Research On The Key Technology Of Non-primary DDT Detonator

Cylindrical metal inner tubers filled up with crystal PETN (pentaerythritol tetranitrate) as detonation device to replace the primary explosive part to design the non-primary detonator and make experimental study based on the principle of high explosive deflagration to detonation transition(DDT). A numerical simulation research had been made on the DDT formation of PETN of the cylindrical metal inner. The main results were as following:(1) The results show that the PETN within the metal inner tuber can trigger deflagration and later transition to detonation at a proper charge density.With stronger constraint strength and longer length of metal inner tuber, the range of chager density for DDT of crystal PETN in the inner tuber is wilder and the formation of DDT is easier.(2) The crystal PETN of the shorter inner tuber can trigger deflagration and later transition to detonation ignited by HGL high-energy ignition composition, which means the detonation-induced distance of DDT of crystal PETN in the steel inner tube can reduce by increasing ignition strength. The common electrical fuse head-can ignite crystal PETN of the steel inner tuber directly and make it form for DDT. Use SCB as igniton conditions, the detonator can detonation by using RDX and PETN as ignition composition.This detonator use all high explosive and SCB of anti-static electricity, anti-stray current, short of action time, which can make the production and use of detonator more safty.(3) The charge conditions of second charge had a significant influence on axial output energy of non-primary detonator.lt can increase the axial output energy by using high sensitivity high explosive and increase the charger density of the second charge at some range of charger density.(4) A numerical simulation research had been made on the DDT formation of PETN of the cylindrical metal inner by LS-DYNA software.The simulation result show that the PETN go though the deflagration to detonation transition phase, and formation of a stable detonation act on the second charge and first charge, and detonated the second charge and first charge progressively.