Assessment of the propensity for spark generation during normal operation of the H1571 tilted spring stand.

摘要

An investigation was conducted to assess the propensity for spark generation as a result of impact contact between metallic materials. This study was motivated by the desire to determine whether or not incendiary sparking has occurred during routine operation of the H1571 tilted spring stand. Spark generation presents a hazard because of the potentially ignitable matter that is discharged from the payload package of the H1571 during normal functioning. Testing of various material combinations under different impact conditions was not performed explicitly in order to obtain spark generation information for the H1571; rather, the results of previous external investigations were relied upon to resolve concerns regarding spark generation of the apparatus. Specifically, test conditions and spark generation results from impact between light metals and steel from the technical literature were analyzed and compared to the impact conditions which occur during operation of the H1571. Several factors were revealed which played consequential roles in influencing the tendency for sparking. The magnitude of the impact energy, the surface condition (oxidation and roughness), the impact angle, the hardness, and material composition are all significant factors that affect spark propensity. By comparing these factors with conditions that exist in this case, it was possible to qualitatively assess the probability for spark generation during routine operation of the H1571. Judging from the design, the materials used, the materials' surface conditions, and the operation of the H1571 system, a spark generation event was found to be virtually impossible. 13 refs., 3 figs.