Henry Panganiban

Hybrid Full-Field Stress Analysis Around Holes in Tensile-Loaded Plates by Phase-Shifting Photoelasticity

A hybrid stress determination around circular and elliptical holes utilizing photoelastic phase-shifting and nonlinear least-squares methods is presented. The method was demonstrated by calculating fringe orders of distant points along straight lines using 8-step phase-shifting method. The data was used to evaluate the coefficients in the complex stress functions for hybrid analysis. Tangential stresses around the boundary of the holes were obtained using conformal mapping technique. Different number of terms in a power-series representation of the complex type stress function was tested to qualitatively observe the effects of varying stress field. Actual fringes were related with the reconstructed and sharpened fringes along with the change in the number of terms, m. Good agreement was obtained when m in stress functions was equal to nine. At high stress concentration, the result obtained from the hybrid method agrees with FEM by two and five percent for circular and elliptical hole, respectively. The results show that the established numericalexperimental method for stress analysis is considerably reliable.

Development of a Smart Residential Fire Protection System

Embedded system is applied for the development of smart residential fire detection and extinguishing system. Wireless communication capability is integrated into various fire sensors and alarm devices. The system activates the fire alarm to warn occupants, executes emergency and rescue calls to remote residents and fire-fighting facility in an intelligent way. The effective location of extra-sprinklers within the space of interest for the fire extinguishing system is also investigated. Actual fire test suggests that the developed wireless system for the smart residential fire protection system is reliable in terms of sensors and their communication linkage.

Automobile body continuous-variable-based discrete thickness optimization for maximizing natural frequency

Thickness optimization of an automobile body is presented. The thicknesses of plates making-up the monocoque body of an automobile are employed as design variables for optimization and the objective is to increase the first torsional and bending natural frequencies. By allotting one design variable to each plate of the body, compared to previous works based on element-wise design variables, design space of optimization was reduced to a large extent. Considering manufacturability of the optimized thicknesses, a straightforward thickness discretization scheme considering design sensitivities and employing a subsequent reduced optimization problem is formulated. With the optimized thicknesses, the car body maintained its weight with around 6 Hz frequency increase compared to the initial design.