冲击荷载作用下钢筋混凝土梁性能试验研究  

Experimental study on the behaviors of reinforced concrete beams under impact loadings

作　　者：许斌[1,2] 曾翔[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082

出　　处：《土木工程学报》2014年第2期41-51,61,共12页China Civil Engineering Journal

基　　金：国家自然科学基金重大研究计划重点项目(90715033)以及培育项目(91015007)

摘　　要：在前期无腹筋梁抗冲击试验研究的基础上,为了进一步深入探讨冲击荷载作用下钢筋混凝土梁的抗冲击性能,利用落锤试验机对一组简支配箍钢筋混凝土梁进行试验研究,分析了不同冲击锤重、冲击速度和冲击能量及二次冲击下钢筋混凝土梁的抗冲击行为。采用高速摄像机记录了各试件在冲击过程中裂缝的发生、发展直至破坏的全过程。与静力荷载下对比试件及冲击下无腹筋梁裂缝形态明显不同,在冲击荷载下本研究中配箍钢筋混凝土梁的裂缝分布出现随冲击能量的提高向冲击点局部集中的明显趋势,在较高能量下梁在冲击点附近发生剪切破坏。详细分析了冲击力、支座反力和位移时程曲线以及冲击力-位移曲线和支座反力-位移曲线的特征。为了分析冲击过程中梁的惯性力分布特点,采用大量程加速度计对冲击过程中沿梁长度方向不同位置的加速度响应进行了测量,由于惯性力的影响,梁的剪力分布发生明显改变。通过分析惯性力对梁的冲击响应的影响,对梁的抗冲击承载力的代表值进行了讨论。In order to further understand the shear-resistant behavior of RC beams under impact loadings on the basis of the previous study on the impact-resistant behavior of reinforced concrete （RC） beams without shear-resistant stirrups, falling-weight impact tests on a group of simply-supported RC beams with stirrups were carried. The effects of impact mass, impact velocity, impact energy as well as impact times on the shear resistant behavior of RC beams were investigated. The crack initiation, propagation and the failure patterns of the specimens were recorded using a high-speed video camera. Obviously different from the crack patterns of the specimens under static loads and the specimens without stirrups under impact loadings, cracks of the specimens with stirrups under impact loadings tend to concentrate at the mid-span and fail in shear with the impact energy increasing. The characteristics of the time histories of impact forces, reaction forces and displacement, the impact force versus displacement curves, the reaction force versus displacement curves were described in details. In order to investigate the distribution of the inertia force, accelerometers were employed to measure the acceleration responses at different positions along the length of the beams during impact. Compared with the specimen under static load, the specimens under impact loadings show different shear distribution due to the inertia effect. By analyzing the effect of inertia force on the impact response of specimens, the representative values of impact-resistant capacity of RC beams under impact loadings were discussed.

关 键 词：钢筋混凝土梁 抗冲击行为 裂缝形式 裂缝发展 惯性效应 抗冲击承载力 剪力分布 

分 类 号：TU375.1[建筑科学—结构工程]