冲击作用下钢筋混凝土深梁动力性能试验研究

发布时间：2019-04-15 22:15

【摘要】：为了探讨在冲击荷载作用下钢筋混凝土深梁的动力性能,利用大型落锤试验机对两组具有不同静载破坏特性的简支钢筋混凝土深梁进行了不同冲击速度下的动力性能试验研究,并考虑了二次冲击的影响。通过对高速摄像机所记录的各试件在冲击过程中裂缝的发生、发展直至试件破坏的全过程进行分析和不同荷载下裂缝形态差异的对比分析,表明不同的冲击速度下试件裂缝的发生、发展过程及裂缝形态表现出明显的差异,二次冲击下的主要裂缝基本遵循一次冲击产生的裂缝路径发展。详细分析了冲击力和跨中位移时程曲线以及冲击力-跨中位移曲线的特征,发现冲击力峰值与冲击速度、最大跨中位移和跨中残余位移与冲击速度在不发生严重剪切破坏时均满足近似线性关系。分析还表明,具有较好延性的深梁具有更好的抗冲击性能。最后,通过对比分析冲击力、支座反力和惯性力时程曲线,得出采用冲击力峰值和支座反力峰值作为深梁的抗冲击承载力均不准确的结论。
[Abstract]:In order to investigate the dynamic performance of reinforced concrete deep beams under impact load, two groups of simply supported reinforced concrete deep beams with different static load failure characteristics were tested under different impact speeds by means of a large-scale drop hammer testing machine, and the dynamic performance tests were carried out on two groups of simply supported reinforced concrete deep beams with different static load failure characteristics. The influence of secondary shock is considered. Through the analysis of the whole process of crack occurrence and development up to the failure of the specimen recorded by the high-speed camera during the impact process, and the comparative analysis of the difference of crack morphology under different loads, It is shown that there are obvious differences in the occurrence, development process and fracture morphology of the specimens under different impact speeds, and the main cracks under the secondary impact basically follow the crack path caused by the first impact. The characteristics of the impact force, the time history curve of the mid-span displacement and the impact force-span middle displacement curve are analyzed in detail, and the peak value of the impact force and the impact velocity are found. The maximum mid-span displacement, mid-span residual displacement and impact velocity are approximately linear in the absence of severe shear failure. The analysis also shows that the deep beam with better ductility has better impact resistance. Finally, by comparing and analyzing the time-history curves of impact force, bearing reaction and inertia force, it is concluded that it is not accurate to use the peak value of impact force and the peak value of support reaction as the bearing capacity of deep beam.
【作者单位】：湖南大学土木工程学院;湖南大学建筑安全与节能教育部重点实验室;海南大学土木建筑工程学院;
【基金】：国家自然科学基金重大研究计划重点项目(90715033);培育项目(91015007)
【分类号】：TU375.1

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