基于Voronoi建模和Cohesive单元的PBX细观力学模型  

Meso-mechanical Model of PBX Based on Voronoi Modeling and Cohesive Elements

作　　者：李云欣 朱晓燕[1] 袁洪魏 文乾乾 唐维[1] LI Yun-xin;ZHU Xiao-yan;YUAN Hong-wei;WEN Qian-qian;TANG Wei(Institute of Chemical Materials,CAEP,Mianyang Sichuan 621999,China)

机构地区：[1]中国工程物理研究院化工材料研究所,四川绵阳621999

出　　处：《火炸药学报》2024年第7期632-639,I0003,共9页Chinese Journal of Explosives & Propellants

基　　金：国家自然科学基金(No.12002323)。

摘　　要：针对PBX的细观力学模型存在模型结构与真实PBX细观形貌不符、破坏行为描述不全面(仅考虑界面脱粘)、研究对象单一(大多针对PBX-9501)等问题,建立了基于Voronoi建模和Cohesive单元的PBX细观力学模型。首先,基于光学显微镜下的细观结构图,采用Voronoi方法构建了更贴近实际形貌的PBX炸药细观模型;然后,采用内聚力有限元方法在炸药晶体内部、黏结剂内部及炸药颗粒/黏结剂界面处都引入了Cohesive单元,以在二维尺度上实现任意路径破坏行为的模拟;最后,针对某HMX基-F2311黏结剂炸药和某HMX基-F2313黏结剂炸药标定了模型参数,模拟了这两种炸药的准静态拉伸行为。结果表明,两种炸药数值模拟的拉伸变形曲线、破坏应力、破坏应变都与试验数据吻合良好,表明该模型不仅适用于不同PBX炸药材料(线弹性PBX、非线性PBX)的变形行为描述,还可以分析PBX炸药在拉伸破坏过程中的细观机理,刻画不同PBX炸药的裂纹萌生、扩展和贯穿的过程。Aiming at the problems of the meso-mechanical model of PBX,such as the inconsistency between the model structure and the real meso-morphology of PBX,the incomplete description of failure behavior(only considering interface debonding),and single research object(mostly aiming at PBX-9501),a meso-mechanical model of PBX based on Voronoi modeling and Cohesive elements is established.Firstly,based on the meso-structure diagram under the optical microscope,the meso-structure model of PBX explosive is constructed by Voronoi method,which is closer to the actual morphology.Then,Cohesive finite element method is introduced into the interior of the explosive crystal,the interior of the binder and the interface of the explosive particle/binder by using the cohesive finite element method to simulate the failure behavior of any path on a two-dimensional scale.Finally,the model parameters are calibrated for a HMX/F2311 and a HMX/F2313 binder explosives,and the quasi-static tensile behavior of the two explosives is simulated.The results show that the numerical simulation of the tensile deformation curve,failure stress,and failure strain were in good agreement with the experimental data,which indicates that the model is not only suitable for describing the deformation behavior of different PBXs(linear elastic PBX and nonlinear PBX),but also can analyze the microscopic mechanism of PBXs in the tensile failure process.Furthermore,the model can describe the crack initiation,propagation and penetration of different PBX explosives.

关 键 词：物理化学 高聚物黏结炸药 PBX 细观力学 拉伸强度 Voronoi建模 代表体积单元(RVE) Cohesive单元 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O341[理学—固体力学]