Analytical model development and experimental investigation of process model size effects in microforming

With the emergence of micromanufacturing technologies, a critical need to develop process models that can accurately predict the required parameters, such as process forces, has arisen. As with the manufacturing processes themselves, macroscale process models can not effectively be used at the microscale due to size effects, i.e. changes in material and process parameters with miniaturization. Size effects with respect to material properties and frictional conditions have been demonstrated in past research. This dissertation demonstrates the existence of size effects due to process model assumptions and specimen deformation. The new models were evaluated by comparing the predicted results to both experimental and finite element simulation results. These new models showed significantly improved predictions of the peak forces for the microscale processes investigated. This is significant because sheet metal forming processes such as bending and extrusion are ideal fabrication techniques for mass production of parts at very competitive unit costs

Improvement of Spatial Ability Using Innovative Tools: Alternative View Screen and Physical Model RotatorR

Spatial ability, which is positively correlated with retention and achievement in engineering, mathematics, and science disciplines, has been shown to improve over the course of a Computer-Aided Design course or through targeted training. However, which type of training provides the most beneficial improvements to spatial ability and whether other means would be more effective, is not known. In this research project, two tools for use in spatial ability training were developed and evaluated. One tool, a Physical Model Rotator (PMR), rotates a physical model of an object in synchronous motion with a model of the same object in CAD software. The other training tool, the Alternative View Screen (AVS), provides the user of CAD software with both a solid model (including shading) and a line version view of the object. Students with poor spatial ability were identified through standardized testing and they were then trained over a four week period for one hour each week. The effectiveness of the training tools was evaluated by comparing spatial ability test scores before and after training. Results showed an increase did exist when targeted training was provided. However, this effect was not statistically significant, possibly due to the small sample size

Examining Industry Perspectives Related to Legacy Data and Technology Toolset Implementation

oai:ojs.edgj.org:article/6In this paper, results from a subset of the Purdue Spatial Visualization Test and a self-efficacy test developed by the authors are presented to determine whether certain object shapes, orientations, and types of rotations in standard spatial ability tests cause more difficulty than others and whether a solid object, which includes shading to distinguish different surfaces on the object, would have an effect on the spatial ability test results.  Lower spatial ability scores were observed for more complex object shapes, orientations, and number of rotations on both tests; however, viewing solid images as opposed to line images did not affect the spatial ability scores.  The subjects in this study were engineering students from various disciplines

Improvements in spatial ability as a result of targeted training and computer-aided design software use: analyses of object geometries and rotation types

Spatial ability, which affects retention and achievement in engineering and science disciplines, has been shown to improve through training and simply from enrollment in a Computer-Aided Design (CAD) course. However, detailed analyses of the specific object geometries and rotation types that cause difficulty for students on standardized spatial ability tests or which ones improve based on training has not been performed. This information may assist in determining the optimal training methods to improve the spatial ability skills of students and thus provide the most significant benefits for the training time committed. In this paper, scores from a standardized spatial ability test, which was administered before and after training and/or enrollment in a CAD course, are compared. The results show that the targeted training produced a significant improvement in the spatial ability test scores of students and that these improvements occur across,all object geometries and rotation types