摘要
针对PBX材料的拉压不对称性,基于断裂相场变分理论,结合广义Maxwell黏弹性本构模型,采用应变张量谱分解的方法对弹性能进行分解,建立了黏弹性断裂相场模型。采用建立的模型开展了典型PBX材料的单轴拉压、围压压缩、带孔板压缩及细观结构压缩等仿真分析,得到的单轴拉压应力—应变曲线、围压压缩应力—应变曲线、带孔板压缩裂纹形貌、细观结构压缩裂纹形貌均与试验结果较为一致,且单轴拉压强度描述误差小于2.2%,压缩强度随围压变化的斜率误差小于3%,带孔板在相同裂纹长度时的载荷误差小于12%。结果表明,提出的黏弹性断裂相场模型能准确考虑PBX材料的拉压不对称性,并且可以自然地描述不同围压下的力学行为,同时可以无需特殊处理便进行PBX多裂纹萌生、扩展、分叉和融合行为的仿真分析。相场法在描述PBX材料的力学行为以及PBX结构的断裂行为上具有显著的优势和潜力。
Based on the fracture phase-field method and the generalized Maxwell viscoelastic constitutive model,a viscoelastic fracture phase field model was established,where the elastic energy was decomposed using strain tensor spectrum decomposition to considering the tension-compression asymmetry of PBX materials.The simulation analysis of typical PBX materials such as uniaxial tension-compression,confining compression,perforated plate compression and microstructure compression was carried out by using the established model.The stress—strain curves of uniaxial tension-compression and confining compression,compressive crack morphologies of perforated plate and meso-structure obtained by this model are in good agreement with the experimental results.To be specific,the description error of uniaxial tensile and compressive strength is less than 2.2%,the slope error of compressive strength under confining pressure is less than 3%,and the load error of perforated plate with the same crack length is less than 12%.The results show that the proposed viscoelastic fracture phase-field model can not only accurately consider the tension-compression asymmetry of PBX materials,but naturally describe the mechanical behavior under the different confining pressures.In addition,the simulation analysis of multiple crack initiation,propagation,bifurcation and fusion behavior of PBX can be carried out without special treatment.Phase-field method has obvious advantages and potential in describing the mechanical behavior of PBX materials and the fracture behavior of PBX structures.
作者
袁洪魏
唐维
YUAN Hong-wei;TANG Wei(Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang Sichuan 621900,China;Graduate School of China Academy of Engineering Physics,Beijing 100193,China)
出处
《火炸药学报》
EI
CAS
CSCD
北大核心
2023年第6期484-494,I0001,共12页
Chinese Journal of Explosives & Propellants
基金
国家自然科学基金(No.12002322,No.12002323)。
关键词
材料力学
高聚物黏结炸药
PBX
黏弹性
拉压不对称性
多裂纹分叉融合
断裂相场法
material mechanism
ploymer bonded explosive
PBX
viscoelasticity
tensile-compressive asymmetry
multi-crack bifurcation fusion
fracture phase field method
