被动柔性防护网中减压环力学试验及有限元分析  

Full scale test and FEM simulation to ring-type brake energy dissipater in falling rock protection

作　　者：刘成清[1,2] 陈林雅 陈驰[3] 邓永祥[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031 [3]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《岩石力学与工程学报》2016年第6期1245-1254,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51278428;51308471);中央高校基本科研业务费专项资金资助项目(2682014CX066)~~

摘　　要：为研究被动柔性防护网中减压环力学模型和耗能计算公式,首先,分析减压环的作用机制,得到其受力性能的主要影响因素为:预紧力、铝套筒长度、钢管壁厚和钢管环径;接着,进行减压环力学试验及有限元分析,验证结果与试验结果吻合较好;然后,进一步研究主要影响因素下减压环的荷载–位移曲线及其耗能特点,并结合工程实例,对比分析有减压环和无减压环时被动柔性防护网在落石冲击下的动力响应。研究结果表明:(1)减压环启动荷载随铝套筒长度的增大或钢管环径的减小而增加。其耗能在一定范围的铝套筒长度下变化较显著,而钢管环径对耗能的影响不大;(2)减压环启动荷载及耗能随着预紧力或钢管壁厚的增大而增加;(3)减压环的荷载–位移曲线满足三阶段变化规律,提出的三折线分析模型能够很好地反映减压环荷载–位移曲线特点,给出的耗能计算公式便于减压环的设计及工程应用;(4)减压环能使被动柔性防护网的柔性增强,冲击作用时间延长,并能降低与减压环连接的拉锚绳、支撑绳等构件的耗能。The energy dissipater of ring-type brake for failing rock protection was studied to investigate the load-displacement curves and the energy dissipation formula. Firstly, the working mechanism of the energy dissipater of ring-type brake was described. The main factors of influence, such as the pretension, the length of aluminum sleeves, the thickness of the steel pipe and the diameter of steel pipe were obtained. Secondly, the full-scale tests and finite element analysis for verification were carried out and the results were in good agreement with each other. Thirdly, the load-displacement curves and the energy dissipation characteristics under the action of the main influence factors were further studied based on the finite element simulation of the engineering examples. The starting force of the energy dissipater of ring-type brake was found to increase with the increasing of the length of the aluminum sleeves and the decreasing of the diameter of steel pipe. The energy dissipation changed significantly with the length of the aluminum sleeves in a certain range, while the diameter of steel pipe had a little effect on its energy dissipation. The staring force and energy dissipation of the energy dissipater of ring-type brake were increased gradually with the increasing of pretension or thickness of the steel pipe. The proposed tri-linear analysis model reflected well the characteristic of the load-displacement curves with three stages and the presented energy dissipation formula facilitated the design and engineering application of the energy dissipater of ring-type brake. The energy dissipater of ring-type brake enhanced the flexibility of the passive flexible protection and prolong the impacting time, also reduced significantly the energy consumption of the tension anchor rope and the supporting rope.

关 键 词：数值模拟 被动柔性防护网 减压环 力学试验 荷载–位移曲线 

分 类 号：O242[理学—计算数学]