Centennial Campus
Research Building 3
Room 221
Phone: (919) 513-1006
 
 
 
 

Objectives

For the past four years, Profs. Banks, Fitzpatrick and Tran have developed modeling courses (MA573-574) based on fundamental physical processes: heat flow, wave propagation, fluid, population and structural dynamics, electromagnetic dispersion, and optics. A major innovative component of the course has been the exposure of students to specific laboratory experiments, data collection and analysis. As usual in such modeling courses, the pedagogy involves beginning with first principles in a physical, chemical or biological process and deriving quantitative models (partial differential equations with boundary conditions, initial conditions, etc.) in the context of a specific application such as thermal nondestructive damage detection in structures, active noise suppression in acoustic chambers, smart material (piezoceramic sensing and actuation) structures vibration suppression, and fluid transport in thin film vapor deposition reactors. The students then use the models (with appropriate computational software - some from MATLAB, some from routines the instructors have developed specifically for the course) to carry out simulations and analyze experimental data. The students are exposed to experimental design and data collection through laboratory demos in certain experiments and through actual hands-on experience in other experiments.

Our experience with this approach to teaching advanced mathematics with a strong laboratory experience has been, not surprisingly, overwhelmingly positive. Indeed, with support from NSF grant DUE 9751284, and Center for Research in Scientific Computation and Department of Mathematics thu cost sharing, we have developed our own teaching experimental laboratory. This laboratory provides capabilities for three distinct physical experiments: heat conduction, beam vibration, and acoustic wave propagation.
 
 

Experiments

Heat Conduction
 
 
 
 

This experiment is designed for heat transport studies in a rod. The surface temperature distribution of the rod which is heated at one end by a soldering iron is measured by fast response thermocouples. These thermocouples are inserted at multiple locations (15) on the rod. The temperature measurements are recorded in real time on a PC computer using a front-end analog multiplexer that quadruples the number of analog input signals. The analog signals are digitized by the MIO series multifunction DAQ boards. Copper and aluminum bars are available in the lab to study the properties of different metals and how do they affect the heat conduction.
 

 

Acoustic Wave Propagation
 
 
 
 

A PVC pipe is used to study the acoustic response of an enclosed sound field. A sound wave source is induced at one end of the PVC pipe through excitation of a commercial acoustic loudspeaker. The other end of the PVC pipe is used to study the effects of different types of boundary conditions (reflective, absorptive, semi-infinite axis, etc.) on the enclosed sound field. The acoustic response of the system is measured at various locations throughout the pipe by electnet condenser microphones. These sound level measurements are monitored in real time by an HP oscilloscope. In addition, a HP dynamic signal analyzer is used to record and analyze the measurement data. The dynamic analyzer is capable of providing both real time and frequency measurement.
 
 

Beam Vibration
 
 
 

In this experiment, modal analysis is performed on a cantilever beam in a "smart material" paradigm. One end of the beam is clamped while the other end is free and the beam is mounted with two self-sensing, self-actuating piezoceramic patches. The beam can be excited by two sources: (a) an impulse excitation  and (b) a periodic excitation (through piezoceramic actuators). The beam transverse acceleration is measured by accelerometers. In addition, the beam transverse displacement can also be measured by a proximity sensor (non-contacting) and by the piezoceramic sensors. Data are again recorded and analyzed with the HP dynamic signal analyzer.
 

Sample Projects

Heat Conduction
Beam Vibration Analysis