基于塑性损伤理论的PBX圆拱结构变形破坏分析

为研究PBX构件在复杂应力状态下的力学行为，采用塑性损伤模型对PBX圆拱结构在压缩条件下的变形与破坏过程进行模拟，分析了不同约束状态下PBX构件的承载能力、变形破坏过程与裂纹形貌，发现试件的承载能力随着端部摩擦的增强而提高，经过与实验结果的对比可知，当摩擦因数取0.2时模拟得到的失效载荷为908.9 N，与实验结果的平均值921.3 N最为接近.在约束状态下圆拱的承载能力有了较大提高，并且在裂纹出现后试件仍然能够继续承载.通过数值模拟可知端部约束条件抑制了试件的变形和裂纹的扩展.在强约束条件下试件发生了二次破坏，通过数值模拟再现了这一过程，通过与实验的对比发现数值模拟在描述裂纹形貌、载荷等方面有较好的结果. 

Deformation and Fracture Analysis of PBX Arch Specimens Based on Plasticity Damage Theory

Plasticity damage theory was used to simulate the deformation and fracture process of PBX circular arch specimens subjected to compression. The bearing capacity and crack shape of specimens at constraint conditions were analyzed. The comparison between experiment and simulation shows that the bearing capacity of specimens rises with the increase of friction. Simulation results agree with the experiment data well when the friction coefficient equals to 0.2; the bearing capacity of specimens is greatly improved at restriction conditions, and the specimens can still bear loading when a crack appears; the specimens break twice at strong restriction when it comes to continued loading, and this process has been reproduced by simulation. The simulation have a good agreement with experimental results in terms of the shape of cracks and carrying capacity. So plasticity damage model can be used to analyze the deformation and fracture of PBX specimens.