, a large database has been collected for the Fire Resistance Rating of building materials and structural elements. However, due to the expensive and time-consuming nature of the standard fire tests, determining an accurate Fire Resistance Rating can be a difficult task. In this study, the author numerically evaluated the Fire Resistance Rating of a new gypsum board wall assembly. Composite steel-EPS (Expanded Polystyrene) insulation is added to a traditional gypsum board wall assembly. The author first did numerical simulation of an experiment on the thermal response of a non-load-bearing gypsum board wall assembly to verify the thermal modeling methodology. The author then did numerical simulation of an experiment on the mechanical response of a load-bearing gypsum board wall assembly to verify the mechanical modeling methodology. Finally, the author used the verified thermal and structural modeling methodology to simulate the new composite steel-EPS gypsum board wall assembly and obtained its numerical Fire Resistance Rating. This Fire Resistance Rating should be compared with future experimental results of the new wall assembly. All modeling was done with ABAQUS V6.14.
    • Response of pile-guided floats subjected to dynamic loading

      Quan, Zhili; 权致力; Chen, Gang; Metzger, Andrew; Hulsey, Leroy (2013-12)
      Pile-guided floats can be a desirable alternative to stationary berthing structures. Both floats and guide piles are subjected to time varying (dynamic) forces such as wind-generated waves and impacts from vessels. There is little design information available concerning the dynamic load environment to which the floats will be subjected. So far, the most widely acceptable method used in offshore structure design is the Kinetic Energy Method (KEM). It is a simplified method that is based on the conservation of energy. This approach is straightforward and easy to implement. However, in spite of its simplicity and straightforwardness, the method lacks accuracy. The intent of this project is to develop a rational basis for estimating the dynamic response of floating pile-guided structures, providing necessary insight into design requirements of the guide-piles. In this study, the Dynamic Analysis Method (DAM) will be used to model the dynamic responses of the system. MATLAB codes are written to help calculate the analytic and numerical values obtained from the dynamic models. For the purpose of validation, results from the two systems should be compared to a comprehensive dynamic analysis model created with the ANSYS AQWA Software.