Requirements and Constraints for a Robotized Roll Hemming Solution
The objective of this study is the design of a new roller hemming tool. For this purpose, main parameters affecting the final quality of the rolled hemmed part have been studied in order to identify and outline the key factors in roller design as well as in roller hemming process stages. A preliminary set of experiments has been carried out to study the pre-hemming force and springback relation in an aluminium sheet. Experiments showed the required forces in first pre-hemming stage and allowed to calculate a stiffness coefficient based on the springback deformation angle.
Improvement of hem quality by optimizing flanging and pre-hemming operations using computer aided die design
Abstract Flanging and hemming of straight edge-flat surface (plane strain) aluminum killed-draw quality steel was investigated restricting the study to the radius flat hem with an inner sheet. The major process parameters in straight edge hemming were determined and relations between them and some forming defects were established. Among these parameters were flanging die corner radius, pre-hem path, pre-hem stroke and final hemming force. Possible process and tool design modifications, which may lead to quality improvements in hemming were tested experimentally and using FEM. The commercial finite element program DEFORM was used to simulate the flanging and hemming operations including springback, and the predictions were compared with limited experimental results. Results of the experiments and simulations were summarized in the form of trend-lines for the use of process and die designers.
Just Wars: From Cicero to Iraq
Preface and Acknowledgements. Introduction -. PART I: MAPPING THE JUST WAR TRADITION. Chapter 1: Antiquity -. Chapter 2: The Middle Ages -. Chapter 3: Renaissance and Reformation -. Chapter 4: From Holy War to Enlightenment -. Chapter 5: Modernity and Beyond -. PART II: CONTEMPORARY ISSUES. Chapter 6: The Just War Tradition Today -. Chapter 7: Terrorism -. Chapter 8: Pre-emption -. Chapter 9: Aerial Bombing -. Chapter 10: Humanitarian Intervention -. Conclusion. Bibliography -. Index