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Computing Across Curricula (CAC)The Final Report of Fellow Action Research Project

Fellow InformationName: Russell E. Gorga Position (Job Title): Associate Professor

Department: Textile Engineering, Chem,Sci

CAC Fellowship Year and Semester: Spring2009

Email: regorga@ncsu.edu Phone: 515-6553

Years Employed at NCSU: 6.5 Years of Teaching (Total): 7.5

Courses you teach (on average)Number of Fall Sections: Undergraduate Level ___2____ Graduate Level ______Number of Spring Sections: Undergraduate Level ___2____ Graduate Level ______

Project InformationAction Research Project Title: Computer modeling to solve the Zener viscoelastic model

Course InformationCourse Title: Polymer Engineering

Course Number: TE 463 Number of Students: 49

PURPOSE & OBJECTIVES

Purpose: To encourage students to use computer modeling to prove that two different forms ofthe Zener model for viscoelasticity are identical. In the past I have asked students to show(physically) that they perform identically. Here, I asked the students to both look at it physicallyand show mathematically (using a computer model) that they are identical.

Objective: 1) Show the two Zener models are identical (physically); 2) Show the two Zenermodels are identical mathematically (using a computer model); and 3) Provide feedback on bothparts 1 and 2 and comment on which was more useful for your understanding of theviscoelastic behavior.

METHOD

I provided both Zener models and the analytical solution to mathematically show that they areequivalent. I asked students to use whatever computer modeling software they were comfortablewith (half the class took a BME course which focused on Matlab and the other half took a TE coursewhich focused on Visual Basic with Excel). I presented the problem (as outlined above under“objectives” and gave the class 2 weeks for the assignment.

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RESULTS

I received very few inquiries for help, so I assumed that the assignment was straight forward. Theclass period before the due date, some students said they were unclear of what I was looking for,so I reiterated the objectives to the entire class.

Those that solved the problem using Matlab had very little trouble doing so. Those trying to useVisual Basic were unclear how to begin and what to do to solve the problem.

Overall, the results were rather straightforward (see table below), and the majority of the studentsfelt that physical understanding portion of the assignment was more helpful than the mathematicalportion. A rather significant number said they “didn’t get anything” out of the mathematical portionor that it was very confusing.

Feedback: Provide feedback on both parts 1 and 2 and comment on how each helped tocontributed to your understanding of viscoelastic behavior.

Here is an expert of some of the students’ comments:-Thought was helpful, would be nice to graph stress (strain) vs. time-Made me think about the models in two different ways to show they are the same-confusing, needed more explanation-took too long and not helpful for amount of time put into it-felt tacked on-exercise in futility-most of us are unfamiliar with Matlab/VBA-No organized direction-gave up in futility-you told us “not to get bogged down in the math”-I don’t know how to use Matlab-I don’t know Matlab and I swore I would never use VBA again after TE 110-I personally hate numbers

CONCLUSIONS

Overall, I think it was a good attempt to incorporate a computer modeling segment, but I needto do more work to make it more effective. Some of the “strong” students got it, but themajority of the students did not. I need to reach the majority population in the class. I willcontinue to do this exercise and will put effort into making it better.

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NEXT STEP/LESSONS LEARNED

I will provide more guidance and spend more time to lead the students through theprocess. Here, I will spend time to “lead them” through the analytical solution I provide(including some gaps that the students will need to fill).

I will also go through the solutions using both Matlab and VBA so that I can provide moredetailed guidance on how to solve the problem (and provide advice on how to avoid“time sinks”).

I will incorporate a suggestion from a student who suggested that they plot the stress (orstrain) as a function of time for both models (to further show the behavior is identical).

I will ask for more quantitative feedback on the exercise. Specifically, I will ask them torank the effectiveness and provide more specific feedback on learnings/obstacles.