考虑腹板斜裂缝的钢筋混凝土梁剪切变形测试分析

发布时间：2018-04-28 15:56

本文选题：桥梁工程 + 应变测量装置　；参考：《长安大学学报(自然科学版)》2015年04期

【摘要】：为研究腹板斜裂缝对钢筋混凝土梁剪切变形的影响程度,设计制作了以大标距机械式应变计为基础的框格应变测量装置,并通过模型试验等手段开展了测试与分析。试验采用1组小剪跨比混凝土工字梁试件,有等高度和变高度2种截面形式;在每个试件的腹板外侧,布置了5个框格应变测量装置,通过测量每一框格5个杆件的应变,应用理论模型推算出不同位置处框格的弯曲应变和剪切应变,实现斜裂缝开展前后应变的连续观测。研究结果表明:框格测试装置能实现梁体剪切变形与弯曲变形精确分离;薄腹梁腹板开裂后,剪切变形在总变形中的比例超过50%,箍筋屈服时,剪切变形可达到总变形的90%左右;配箍率与有效抗剪高度对开裂后剪切变形有显著影响;应用框格大标距的测试方法,有助于推动弹塑性极限状态下混凝土梁抗剪刚度的深入研究。
[Abstract]:In order to study the influence of inclined cracks of web plate on shear deformation of reinforced concrete beams, a frame strain measuring device based on mechanical strain gauge with large distance is designed and manufactured, and the test and analysis are carried out by means of model test and so on. A group of small shear span ratio concrete I-beam specimens with equal height and variable height were used in the experiment. On the outside of the web plate of each specimen, five frame lattice strain measuring devices were arranged, and the strain of each frame and 5 bars was measured. The bending strain and shear strain of frame lattice at different positions are calculated by using the theoretical model, and the continuous observation of the strain before and after the development of oblique crack is realized. The results show that the frame lattice testing device can accurately separate the shear deformation from the bending deformation of the beam, the shear deformation in the total deformation is more than 50% after the web of the thin web is cracked, and when the stirrups yield, the shear deformation can reach about 90% of the total deformation. The ratio of hoop and the effective shear height have a significant effect on the shear deformation after cracking, and the application of the test method of large frame spacing is helpful to the further study of the shear stiffness of concrete beams under the elastic-plastic limit state.
【作者单位】：东南大学交通学院;东南大学土木工程学院;
【基金】：江苏省交通科学研究计划项目(2010Y12)
【分类号】：U441

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