爆炸荷载下预制节段拼装双层钢管混凝土墩柱的动力响应数值模拟  

Numerical simulation on dynamic response of precast segmental CFDST columns under blast loading

作　　者：李明鸿[1,2] 刘晏辰 夏梦涛 宗周红[1,2] 甘露 陈振健 Li Minghong;Liu Yanchen;Xia Mengtao;Zong Zhouhong;Gan Lu;Chen Zhenjian(School of Civil Engineering,Southeast University,Nanjing 211189,China;Engineering Research Center of Safety and Protection of Explosion&Impact of Ministry of Education,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学土木工程学院,南京211189 [2]东南大学爆炸安全防护教育部工程研究中心,南京211189

出　　处：《东南大学学报（自然科学版）》2024年第3期647-657,共11页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(52208469);中国博士后科学基金资助项目(2020M681459,2022T150120);江苏省自然科学基金资助项目(BK20220850);中央高校基本科研业务费专项资金资助项目。

摘　　要：为提升装配式公路桥梁的抗爆防护能力,提出了一种新型预制节段拼装双层钢管混凝土(PS-CFDST)组合墩柱.基于非线性显式动力分析程序LS-DYNA建立了新型PS-CFDST墩柱在爆炸荷载作用下动力响应分析的精细有限元模型,并通过已有试验结果验证了模型的准确性.对爆炸荷载作用下PS-CFDST墩柱的动力响应进行数值模拟分析,研究了PS-CFDST墩柱在爆炸荷载作用下的破坏过程、损伤机理和耗能机制.运用参数化分析方法,研究了爆炸距离、节段数量和预应力水平等关键参数对PS-CFDST墩柱动力响应的影响,并在此基础上提出了PS-CFDST墩柱的抗爆设计建议.结果表明:PS-CFDST墩柱除通过材料塑性损伤耗能之外,节段接缝界面滑移耗能机制对耗能贡献可达40%以上;增大墩柱可接近距离是提升墩柱抗爆安全性的有效手段,增大预应力有利于减小柱中最大水平位移和墩底剪切滑移,从而提升PS-CFDST墩柱的抗爆性能.To improve the blast resistant performance of prefabricated highway bridges,a new type of precast segmental column,namely precast segmental concrete-filled double-skin steel tube(PS-CFDST)column,was proposed.A high-fidelity physical-based model was established using the nonlinear dynamic analysis program LS-DYNA to analyze the dynamic response of the PS-CFDST column under blast loading.The numerical model was comprehensively validated with existing experimental results in literature.Numerical simulations were then conducted to study the damage evolution,failure mechanism and energy absorption of PS-CFDST columns under blast loading.The effects of critical design parameters,including explosion distance,number of segments and prestress force level,on the dynamic response of PS-CFDST columns were studied by means of parametric analysis,and on this basis,some anti-explosion design recommendations for PS-CFDST columns were proposed.The results indicate that the energy dissipated by joint slippage can contribute to more than 40%of the column energy dissipation except for the energy dissipated through the material plastic damage.Increasing the accessible distance is the most effective measure to improve the column safety under blast loading.The increase of prestress force is beneficial to decrease the column maximum lateral displacement and the shear slippage at the column bottom and therefore improve the blast resistance of PS-CFDST columns.

关 键 词：预制节段拼装墩柱 双层钢管混凝土 数值模拟 爆炸荷载 动力响应 损伤机理 

分 类 号：U448[建筑科学—桥梁与隧道工程]