基于内聚力法则的高能硝酸酯增塑聚醚推进剂开裂过程细观模型  

Mesoscopic Model of Cracking Process of NEPE Propellant Based on Cohesive Zone Model

作　　者：侯宇菲 许进升[1] 古勇军 周长省[1] HOU Yufei;XU Jinsheng;GU Yongjun;ZHOU Changsheng(School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China;Shanxi North Xing' an Chemistry Industry Co. , Ltd. , Taiyuan 030008, Shanxi, China)

机构地区：[1]南京理工大学机械工程学院,江苏南京210094 [2]山西北方兴安化学工业有限公司,山西太原030008

出　　处：《兵工学报》2020年第11期2206-2215,共10页Acta Armamentarii

摘　　要：为从细观角度研究高能硝酸酯增塑聚醚(NEPE)推进剂的破坏机理,采用分子动力学算法生成细观颗粒填充模型,利用Python脚本语言在颗粒与基体界面及基体内部嵌入零厚度粘结单元。针对NEPE推进剂延展性失效特点,基于多项式内聚力法则建立一种多项式-梯形内聚力法则,并进行子程序VUMAT开发。对比考虑颗粒与基体界面脱湿及基体失效的数值模拟结果发现,NEPE推进剂颗粒与基体界面脱湿引起基体内部形成孔洞,孔洞周围形成的高应力区是导致推进剂开裂的关键。实验验证得知,多项式-梯形内聚力法则较双线性内聚力法则和多项式内聚力法则能更准确地描述推进剂的失效过程。For the sake of acquiring the mesoscopic damage mechanism of nitrate ester plasticized polyether(NEPE)propellants,a random particle model based on the molecular dynamics theory is established.The zero-thickness cohesive elements are embedded in the matrix and interface in random particle model by using Python scripting language.Considering the ductile failure of NEPE propellant,a novel polynomial-trapezoidal cohesive zone model is presented based on polynomial cohesive zone model,and a vectorized user defined material subroutine VUMAT is developed.By comparing the numerical results of particle/matrix interface dewetting model and matrix damage model,it can be concluded that the particle/matrix interface dewetting of NEPE propellants causes formation of the holes in the matrix,and the high stress around the holes is the major factor that leads to the cracking of propellants.Experimental results validate that the polynomial-trapezoidal cohesive zone model can describe the cracking process of NEPE propellants more accurately compared to bilinear cohesive zone model and polynomial cohesive zone model.

关 键 词：高能硝酸酯增塑聚醚推进剂 零厚度粘结单元 多项式-梯形内聚力法则 颗粒与基体界面脱湿 基体失效 数值模拟 

分 类 号：V512.3[航空宇航科学与技术—航空宇航推进理论与工程]