恒高温下钢管混凝土界面粘结性能的试验研究与有限元分析

发布时间：2018-04-19 16:24

  本文选题：钢管混凝土 + 恒高温　； 参考：《湘潭大学》2017年硕士论文

【摘要】：钢管混凝土是指钢管内填充混凝土后,钢管和混凝土同时受力的构件。其优越性能依靠钢管和混凝土的协同工作来发挥,但两种材料之间的相互作用机理较复杂。在荷载的传递过程中,钢管和混凝土共同受力与协调变形,其间的界面粘结力,尤其是抗剪粘结力发挥着极其重要的作用。由于高温使钢管和混凝土的材料性能发生劣化,另外钢管和混凝土的膨胀变形不一致等都有可能导致其界面性能发生劣化;从而使结构构件的承载性能和稳定性大大下降。目前,国内外对常温下和火灾后钢管混凝土界面性能开展了一定数量的研究,而对于火灾高温下的钢管混凝土界面粘结性能还未见相关报道。基于以上背景,本文对恒高温下钢管混凝土的界面粘结性能进行试验研究。主要工作和成果如下:(1)进行了23根钢管混凝土柱试件的恒高温下推出试验,得到了温度-时间曲线和荷载-相对滑移曲线。并分析了恒温温度、钢管径厚比、长细比等因素对平均粘结强度与荷载-滑移曲线的影响。试验结果表明,在20℃~900℃研究范围内,恒温温度对圆钢管混凝土平均粘结强度有显著的影响,平均粘结强度随恒温温度的升高先减小后增加再减小;随钢管长径比的增大而减小;随径厚比的增加,平均粘结强度增减的程度相对较小。(2)根据分析结果,确定了影响恒高温下钢管混凝土中钢管与混凝土之间粘结强度的关键因素,回归了恒高温下平均粘结强度以及峰值荷载对应的相对滑移值公式;在此基础上,得到了恒高温下钢管混凝土的界面粘结应力-滑移关系模型。将其关系模型与试验结果进行对比分析,验证了关系模型的合理性。(3)建立恒高温下钢管混凝土柱有限元模型,通过相关试验验证有限元模型的适用性与合理性。
[Abstract]:Concrete-filled steel tube (CFST) is a kind of concrete-filled steel tube, which is loaded with concrete and steel tube at the same time.Its superior performance depends on the cooperative work of steel tube and concrete, but the interaction mechanism between the two materials is complicated.In the process of load transfer, the joint force and deformation of steel tube and concrete, the interfacial bonding force, especially the shear bond force, play an extremely important role.Due to the deterioration of material properties of steel tube and concrete at high temperature, the inconsistency of expansion deformation between steel tube and concrete may lead to the deterioration of interface properties, thus the bearing capacity and stability of structural members will be greatly reduced.At present, a certain number of researches have been carried out on the interface properties of CFST at room temperature and after fire, but the bond behavior of CFST interface under fire and high temperature has not been reported.Based on the above background, the interfacial bond behavior of concrete filled steel tube (CFST) at constant temperature is studied experimentally.The main work and results are as follows: 1) the temperature-time curves and load-relative slip curves of 23 concrete filled steel tubular columns are derived at constant temperature.The effects of constant temperature ratio of diameter to thickness of steel pipe and aspect ratio on the average bond strength and load-slip curve were analyzed.The experimental results show that in the range of 20 鈩，

本文编号：1773836