Flexible Case -Grain Interaction in Ballistic Weapon Systems. Volume I. Technical Accomplishments.

摘要

The original objective of this program was to establish the reliability of existing structural analysis techniques for the prediction of stresses and strains in solid propellant grains. This was to be accomplished by fully instrumenting a full-scale Minuteman III Stage III motor with the latest stress-strain instrumentation, subjecting it to various test conditions (Thermal cycling, handling, vibration, pressurization) and then comparing the experimental results with predicted values. This was to be a 'closed envelope' approach in which the reduced data from the gages were to be kept secret until the final assessment phase of the program. The revised program included diagnostic evaluations to isolate error sources, a system rework to correct and/or modify questionable components, a parallel laboratory investigation of specific gage characteristics and, finally, verification of the stability of the reworked system. From the results of the diagnostic tests it was determined that the major anomalies observed could be traced to the gages-lead-wire-solder junction combinations. Use of an acid flux in soldering the stainless steel leadwires provided a potential for corrosion to occur as the junction aged. The reworked system which included crimped spade-lug junctions in place of the leadwire solder joints, a new DAS and revised operational procedures showed a substantial improvement in system stability, exhibiting an average drift rate of 0.5% of full scale output per month.