爆炸冲击波与破片联合作用下UHP-FRC墙体破坏机理与加固研究

Under the attacks of the earth penetration weapons and man-made explosive devices, the wall of the ground buildings always endures the combined effects of blast wave and high-speed fragments. Ultra-high performance fiber-reinforced concrete (UHP-FRC) with distinguished high compressive strength and roughness is the most potential construction materials for anti-penetration/blast structures. In this project, firstly, the optimal mixing proportion of UHP-FRC under intense dynamic loadings will be proposed based on a series of static, dynamic tests as well as the 3D meso-scale numerical simulations. Secondly, by improving the yield surface, tensile damage, Lode angle and etc., the modified HJC constitutive model as well as the confirmation approach for the related parameters of UHP-FRC will be obtained. Thirdly, the high-speed impact and the anti-blast field tests on prototype bare UHP-FRC and FRP reinforced UHP-FRC walls, as well as the numerical simulations will be carried out. The failure mechanisms of bare UHP-FRC as well as its composite structure under the sole and combined actions of blast wave and high-speed fragments will be revealed. Furthermore, the related design and calculation approach, the fortification measures as well as the technical code will be established. The prospective achievements have significant research and military meanings in improving the theoretical system of UHP-FRC under intensive dynamic loadings, guiding the preparation and engineering applications of UHP-FRC, formulating the anti-blast standard, so as to guarantee the national defense and the urban securities.

钻地武器和人造爆炸装置作用下地上建筑墙体通常承受爆炸冲击波和高速破片的联合作用。超高性能纤维增强混凝土（UHP-FRC）所具有的优异强度和韧性使其成为最具前景的抗爆结构材料。本项目拟基于静、动载实验和三维细观数值模拟研究，确定抗强动载作用下UHP-FRC最优配合比设计方法；提出对屈服面、拉损伤、Lode角等进行改进的HJC本构模型及UHP-FRC材料参数快速确定算法；开展UHP-FRC及后覆纤维织物UHP-FRC墙体的高速冲击实验以及野外原型墙体抗TNT爆炸实验和数值研究，揭示UHP-FRC墙体及其复合结构抗爆炸冲击波和破片单独和联合作用机理，进一步提出相关计算设计方法和加固措施并形成《指南》。预期研究成果对于完善UHP-FRC材料抗强动载作用理论体系，指导抗强动载作用UHP-FRC制备及其工程应用，制定军、民用重要地面建筑结构抗爆设防标准，保障国防和城市安全具有重要的研究价值和军事意义。

本课题基于实验研究、理论分析和数值模拟方法，研究了UHPC的静、动态力学性能以及抗破片弹丸的计算模型。针对UHPC的静态力学性能，开展了立方体/轴心压缩、直接拉伸、四点和三点弯曲实验，分析了钢纤维类型（微细平直型和端钩型）和体积掺量（0%、0.5%、1.0%、1.5%、2.0%和2.5%）对其静态力学性能的影响；利用50mm直径变截面分离式霍普金森压杆试验装置，分别开展了UHPCC的冲击压缩实验和层裂实验。分析了不同钢纤维掺量（0%、1.0%和2.0%）和类型（微细平直型和端钩型）以及应变率（14.3s-1~328.4s-1）对其动态力学性能的影响，提出了适用于不同钢纤维掺量和类型UHPC的动态压缩和拉伸DIF公式；开展了7.62mm子弹打击裸UHP-BASFRC墙体、被覆UHMWPE或CFRP纤维布复合UHP-BASFRC靶体的实验研究，并提出了相应的墙体抗力计算方法。进一步开展了平头弹体侵彻UHP-BASFRC靶体的补充实验研究。针对实验中出现的刚性侵彻、侵蚀侵彻两种侵彻机制分别开展了讨论研究，提出了准确度较高的计算方法。