摘要
正交钢丝环链网片广泛应用于落石防护工程,具有复杂的非线性力学行为,针对目前常用的离散接触态环梁单元模型计算效率低的问题,提出了一种薄膜等效模拟方法。开展了网片加载试验,研究了试件的P-Δ特性,分析并揭示了网片的正交化受力特征及正交拉力带的形成机制。基于最短传力路径原理构建了薄膜面外加载的正交拉力带解析模型,推导了等效薄膜的应力-应变关系,建立了薄膜顶压有限元模型。研究表明:采用指数强化弹塑性本构的薄膜能够在数值模拟中准确反演网片面外加载的宏观力学行为,模拟得到的顶破力、顶破位移和耗能能力与试验相比误差均小于10%。同时,采用该文方法建立的冲击力学模型求解得到的冲击响应与既有文献的试验结果吻合较好,加速度峰值误差4.3%。最后基于冲击模型,对比了等效模型与环梁模型的计算效率,等效方法的计算效率可提高10倍以上。
The orthogonal steel ring net widely used in rockfall protection engineering has complex nonlinear mechanical behavior.A membrane equivalent simulation method is proposed because of the low computational efficiency of a circular beam model.The loading test of a ring net was carried out,the P-Δcharacteristics of the specimens were studied,the orthogonal mechanical characteristics of the ring net was analyzed,and the formation mechanism of the orthogonal tension band was revealed.Based on the principle of the shortest force transfer path,the membrane analytical model of the orthogonal tension band loaded out of plane loading was constructed,the stress-strain relationship of membrane was derived,thereby the membrane FEM model loaded out of plane loading was established.The results showed that membrane with exponential strengthening elastoplastic constitutive model can accurately recur the mechanical behavior of a steel ring net.Compared with the test results,the relative errors of the membrane ultimate force,of the displacement,and of the energy dissipation capacity were less than 10%.In addition,the impact responses obtained by impact FEM model established by the equivalent method was in a good agreement with the test results of existing literatures,and the peak acceleration relative error was 4.3%.Finally,based on the impact FEM model,the calculation efficiency of the equivalent model was compared with that of the circular beam model.The calculation efficiency of the equivalent method can be increased by more than 10 times.
作者
金云涛
余志祥
骆丽茹
郭立平
张丽君
廖林绪
JIN Yun-tao;YU Zhi-xiang;LUO Li-ru;GUO Li-ping;ZHANG Li-jun;LIAO Lin-xu(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;National Engineering Laboratory for Prevention and Control of Geological Disasters in Land Transportation,Chengdu 611756,China;Research Center of Protection Structures Against Natural Hazards,Southwest Jiaotong University,Chengdu 610031,China)
出处
《工程力学》
EI
CSCD
北大核心
2021年第11期114-121,共8页
Engineering Mechanics
基金
国家重点研发计划课题项目(2018YFC1505405)
国家自然科学基金项目(51408498,51678504)
四川省科技计划重点项目(2018JY0029)
四川省重点研发项目(2019YFG0001)
四川省交通运输科技项目(2018-B-03)
四川省交通运输科技项目(2020-B-01)
交通运输行业重点科技项目(2020-MS3-101)。
关键词
防护工程
落石防护
正交钢丝环链网片
数值模型
薄膜
等效方法
计算效率
protection engineering
rockfall protection
wire-ring net
numerical model
membrane
equivalent method
computational efficiency
