拉伸载荷下PBX-9501裂纹产生的数值模拟  

Numerical Simulation of PBX-9501 Crack Generation Under Tensile Loading

作　　者：何各燚 刘占芳[1,2] 段连龙 HE Ge-yi;LIU Zhan-fang;DUAN Lian-long(College of Aerospace Engineering,Chongqing University,Chongqing University,Chongqing 400044,China;Chongqing Key Laboratory of Heterogeneous Material Mechanics,Chongqing 400044,China)

机构地区：[1]重庆大学航空航天学院,重庆400044 [2]非均质材料力学重庆市重点实验室,重庆400044

出　　处：《含能材料》2022年第7期736-743,共8页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金(U1830115)。

摘　　要：高聚物黏结炸药(Polymer Bonded Explosive,PBX)是由占极大体积分数的单质炸药颗粒与少量高聚物黏结剂组成的多相复合材料,其中颗粒与黏结剂的界面脱粘以及细观结构是影响材料力学性能的重要因素。可以通过将随机模拟方法与Voronoi方法相结合,建立细观尺度下PBX材料的代表性体积元进行分析。但当颗粒为多级配时,该方案生成的模型大颗粒周围的颗粒呈条状散射形状,因此本研究在Voronoi方法的基础上改进了PBX细观结构的建模方法。首先根据PBX-9501颗粒与黏结剂的细观界面特性,采用三阶段黏结界面本构关系,对PBX-9501材料在静态拉伸下颗粒与黏结剂界面的损伤演化进行数值模拟,获得的PBX-9501宏观力学性能与实验数据比较吻合,其次对使用有限元隐式静力分析时的收敛性与代表体积元尺寸之间的关系进行讨论,结果表明代表体积元尺寸越大则模拟界面脱粘的收敛性越差。Polymer Bonded Explosive(PBX)is a multiphase composite material composed of pure explosive particles occupying a high volume fraction and a little polymer binder. The interface debonding between particles and binder and the mesostructure play a critical role in the mechanical properties of the material. In this paper,according to the stochastic simulation method com-bined with the Voronoi method,the representative volume element model of PBXs is established at the mesoscale. When the particles generated by Voronoi method are multi-graded,the particles around the large ones show a strip-scattering shape. The method of mesostructure modeling of PBXs was improved based on Voronoi method. Considering the mesoscopic interface characteristics of PBX-9501,the interface damage evolution between particle and binder under static tension was numerically simulated by using the constitutive relationship of three-stage bonding interface. The results show that the macroscopic mechanical properties of PBX-9501 agree well with the experimental data. The relationship between convergence and the size of representative volume element is discussed. It is concluded that the larger the size of the representative volume element is,the worse the convergence of the interface debonding simulation is.

关 键 词：高聚物黏结炸药 随机模型 DELAUNAY三角形 界面脱粘 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O34[理学—固体力学]