Konstruktion av formkropp pa JAS 39 E/F Gripen

Sammanfattning: The aim of this work is to develop new conceptual designs for the fairings that are situated between the fin and the rear fuselage on the new version of the JAS 39 Gripen aircraft, called the Gripen E/F. The designs presented should show a profit in the form of lower weight. To achieve weight loss, the possibilities of using other construction materials other than those which are available at Saab today were studied. Therefore, a material survey was carried out in which the market for modern construction materials was studied to get an idea of today’s level of technology. Furthermore, a procedure was performed to produce new designs, which in turn can be used to create new concepts. The new concepts are then evaluated by means of systematic concept development. This resulted in a total of four concepts for the left side fairing and two for the right. These were then evaluated carefully, and finally, an estimation of the weight was made for the different concepts to see how it related to the original concept. In analysis of the four concepts, it was found that the temperature differences in the structure constitute a much larger problem factor than the materials coefficient of thermal expansion. This resulted in the exclusion of one of the concepts. The right side was treated somewhat more briefly as it quickly became clear that the only thing that prevented from making the right side fairing according to the methods already used today for the Gripen C/D was cost, which was considered to be outside the scope of this report. Finally the three concepts for the left side fairing were compiled and it became clear that there were significant benefits to be made, in terms of reduced weight, if one were to investigate the possibility of approving new construction materials for use at Saab.