钢筋混凝土梁循环加载时Kaiser点的确定方法

摘要

对常用的几种Kaiser点确定方法进行了比较分析,从参数的选用、判断方法等方面指出了各方法的优点及不足之处.通过对钢筋混凝土梁进行循环加载试验,分析各级荷载下的AE累积计数N与荷载F关联曲线的特点,发现在lnN-F半对数坐标上,关联曲线的拐点坐标具有明显的变化规律,可作为钢筋混凝土梁循环加载时的Kaiser点；提出了用求解曲线拐点来确定Kaiser点的方法,并利用该方法对钢筋混凝土梁受荷过程的Felicity效应进行了分析.%Several methods of determining the Kaiser point are compared. Three reinforced concrete beams are cyclic loaded,and the characteristics of the N - F curves at each load levels are analyzed. It is found that the inflection points of the N - F curves in the semi-logarithmic coordinate system (In N - F) have obvious regularity, and the inflection points can be used as the Kaiser point when the reinforced concrete beams are cyclic loaded. A new method of determining Kaiser point by calculating the inflection points is proposed and the Felicity effective of reinforced concrete beams in cyclic loading is discussed.