摘要
为研究城市桥墩抗撞性能,采用LS-DYNA有限元软件建立精细化车辆-桥墩碰撞模型,分析桥墩动力响应与撞击荷载。该模型考虑了应变率效应对钢筋与混凝土非线性材料力学性能的影响。基于40个车-桥碰撞工况,研究了撞击速度、撞击质量对撞击荷载和桥墩变形的影响,分析了撞击能量和桥墩破坏模式之间的关系。根据40个撞击荷载样本,提出撞击荷载经验公式与半正弦荷载时程曲线,用来计算撞击荷载峰值与反应时撞击荷载时程。将撞击荷载峰值分别与3种等效静力荷载和《公路桥涵设计通用规范》荷载限值进行对比。结果表明:规范中撞击荷载限值偏于不保守;采用等效静力荷载作为撞击荷载对城市桥墩进行抗撞评估偏于不安全。
In order to improve the crash worthiness of piers,a vehicle-pier collision numerical model was modeled by LS-DYNA and validated.Nonlinear material constitutive laws considering the strain-rate effect were used.Based on 40 collision cases,the effect of impact velocity and impact mass on impact force and impact behavior of piers was analyzed,and the relationship between impact energy and failure modes of the impacted piers was studied.According to 40 impact force samples,the peak impact force and half-sinusoidal load curve were developed.Using equivalent static method,the different equivalent static forces were obtained,and the results were compared with the current code.The results showed that the current impact design provision(JTG D60—2004) could be not conservative and the pier could be vulnerable to heavy vehicle collision.
作者
李瑞文
周德源
LI Ruiwen;ZHOU Deyuan(Department of Disaster Mitigation for Structures,Tongji University,Shanghai 200092, China)
出处
《结构工程师》
北大核心
2019年第2期83-92,共10页
Structural Engineers
基金
国家自然科学基金(51438010)
关键词
车桥碰撞
撞击荷载
等效静力荷载
有限元分析
vehicle-pier collision
impact force
equivalent static force
numerical analysis
