高强混凝土框架柱截面尺寸效应的变化规律

Variation Rules of Cross-section Size Effect of High-strength Concrete Frame Column

根据收集的117根高强混凝土框架柱在固定轴向荷载和水平反复荷载作用下的试验结果,用MATLAB软件编制的程序计算出试验柱的骨架曲线、屈服位移和屈服荷载、最大位移和最大荷载、极限位移和极限荷载、延性系数、弹性刚度、强化刚度、最大刚度和退化刚度、各滞回环面积和累计滞回环面积,并用ORIGIN软件一元线性拟合出各参数与截面面积或截面高度之间的关系式,然后根据ORIGIN软件回归结果分析了截面尺寸对框架柱承载力、延性、刚度及耗能的影响规律。结果表明:随着截面面积的增大,名义弯矩逐渐降低,试件承载力最大试验值与按照规范计算的最大承载力的比值逐渐减小,框架柱的延性逐渐降低;随着截面高度的增加,框架柱的极限位移角逐渐降低,框架柱的强化刚度、退化刚度及最大刚度与弹性刚度的比值均逐渐增大,框架柱的平均耗能系数逐渐降低。

According to the collected test results of 117 high-strength concrete frame columns under fixed axial load and horizontal repeated load, the skeleton curve, yield displacement and yield load, maximum displacement and maximum load, ultimate displacement and ultimate load, ductility coefficient, elastic stiffness, strengthening stiffness, maximum stiffness and degradation stiffness, area of each hysteretic loop and accumulated hysteretic loop area of the test column were calculated by the program compiled by MATLAB software. The relationship between them and section area or section height was fitted linearly by ORIGIN software. Then the influences of section size on bearing capacity, ductility, stiffness and energy consumption of frame columns were analyzed according to ORIGIN software regression results. The results show that with the increase of section area, the nominal bending moment decreases gradually. The ratio of the maximum bearing capacity of specimens to the maximum bearing capacity calculated according to the code decreases gradually, and the ductility of frame columns decreases gradually. With the increase of section height, the ultimate displacement angle of frame columns decreases gradually, the strengthening stiffness, degradation stiffness and ratio of maximum stiffness to elastic stiffness of frame columns increase gradually, and the average energy dissipation coefficient of frame columns decreases gradually.