Jacob Moore

Fatigue properties of parts printed by PolyJet material jetting

Purpose – This paper aims to seek to fill a gap in the literature by characterizing the fatigue life and microstructure of a printed elastomer material, the TangoBlackPlus material. Design/methodology/approach – Because the TangoBlackPlus material is marketed as “rubber-like”, the printed elastomer specimens were tested according to the ASTM D4482-11 “Test Method for Rubber Property Extension Cycling Fatigue”. The microstructure of the printed material and multi-material interface was examined by slicing specimens and examining them under an optical microscope. Findings – Findings are developed to show the relationship between elongation and expected fatigue life. Findings also indicate that the smoother, non-support encased “glossy” surface finish option for PolyJet parts improve the fatigue life of components and that there are a number of microscopic voids in the TangoBlackPlus material that seem to be concentrated at layer and print head boundaries. Research limitations/implications – This paper provi...

Work in progress — A mixed-methods study of the effects of first-year project pedagogies on the motivation, retention, and career plans of women in engineering

Our research project compares two first-year engineering course project pedagogies to identify approaches that enhance the likelihood of women continuing in engineering majors and entering engineering careers. Specifically, we compare the problem-based learning (PBL) model to a more general experiential learning approach centered on the engineering design process, referred to here as the traditional engineering design model (TED). We hypothesize that the PBL model, with extensive faculty facilitation, will increase the likelihood of women persisting in an engineering degree, achieving higher grades in future classes, and going into engineering careers. Our research is grounded in motivational theory, and particularly in a model that integrates aspects of existing theories including participation-identification, expectancy-value, and self-efficacy. We are testing this integrated model and the research hypothesis through a longitudinal, mixed-method analysis, with data collected from five cohorts at two large research universities.

Targeted flipped classroom technique applied to a challenging topic

The significant initial time commitment to create online content required for flipped classrooms may pose an obstacle to their implementation, despite the known learning benefits. We hypothesize that flipping only specific, problematic topics may still provide benefits to students with less instructor preparation. In this study, we targeted a flipped classroom toward a single, difficult course unit (the Reynolds Transport Theorem in fluid mechanics) to reduce the total time required for course preparation. Six lectures on this topic were converted to online videos and in-class time was used for group-based problem solving. Comparisons were made between a traditional lecture section (n=8) and flipped classroom sections (n = 15). A statistically significant improvement was seen when comparing exam performance on a question-by-question basis. Student survey responses about the method were unanimously positive, and students specifically noted the ability to rewatch sections of the video as a benefit to their learning. The interview responses also produced an unanticipated result. Students indicated that they preferred the partial approach to a hypothetical full course flip, stating they felt “it would get old.” While the use of a targeted flipped classroom was investigated here to reduce the initial faculty time commitment, this finding may warrant future investigation on reaction to partial versus full course flipped classrooms.

Mastery grading of engineering homework assignments

In engineering courses, homework assignments are often intended to be formative assessments where students develop and refine their understanding of the subject material. In reality, however, homework assignments are often evaluated in a way that more closely matches a summative assessment, where the students have little incentive to reflect upon and refine their work. In this paper I discuss a mastery grading system designed to shift the focus of homework assignments from numerical grades to a focus on written feedback and reflection on that feedback. The paper presents the theoretical basis behind the methodology, outlines the mastery grading methodology itself, discusses the results of prior research with the mastery grading system, and presents new results from a two year study examining its effect on student learning, instructor time commitments required for implementation, and student opinions of the method.

Using Wikis as a Formative Assessment Tool for Student Engineering Design Teams

Due to its focus in project-based learning, design educators must provide individual coaching and mentoring of student teams as they progress through their design efforts. In order to increase the quantity and quality of design mentoring, the authors have implemented the use of Wiki websites as a medium for providing formative assessment for student design teams enrolled in a sophomore-level Mechanical Engineering design course. Wiki websites, which allow for easy creation and editing of interlinked webpages, were created for each design team in order to provide a virtual space for the creation, compilation, and editing of their design project report submissions. With access to each team’s Wiki site, the mentor is able to observe each team’s product design process unfold and provide feedback using an embedded commenting system. The public presentation of design reports also affords the facilitation of a peer-review of student work. In this paper the authors present details of the implementation of a Wiki for preliminary assessment data for this tool. Results show that the students found the tool and the associated activities to be easy to use, helpful in developing better design reports and a contributing factor to their development of critical and analytical thinking skills. In addition, students who used the tool reported receiving more meaningful formative feedback from the instructor and reported giving more formative feedback to their peers when compared to other sections of the class that were not using the Wiki.