考虑T应力的PBX裂纹尖端失效区和起裂行为  

PBX Crack Tip Failure Zone and Fracture Behavior Considering the T-stress

作　　者：董天宝[1] 袁洪魏 赵龙 唐维[1] DONG Tian-bao;YUAN Hong-wei;ZHAO Long;TANG Wei(Institute of Chemical Materials,CAEP,Mianyang 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：《含能材料》2020年第5期456-463,共8页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金资助(11604309)。

摘　　要：为了研究高聚物粘结炸药(PBX)结构在复杂应力状态下裂纹的起裂特征,针对中心贯穿斜裂纹的无限大平板模型,基于考虑T应力的裂纹尖端应力场和Drucker-Prager强度准则,理论上给出了考虑材料拉压比、泊松比、静水压力、应力状态、裂纹面闭合摩擦以及T应力的PBXⅠ-Ⅱ复合型裂纹尖端失效区隐式控制方程。利用裂纹尖端失效区最小半径起裂准则,研究了T应力对PBX裂纹尖端失效区和起裂行为的影响。理论研究表明,远场拉伸下,T应力导致裂尖失效区增大(0°<β<45°)或减小(45°<β<90°),T应力使裂纹起裂角减小;远场压缩下,裂纹处于纯Ⅱ型状态,裂纹面闭合摩擦效应减小了裂尖失效区,但不影响起裂角。T应力使压剪裂纹起裂角增大并减小了失效区。同时,T应力使最危险裂纹倾角β0明显增大。因此,研究PBX裂纹起裂行为,需要充分考虑裂纹尖端T应力的影响。In order to study the crack initiation characteristics of polymer bonded explosive(PBX)structures under complex stress conditions,the implicit governing equation of PBXⅠ-Ⅱmixed mode crack failure zone was obtained.The equation considered tension-compression ratio,Poission′s ratio,hydrostatic pressure,stress state,crack surface closure friction and T-stress theoretically.The whole model was based on a infinite plate model with a centeral slanting crack and the crack tip stress field considering T-stress and Drucker-Prager strength criterion.By applying the minimum radius fracture criterion of crarck tip failure zone,the effects of T-stress on crack tip failure zone and fracture of PBX was studied.Theoretical study indicates that,for far field tension state,T-stress leads to an increase(0°<β<45°)or decrease(45°<β<90°)in the crack tip failure zone and decrease of the fracture angle;for far field compression state,the crack is only in the II mode state.Due to crack closure,friction effect leads to a significant reduction of the crack tip failure zone,but does not influence the fracture angle.T-stress leads to the increase of the fracture angle and the decrease of the crack tip failure zone for compression-shear crack.Meanwhile,T-stress leads to the obvious increase of the most dangerous crack angle β0.Therefore,it is necessary to consider the effects of T-stress on studying the crack initiation behavior of PBX.

关 键 词：高聚物粘结炸药(PBX) T应力 复合型裂纹 裂纹尖端失效区 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O346.1[理学—固体力学]