铝基复合泡沫填充管结构爆炸冲击破坏机理及吸能性能研究

Explosion and impact resistance of structures is research hotspot of civil engineering in recent years. Combining the latest achievements in materials science, the project presents a tube structure filled with Aluminum matrix syntactic foams for engineering structures anti - explosion protection. First of all, the influences of yield strength of the filling material, diameter-thickness ratio and slenderness ratio of the steel tube on static ultimate bearing capacity of the filled tube structure are analyzed systematically and design method for the filled tube structure under static load is put forward; Secondly, failure mode, damage mechanism and energy absorption effect of the filled tube structure under axial, lateral and oblique impact are studied by experiment and numerical simulation, energy transfer and conversion rules of the components during the impact process are analyzed, the calculation formula of structure bearing capacity is put forward; after that, dynamic response, failure mode, damage mechanism and energy absorption effect of the filled tube structure under explosive shock wave is studied by experiment to reveal the interaction between shock wave and the structure, unified failure criterion of the filled tube structure under explosion and the relationship between explosive shock wave and energy absorption protective capability of the structure are put forward; At the end, the structure which performs best on mechanical property and energy absorption is put forward, the protection design method of explosion and impact resistance based on the tube structure filled with Aluminum matrix syntactic foams is established. Achievements of this project will provide a new type of structure for explosion resistance protection of major engineering.

结构抗爆抗冲击问题是近年来土木工程领域的研究热点，本项目结合材料科学最新成果，提出一种铝基复合泡沫材料填充管结构用于工程结构抗爆防护。首先，系统分析填充材料屈服强度、钢管径厚比及长细比等因素对填充管结构静态极限承载力的影响规律，提出基于静载作用的填充管结构设计方法；其次，试验和数值模拟研究轴向、侧向以及斜向冲击下填充管结构的破坏模式、毁伤机理及吸能效应，分析构件在冲击过程中的能量传递、转化规律，给出结构的承载力计算公式；然后，试验研究填充管结构在爆炸冲击波作用下的动态响应、失效模式、毁伤机理及吸能特性，揭示冲击波与结构相互作用规律，提出填充管结构在爆炸作用下的统一失效破坏准则，给出爆炸冲击波与结构吸能防护能力之间的关系；最后，提出受力和吸能效果最优的结构形式，建立基于铝基复合泡沫填充管结构的抗爆抗冲击防护设计理论。本项目所取得的成果将为重大工程的抗爆防护提供一种新型结构形式。

本项目聚焦于工程领域中备受关注的结构抗爆抗冲击安全防护问题，以粉煤灰空心微球/铝基复合泡沫材料为填充体，外套金属薄壁空心管，制备出铝基复合泡沫填充管结构。共完成了68个试件在轴心压缩、横向压缩、三点弯曲及剪切等静力荷载作用下的力学性能试验，以及38个试件在轴心、横向以及跨中点冲击载荷作用下的动力试验。系统地考察了在多种荷载作用下铝基复合泡沫填充管结构的变形与破坏现象、失效机理与吸能特性。研究结果表明，相比普通泡沫铝，铝基复合泡沫填充管在静力荷载作用下的峰值荷载与比吸能可以提升15~20倍。相比于静力加载，填充管结构在动载条件下的变形不够充分、均匀，但由于惯性效应以及材料应变率效应的影响使得试件的峰值荷载明显提升，轴心受力试件的比吸能增长幅度可达20%左右。基于非线性动力有限元软件LS-DYNA，定量分析了静、动态荷载作用方式、填充管几何设计参数、填充材料强度等关键因素对填充管结构力学性能及吸能性能的影响。研究表明，填充管管壁厚度对横向压缩受力情况下的力学性能影响较小，而对轴心压缩受力情况下的影响较大，在一定范围内，管壁厚度的增加可以显著提高填充管结构的抗压承载能力。通过金相显微镜等试验仪器对材料内部微细观破坏机理进行观察分析，定性揭示了复合材料在宏观与微细观尺度下的破坏机制。通过抗爆抗冲击防护结构构件的优化对比分析，构建了铝基复合泡沫填充管结构的抗爆抗冲击防御设计理论，为重要工程结构抗爆抗冲击技术的应用实践提供充分的理论支持，也为新型复合材料的工程应用合理的拓展了空间。