Reinforced Plastic Construction Methods for Large Rocket Motor Case. Volume V. Mandrels

摘要

Mandrels have been developed during this program for rocket motor use in R and D or in production programs. The mandrel design must be selected to accent flexibility of tooling for changes in case design, or to accent durability in repeated use, for economy in case production. Mandrel cost, weight, performance, and reliability must also be considered. A plaster or a plaster-shell-over-plywood construction readily permits changes in dome contours or case wall diameters. A cast mandrel of sand and resin, or a mandrel having extruded aluminum segments, required a low capital outlay and permits high case production rates if the case configuration is fixed. The sand-resin mandrel is relatively heavy among the five designs used. The dimensional stability and the light weight of the extruded mandrel are positive assets for fabrication of fiberglass cases larger than 60 in. dia but certain factors are not clearly defined (the reliabiltiy of its unique pressurization system and the potentially variable tension on glass fibers wound over aluminum). (Author)