摘要
钢管混凝土柱是性能优越的承重构件,在遭受意外坠物、爆炸冲击等轴向荷载后,一旦发生破坏,极易引起严重的经济损失和人员伤亡。本文采用数值模拟和理论分析相结合的方法,对钢管混凝土轴向冲击作用下的动态力学性能展开研究。基于LS-DYNA软件建立了精细化数值模型并开展模型验证,对轴向冲击荷载下钢管混凝土试件的内能分配情况展开分析,随后探究了钢管强度、混凝土强度、含钢率和长径比等因素对其动态力学性能的影响。结果表明:在轴向冲击荷载作用下,混凝土的塑性变形为钢管混凝土试件抗冲击的主要能量消耗部分,约占总能量的85%以上;相同冲击速度下,钢管混凝土试件的动态抗压强度与材料强度、含钢率呈正相关,与长径比呈负相关。基于已有模型提出了修正后的动态应力-应变关系,可较好地反映钢管混凝土在轴向冲击荷载下的动态力学行为。
Concrete-filled steel tube(CFST)columns are load-bearing components with superior perfor-mance.If the column is damaged by axial loads such as accidental falling objects and explosion impacts,this will cause serious economic losses and casualties.This study investigates the dynamic mechanical behavior of CFST columns under axial impact through integrated numerical simulations and theoretical analyses.A refined numerical model was established using LS-DYNA software and validated through experimental comparisons.The energy distribution characteristics within CFST specimens under axial impact were systematically ana-lyzed,followed by parametric investigations on the influences of steel tube strength,concrete strength,steel ratio,and slenderness ratio.Results demonstrate that the plastic deformation of concrete serves as the primary energy dissipation mechanism under axial impact,accounting for approximately 85%or more of the total en-ergy absorption.At identical impact velocities,the dynamic compressive strength of CFST specimens shows positive correlations with material strengths and steel ratio,but a negative correlation with slenderness ratio.A modified dynamic stress-strain relationship was proposed based on existing models,effectively characterizing the dynamic response of CFST columns under axial impact loading.
作者
臧倩
宗周红
李明鸿
林元铮
李佳奇
余道兴
ZANG Qian;ZONG Zhouhong;LI Minghong;LIN Yuanzheng;LI Jiaqi;YU Daoxing(Engineering Research Center of Safety and Protection of Explosion and Impact of Ministry of Education,Southeast University,Nanjing 211189,China;School of Civil Engineering,Southeast University,Nanjing 211189,China)
出处
《东南大学学报(自然科学版)》
北大核心
2025年第6期1592-1599,共8页
Journal of Southeast University:Natural Science Edition
基金
国家自然科学基金资助项目(52208469)
江苏省自然科学基金资助项目(BK20220850)。
关键词
钢管混凝土
轴向冲击荷载
数值模拟
动态本构模型
concrete-filled steel tube(CFST)
axial impact loading
numerical simulation
dynamic constitu-tive model
