圆钢管约束型钢高强混凝土短柱的受压性能试验研究及有限元分析

Experimental study and finite element analysis on compressive behavior of circular tubed steel-reinforced high-strength concrete short columns

文章对6根圆钢管约束型钢高强混凝土短柱进行受压力学性能的试验研究,重点探究不同的偏心距及径厚比对试验柱力学性能的影响。结果表明,内部型钢与外部钢管的双重约束效应能够有效改善高强混凝土的脆性并显著提高柱极限承载力,钢管的约束作用随着径厚比的减小而显著增加,即径厚比越小,试件的延性越好,极限承载力越高,但试件延性与承载力的提高幅度均与偏心距呈负相关。在此基础上,利用ABAQUS软件对试验结果进行了有限元分析,数值模拟结果与试验结果吻合较好,具有较高的精确度,而后通过相同的建模方法对偏心距、径厚比、钢材强度、混凝土强度等因素进行系统的参数分析,发现减小试件的径厚比并增加混凝土的强度将显著提高试件的极限承载力与延性,但提高幅度将随着偏心距的增大而减小,最后根据有限元参数分析结果提出相应的实用设计建议。

In this work,six circular tubed steel-reinforced high-strength concrete(CTSRC)short columns are tested under compression,and the effects of eccentricity and diameter-to-thickness ratio on the tests are particularly investigated.The test results show that the dual constraints from the internal steel and the external steel tube can effectively improve the brittleness of the high-strength concrete and significantly increase the load-bearing capacity of the test specimens;the constraint effect of the steel tube shall be increased significantly with the decrease of the diameter-to-thickness ratio,that is,the smaller diameter-to-thickness ratio may lead to the better ductility and the higher ultimate capacity;however,the improvement extents of ductility and load-bearing capacity of specimens shall be negatively correlated to the eccentricity.On this basis,the ABAQUS software was firstly used to verify the test results,and it was found that the numerical results were in good agreement with the experimental results.Furthermore,the parametric study was conducted by using the FE method to provide more experimental results for the test database.Systematic analyses were performed on some parameters,including eccentricity,diameter-to-thickness ratio,steel strength and concrete strength.It was found that the concrete strength and diameter-to-thickness ratio are the two most important factors affecting the enhancement of load capacity and ductility,but the improvements of the strength and deformation may decrease with the increment of eccentricity.Finally,some suggestions for the columns in practical design were proposed based on the finite element analysis.