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| Cumulative impact resistance of passive flexible protective structure |
| QI Xin1，2，YU Zhixiang1，XU Hu1，MENG Qingcheng3，ZHAO Lei1，ZHAO Shichun1 |
(1. School of Civil Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China；
2. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，
Chengdu，Sichuan 610059，China；3. School of Civil Engineering and Architecture，Southwest Petroleum University，
Chengdu，Sichuan 610500，China) |
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Abstract 针对被动柔性防护网在实际工程中承受累计冲击的现状，开展标称能级为1 500 kJ的防护网结构足尺落石试验，在无修复状态下进行连续累加冲击；基于LS-DYNA的显式算法，对试验进行全过程模拟；进而采用数值分析开展标称能级为750，3 000和5 000 kJ系统的累计冲击模拟。结合试验与数值仿真研究累计冲击作用下，结构的传力机制、变形特征、耗能分布。结果表明：中跨已成功拦截1 500 kJ落石冲击的被动柔性防护网，仍具有继续承受左跨750 kJ、右跨750 kJ和中跨1 500 kJ共4次连续冲击能力。系统的冲击力学行为具有明显的三阶段特征，随着累计冲击的开展，系统的主要耗能由第二阶段转换为第三阶段；减压环的耗能比例降低，网片的耗能比例提高；结合各工况的性能曲线，建立系统的能量储备系数与各阶段能量比例的相关计算公式，采用该公式可对系统的能量储备进行预估，研究结果为被动柔性防护网结构的设计提供理论基础。
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2017, Vol. 36 
