基于XFEM的PBX炸药巴西实验断裂行为研究

Study on Fracture Behavior of the Brazilian Test of PBX Explosives Based on XFEM

  • 摘要: 为研究巴西实验测量PBX炸药间接拉伸力学行为中加载方式的影响,采用扩展有限元方法对标准巴西实验、圆弧巴西实验和橡胶垫巴西实验中PBX炸药的裂纹起裂、扩展和断裂行为进行了数值模拟,计算得到了位移和应力分布,分析了不同加载形式对圆盘试样的力学响应及变形破坏的影响.结果表明,计算得到的破坏过程,位移分布和应力分布与实验值及理论值相吻合,圆弧和橡胶垫巴西实验均可起到减小加载部位接触应力的作用,有助于防止次裂纹的产生,橡胶垫巴西实验最适合PBX炸药间接拉伸强度的测量.

     

    Abstract: In order to investigate the effects of different loading methods in the Brazilian test on indirect tensile mechanical behavior of PBX explosives,the deformation,damage and failure process in the Brazilian test,the arc Brazilian and the rubber-cushion Brazilian tests were simulated by using extended finite element method(XFEM).The distribution of displacement and stress were obtained.The effects of different loading methods on mechanical response,deformation and fracture were analyzed.The results show that the fracture path and the distribution of displacement and stress agree well with the experimental and analytical values.Compared with the Brazilian test,the arc Brazilian test and the rubber-cushion Brazilian test can reduce contact stress and help to prevent the generation of secondary cracks.It indicates that the rubber-cushion Brazilian test is better for measuring the tensile strength of PBX.

     

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