Experimental modal analysis for dynamic parameter identification

This summer during Research I learned a ton of skills that can be used in my field as well as many life skills that will be so useful for my professional life after college. My biggest takeaways from the project is I have a deep understanding of how to use Crystal Instruments Spider80XI software as well as SAP2000 software. These programs enabled me to gather actual data from our structure to use in comparisons and to visualize what is occurring in my cantilever experimental structure. I learned that 1-support cantilevers behave much differently than 2-support cantilevers especially when the 2nd support is hard to understand with what degrees of freedom it is truly restraining and I learned that structures don’t change very much from dynamic excitation over years and it is possible to reproduce results from many years earlier. I learned these through experimental analysis by moving support conditions around and altering the mass the electrodynamic excitation would send through the structure. Every change would have a substantial impact on the frequency the structure experienced in each mode. SAP was super helpful in this phase too because it enabled me to theoretically see when the frequency should be for each mode based on my configuration and can use that visualization to tweak my structure to be as close as possible to what is theoretically expected. When the two matched up closely I was able to determine my structure is acting how it would be expected.

Developing a low-cost turbidity sensor using synchronous detection

Turbidity is an essential measurement to assess water quality. Turbidity optically quantifies the cloudiness of a liquid and is commonly measured in Formazin Nephelometric Units (FNU). Commercial turbidity sensors are expensive, and previous work has developed numerous low-cost turbidity sensor designs. However, these designs face numerous challenges, causing inaccuracy in measurement, such as ambient light and bubbles in the liquid. This research developed an improved low-cost turbidity sensor that lessens the error caused by these challenges by adapting a colorimeter evaluation board, equipped with an analog-to-digital converter that reads the raw voltage output from a photodiode. The lock-in amplifier minimizes the effect of ambient light on the turbidity measurement by differentiating the light emitted from the LED and any ambient light. In lab tests, the developed continuous turbidity sensor was within 0.4 FNU from the actual turbidity more than 80% of the time, and nearly all of the readings fell within 1 FNU from the actual turbidity. Furthermore, analysis of the collected data revealed that the model can be accurately calibrated from only two distant turbidity measurements.

Investigations into the compressive behavior of a Miura-ori folded structure

Structural origami is an emerging field that combines the Japanese art of paper folding known as origami with structural engineering in order to assess the structures that can be created and their enhanced properties, such as compressive capacity and deformation pattern. Using an origami fold known as Miura-ori, a series of geometrical models were created representing three different angles along with two different thicknesses of the thin walls. The specimens were printed using plastic material called Polylactic Acid (PLA). A testing jig was designed and fabricated for the origami specimens to model a boundary condition with no translation during testing. The resulting deformation from compression testing appeared to follow a relatively consistent pattern of buckling, with some cracking and splitting happening on one edge. The specimens with a shallower angle could withstand less load. This correlates with elastic buckling theory as the height and width of the plates in these specimens are greater, and larger plates will buckle at a lower load. Further testing is needed to ensure the repeatability of these results. In addition, future research is needed to consider the deformation behavior of the individual plates to confirm whether the failure mode is buckling or a combination of crushing and buckling.

Developing an Assistive Technology to Support Effective Note-Taking Skills

Many students utilized note-taking strategies to record information for classes. Studies have shown effective note-taking techniques are critical for all students’ academic performance. The purpose of this research study is to investigate note-taking support for college students with Learning Disabilities (LDs) and English Language Learners (ELLs) by answering these three research questions: (1) What types of note-taking support are available for college students with LDs and ELLs? (2) What are the strengths and limitations of currently available note-taking support? (3) How can currently available note-taking support be improved for college students with LDs and ELLs? This study employed qualitative and quantitative methods. Surveys and interviews were conducted to find out the strengths and weaknesses of current note-taking support at various institutions.