Witness plates Additional

Two principles can be applied in the experimental determination of the initiating strength of boosters. One relates to the determination of the damage effect caused in the witness plate by the detonation of the booster, viiereas the other concerns the determination of the capability of a booster to detonate a test explosive charge, which in addition to the explosive, also contains an inert component. The possible variant of the latter principle implies the determination of the so-called failure of detonation distance, i.e., the distance at which the detonation process is broken down. The failure of detonation distance can be determined on the basis of the traces that are left on a copper or brass plate after the detonation took place. The setup for the determination of the failure of the detonation distance is shown in Figure 2.44. 

After fabrication, ail the panels were interrogated by pulse echo ultrasound (10 MHz) and film X-ray. There was no indication of any delamination and no gross porosity regions were noted in the panels. In addition, each panel had two tensile bars extract for witness testing at room temperature. All samples tested failed above a 0.3% strain to failure requirement. Hence, all panels were accepted into the testing effort. Samples were cut out of the accepted plates and holes where drilled in diameters of 2.286 and 4.572 mm at the center of the lecimens forming 20% of the width of the specimen. 

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