被动柔性防护网结构的累计抗冲击性能研究
发布时间：2018-11-26 20:04
【摘要】：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。
[Abstract]:In view of the current situation that passive flexible protective net is subjected to accumulative impact in actual engineering, the full-scale rockfall test of protective net structure with nominal energy level of 1 500 kJ is carried out, and continuous accumulative impact is carried out in the condition of no repair. Based on the explicit algorithm of LS-DYNA, the whole process of the experiment is simulated, and the accumulative shock simulation of the system with nominal energy levels of 750,3000 and 5,000 kJ is carried out by numerical analysis. Combined with test and numerical simulation, the force transfer mechanism, deformation characteristics and energy dissipation distribution of the structure under accumulative impact are studied. The results show that the passive flexible protective net which has successfully intercepted 1 500 kJ rockfall impact still has the ability to withstand four consecutive impacts of left and right span 750 kJ and middle span 1 500 kJ. With the development of accumulative impact, the main energy consumption of the system changes from the second stage to the third stage, the proportion of energy consumption of the decompression ring decreases and the energy consumption ratio of the mesh increases. Combined with the performance curve of each working condition, the formula of calculating the energy reserve coefficient and the energy ratio of each stage is established, and the energy reserve of the system can be predicted by the formula. The results provide a theoretical basis for the design of passive flexible protective net structure.
【作者单位】： 西南交通大学土木工程学院;成都理工大学地质灾害防治与地质环境保护国家重点实验室;西南石油大学土木工程与建筑学院;
【基金】：国家自然科学基金资助项目(51408498) 成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金资助项目(SKLGP2016K013) 中央高校基本科研业务费专项资金资助项目(2682017CX006)~~
【分类号】：P642.2
本文编号：2359496
[Abstract]:In view of the current situation that passive flexible protective net is subjected to accumulative impact in actual engineering, the full-scale rockfall test of protective net structure with nominal energy level of 1 500 kJ is carried out, and continuous accumulative impact is carried out in the condition of no repair. Based on the explicit algorithm of LS-DYNA, the whole process of the experiment is simulated, and the accumulative shock simulation of the system with nominal energy levels of 750,3000 and 5,000 kJ is carried out by numerical analysis. Combined with test and numerical simulation, the force transfer mechanism, deformation characteristics and energy dissipation distribution of the structure under accumulative impact are studied. The results show that the passive flexible protective net which has successfully intercepted 1 500 kJ rockfall impact still has the ability to withstand four consecutive impacts of left and right span 750 kJ and middle span 1 500 kJ. With the development of accumulative impact, the main energy consumption of the system changes from the second stage to the third stage, the proportion of energy consumption of the decompression ring decreases and the energy consumption ratio of the mesh increases. Combined with the performance curve of each working condition, the formula of calculating the energy reserve coefficient and the energy ratio of each stage is established, and the energy reserve of the system can be predicted by the formula. The results provide a theoretical basis for the design of passive flexible protective net structure.
【作者单位】： 西南交通大学土木工程学院;成都理工大学地质灾害防治与地质环境保护国家重点实验室;西南石油大学土木工程与建筑学院;
【基金】：国家自然科学基金资助项目(51408498) 成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金资助项目(SKLGP2016K013) 中央高校基本科研业务费专项资金资助项目(2682017CX006)~~
【分类号】：P642.2
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1 陈林雅;被动柔性防护网在滑坡堆积作用下的压力概率统计及其受力响应研究[D];西南交通大学;2016年
，本文编号：2359496
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