高强HRB400E建筑用抗震钢筋高应变低周疲劳性能研究

Study on High Strain Low Cycle Fatigue Properties of HRB400E Reinforced Steel Bars

对V-N微合金化钢筋和余热处理HRB400E钢筋的低周疲劳性能进行了研究。采用轴向应变控制的方法测定了两种工艺下钢筋的高应变低周疲劳性能,研究了在循环载荷下材料的循环应力响应特性、循环应力与应变关系,通过拟合Hollomon公式与Coffin-Manson公式推导出微合金化与余热处理两种钢筋的疲劳寿命计算公式,并计算出Nf=100周时的循环能量吸收率Δεt·σa值。结果表明,相比于轧后余热处理工艺,微合金化能同时提高Δεt和σa值,有利于材料在地震载荷下吸收较多能量,从而提高抗震性能。

High strain low cycle properties of HRB400 vanadium-nitrogen micro-alloying and temp-core reinforced steel bars with φ25 mm and φ20 mm were respectively investigated on Instron-Model1342 fatigue test machine.Cycle stress-strain response characters of the two kinds of steel bars were used to stimulate Coffin-Manson and Hollomon formulas to calculate the fatigue life of the two types of materials.The value of Δεt·σa was estimated when Nf =100.The results show the vanadium micro-alloying ones have better fatigue properties than temp-core ones,and micro-alloying method can improve strength and toughness of the material simultaneously,which is advantageous to the absorption of more energy under earthquake loading,and improve the earthquake proof property.