高燃速推进剂成型过程中的安全性分析

为研究高燃速推进剂成型过程中的安全性,根据配方组成和工艺条件,对其压伸过程的热点形成因素进行了理论分析,并采用热-结构耦合方法,选择有限元软件ABAQUS对其不同工艺条件下的压伸过程进行了建模分析。结果表明:在压伸过程中,物料在收缩段承受的压力最大,且温度变化显著。物料中残留的气泡是影响高燃速推进剂压伸成型过程安全性的主要因素。当物料中有残留气泡时,随压伸过程所加的载荷不同,气泡的最高温度会显著上升,载荷为15MPa时,气泡的最高温度可达139.3℃;载荷为20 MPa时,温度可达264.2℃。

Safety analysis of the high combustion rate propellant in the formulating process

The present paper is inclined to make an analysis of the constituent factors of the hot spots in the propellant based on the constituent components and the resulting conditions in the extrusion process so as to identify and determine the safety-affecting factors of such propellants in the said process via the finite element software known as ABAQUS with the thermo-structure coupling method. Actually,the modeling analysis can be done in the extrusion process in different conditions. The results of our analysis prove that the autocatalytic thermal decomposition of high burning rate propellant turns to be one of the most likely causes that account for the dangerous risk events. And,more narrowly speaking,the initial thermal decomposition temperature has to be taken as the critical process one,in which the materials are to be contracted and squeezed into the necessary segments at a significantly increasing temperature. For example,to the homogeneous materials,it is possible to raise the temperature up to only 4. 7 ℃ with the loading 30 MPa,which remains far from the critical processing temperature for high combustion propellants. The reason for it is that the pressure filtration process can only be realized in a non-vacuum state,in which the gases of the materials can be removed totally. What is more,the residual bubbles in the materials serve as the main factors that influence the safety of the high burning rate of the propellant in the extrusion process. It is only when there are enough residual bubbles in the materials that the material system can be made to reach the highest temperature needed for the materials of different loadings to be promoted enough significantly. For example,the bubble has to be heated to the temperature of 139. 3 ℃ in case when the load were to be 15 MPa. On the other hand,if the load is 20 MPa,it is necessary for the temperature to be pushed up by 264. 2 ℃. Moreover,if the load is 25 MPa,the maximum temperature of the material system should be made to reach a temperature of 282. 7 ℃,for it is only at such a temperature that can satisfy and guarantee the combustion or the thermal explosion of the material system. Therefore, in order to ensure the safety of the extrusion process,it is necessary to confine the loading limit less than 15 MPa.