DIE

Optimization of process parameters in sheet metal forming is an important task to reduce manufacturing cost. To determine the optimum values of the process parameters, it is essential to find their influence on the deformation behaviour of the sheet metal. The significance of three important process parameters namely, die radius, blank holder force and friction coefficient on the deep-drawing characteristics of a stainless steel axi-symmetric cup was determined. Finite element method combined with Taguchi technique form a refined predictive tool to determine the influence of forming process parameters. The Taguchi method was employed to identify the relative influence of each process parameter considered in this study. A reduced set of finite element simulations were carried out as per the Taguchi orthogonal array. Based on the predicted thickness distribution of the deep drawn circular cup and analysis of variance test, it is evident that die radius has the greatest influence on the deep drawing of stainless steel blank sheet followed by the blank holder force and the friction coefficient. Further, it is shown that a blank holder force application and local lubrication scheme improved the quality of the formed part.

Expansion and reduction are the two common end forming processes for tubes. In the tube end expansion process using a square punch, it is difficult to obtain a small corner radii due to the stretching of the tube around the punch corners. The wall thickness around the corners is small when compared to the side wall. Hence, a tube having a poor square look is formed. In this study, a 2-stage end expansion of a round tube end into a square section having an improved square look i.e. small corner radii and increase in wall thickness around corners is developed. In the 1st stage, the tube end is flared into a cone shape using a 30 conical die by axial compression. In the 2nd stage, the conical end of the tube is drawn through a taper square die using a conical bottom square punch, and a near square section is formed. A 15% ironing ratio is applied during the drawing process to flatten the side wall of the square. Experimental and FEM simulation were performed to evaluate and to verify the forming process. Although the height of the square section increases when the punch stroke at the 1st stage is increased. However, this increase is limited by the buckling of the pipe at the circular section of the thick blank tube. Since the conical end is drawn into a square section having different radial lengths, the bottom of the square section is uneven. The uneven bottom end is trimmed off in the later process. A square section having a maximum height of 32 mm after trimming is successfully obtained from the experiment for the punch stroke, S=44 mm using an API 5 L tube. (C) 2013 Elsevier B.V. All rights reserved.

http://www.sciencedirect.com/science/article/pii/S092401361300112X

The current dissertation is based on an action research and case study scheme performed in two Greek schools of Secondary Education, namely the 7th Gymnasium and 5th Lyceum of Kavala, with the purpose of investigating how students’ motivation to learn English may be enhanced and linguistic skills practiced through Theater and Drama practices. In this context, the Greek educational context is presented and motivational parameters influencing Foreign Language Learning of adolescents are explained. Special focus is given to motivation through Applied Drama projects in schools and, thus, the practices of Drama in Education (DIE) and Theater in Education (TIE) are theoretically portrayed. The entire study involves the process of upstaging a musical in the English language, namely the preparatory stage, the rehearsals and the performances, along with an innovative teaching-via-theater scheme, exercised by the stakeholders involved. Hence, a combination of process and product-oriented practices are utilized to achieve maximum results concerning motivation and practice of linguistic skills of the participating students. The research conducted is grounded on three research questions which examine: i) the emotions instilled in EFL students during the process, ii) the extent to which the project may influence students’ motivation and language practice and iii) the potential benefits gained. This study is an outcome of methodological triangulation, incorporating both qualitative and quantitative research methods. As such, the educator’s personal log, interviews, videos throughout the process and recorded conversations in social media platforms enabled qualitative extraction of findings, whereas observations from colleagues, and answers to questionnaires provided to the students/actors and the audience of all TIE-DIE phases enriched quantitative analysis of the provided data. As will be exhibited in the dissertation, language skills concerning learning English have been practiced, students’ motivational stance has been enhanced owing to a plethora of positive emotions experienced in the process and a positive attitude towards Drama practices in an educational context has been developed. However, owing to the fact that this study is only a limited investigation of this crucial topic of research, the researcher fervently suggests that similar inquiries should take place in Greek schools, with the aim of recording further results and potentially incorporating such practices in the school curricula.