Project lead

Duy Nguyen
​

Current project goals

1. Investigate the global in-plane rigid body rotation of the GSM utilizing Digital Image Correlation (DIC).
2. Determine vital parameters that significantly displace the GSM
• Determine velocity dependence 
          -At a constant plane, vary the velocity of the circular path to determine if they affect the rotation linearly
• Determine diameter dependence of inner region
          -At a constant plane, vary the diameter of the circular path to determine if they affect the rotation linearly
• Determine the depth dependence on the inner rotation
          - With constant needle velocity and diameter of the circular path, use the DIC at various planes to understand the displacement due to depth 
          - At a constant plane, vary the velocity and diameter of the circular path to determine if they affect the rotation linearly

Project Progress

​4/26/17
​We printed a speckle plane into a rectangular container and dragged a needle (0.71 mm) in a circle (Radius 10 mm) through carbomer 980 at a concentration of 0.125% while imaging from below. 

This video shows 55 circles in the clockwise direction, and then 55 circles anti-clockwise. We see that there is rigid body rotation of the plug within the closed path of the circle, and negligible deformation outside of the closed path. After all cycles have completed, there is an extra rotation of the plug. 

Ideas to try:
• what happens when we go forward and reverse every cycle.
• What happens with other shapes?
• Is there a depth dependence?
• Speed dependence?
• Diameter of circle?
​• Concentration dependence?

5/01/17
We kept the same parameters for the previous test, but slowed the velocity of the needle down to 0.1 mm/s ​

5/05/2017
Variation in velocity and radius. 

5/15/2017
Variation in depth

13.5 mm below the plane

1 mm below plane

1 mm above plane

7.25 mm below plane

On plane

5 mm above plane

Results of the analysis

Begin final set of experiments

In the final set of experiments, we will be doing all of the tests in a circular container, with the speckle pattern in the middle of the volume of carbomer. The following parameters will be varied: D = diameter of the circle, H=the height above or below the speckle plane, V=velocity of the needle. We will attempt to discover the deformation a speckle plane due to a needle of diameter d=0.71 mm in various conditions. The effect of needle depth on distortion of the inner plug will be found by looking at a side view of a line that is vertical at time t=0, and deformed into a spiral at time t=t. By identifying the depth away from the needle tip in which the line is still vertical, and the angle of twist above this point we can back out the magnitude of deformation continuously through the depth.  

7/11/2017

Concentration of Ashland 980 : 0.125 %
Needle Diameter : D=0.71 mm
Radius of circle : 5.6703*needle diameter
Velocity : 0.08201 mm/s
Depth : 0.4756 % below surface (0.5% is surface) 

The total Volume depth is : XXXXXXX

Using DIC to measure the deformation every 3 degrees of needle travel, we begin to see the cause of the rigid body rotation.

Next set of experiments