Experimental Mechanics

ME149 Mechanical Measurements, Stanford University

April 2019 - June 2019

I completed four projects with Stanford testing equipment and software to characterize material properties:

1) MTS Testing

Through uniaxial tension and 3-point bending tests, I produced stress-strain curves for various materials. The main aspects of the project involved calibration of a model 43 MTS tester and digital image correlation in Matlab. The end result was achieving the accuracy and precision required to characterize specific alloys of aluminum and steel.

2) Rheometry

With a basic parallel plate rheometer setup, I tested various samples of viscoelastic fluids with Newtonian, shear thickening, or shear thinning properties. These experiments included both fixed and oscillatory shear rates in which I determined yield points, elastic recovery, and storage modulus.

3) Cardiovascular Flow

I created a physical model to simulate the fluidic resistance and capacitance of systemic cardiovascular circulation. The full experimental setup included a pulsatile blood pump, flow and pressure sensors, an oscilloscope, and an elastic reservoir to act as the venous system. By converting the electric signals to fluidic measurements, I calculated the aortic pressure and distal artery flow waveform.

4) Vortex Ring Imaging

I used digital particle image velocimetry (DPIV) to identify the limit and growth rate of vortex ring circulation compared to its predicted behavior by N. Didden. By suspending particles in a 100-gallon water tank, I tracked laser-illuminated particle paths to define the vorticity vectors. The area integral over these vectors showed strong relationships to Didden’s theories for approximately 2 seconds before deviating into noise.