Raquel Paramo ’17 presents at Steinmetz on speckles


On Friday, May 12, over 500 students woke up to present their research to not only the campus community, but those who visited as well. From English to Biology, and from Africana Studies to Chemistry, no project was small enough to be presented. One such project, a presentation that could be found in what some students might call the epicenter of Engineering (N205), was presented by a Raquel Paramo ‘17. Her summer research, entitled “Optimizing Speckle Patterns for the Digital Correlation System”, attempted to further understand and advance the optimal speckle size on a given object in order to properly use the optical material characterization technique called Digital Imagining Correlation. The system, as Paramo explained, correlates visual speckle distortion to the tensile strength, elasticity, etc. of a given object. As an object is coated in a random pattern of speckles, the digital imaging system tracks said speckles and their shape as forces are applied. Once the speckles change shape, an algorithm converts the data into information about the object’s bulk mechanical properties. The system in question is called ARAMIS 2M. The research goal, as stated by Paramo, was to create the optimal patterns through a standardized technique, i.e. with the use of ARAMIS 2M. Identified through previously conducted research, the ideal speckle size for the camera was between three to five pixels, with a grayscale ideal of fifty percent black and fifty percent white. Testing parameters such as pressure, distance, paint to thinner ratio and orifice opening, Paramo created the targets (objects), calibrated the system recorded fields of view, observed targets under the optical microscope, determined size of speckles, captured targets on the DIC system and used MATLAB to perform grayscale analysis. Over and over the procedure was repeated, data was collected and certain patterns were discarded. At the conclusion of the study, it was determined that the most important parameters were constant pressure and distance. At 20 psi and 50×40 magnification, the average optimal speckle size was 4.4 pixels, as theorized. Upon finishing, multiple questions regarding the need for further research was questioned, since the determination of appropriate speckle sizes is difficult. As this is the case, when asked what she herself thought of her research and what she found most satisfying, she said, “I got to work closely with my professors and build a mentoring relationship with them. More importantly however, I had the opportunity to make an impact on the scientific community.”


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