24 research outputs found
Thermal Investigations During The Plug Assisted Thermoforming of Homopolymer Polypropylene Sheet
Thermoforming Process Simulation for the Manufacture of Deep-Draw Plastic Food Packaging
The development of an effective and representative finite element-based simulation of the deep-draw plug-assisted thermoforming process is presented. It has been clearly demonstrated that the frictional and thermal effects of plug contact are of critical importance and appropriate relationships for these have been developed and included in the simulation. A constitutive material model based on the van der Waals strain energy function has been used to represent the deformation response of the high-impact polystyrene polymer sheet and the model parameters have been closely fitted to biaxial test data. The prototype simulation is stable and its output is generally in good agreement with experimental measurements. It is recognized that model accuracy could be improved further through additional experimental investigation of the process. The working simulation provides a powerful platform for in-depth analysis of the thermoforming process. </jats:p
Factors Which Influence The Academic Performance Of Level 7 Engineering Students
High module failure rates can lead to poor student retention and a need exists for improved understanding of the determinants to academic performance. This research examines the influence of a number of factors on academic performance among Level 7 Engineering students in Dundalk Institute of Technology over a four year period. Using statistical regression techniques age-group, attendance, marks available for continuous assessment, class-size, semester of study and year of study were investigated. Statistical evaluations based on a sample set of 1263 identified that mature students, students with positive levels of attendance and modules with high levels of continuous assessment marks appear to result in better performance. It is envisaged that this work will contribute significant data to the limited knowledge base in this area especially in terms of engineering education. Based on the findings of this study, it is recommended that continuous assessment activities, which take place during class time, be used to incentivise student attendance and engagement, which should lead to better academic performance
Understanding the Energy Requirements of Thermoforming with Continuous Fibre Reinforced Thermoplastic Materials
In this paper we study the replacement transformation for Constraint Logic Programming modules. We define new applicabihty conditions which guarantee the correctness of the operation also wrt module¿s composition: under this conditions, the original and the transformed modules have the same observable properties also when they are composed with other modules. Furthermore, the applicability y conditions are uot bound to a specific notion of observable. Here we consider three distinct such notions: two of them are operational and are based on the computed constraints; the third one is the algebraic one based on the least model. We show that our transformation method can be applied in any of these distinct contexts, thus providing a parametric approach