【摘要】 对HRB400 Ⅲ级抗震钢筋的低周疲劳性能进行了研究。采用轴向应变控制方法,在岛津电液伺服疲劳试验机上测定了试验钢低周疲劳过程中的循环应力响应特征及循环应力与应变的关系;通过拟合Basquin公式和Coffin-Manson公式,获得了试验钢的低周疲劳寿命预测公式。断口扫描发现,试验钢裂纹起源于试样表面,通过不断扩展形成微裂纹,再连接成宏观裂纹,最终导致材料断裂。更多还原

【Abstract】 Low cycle fatigue properties of anti-seismic HRB400 grade Ⅲ reinforcing steel bar were investigated.The fatigue tests were conducted on Shimadzu servo-hydraulic testing machine.The tests were run under uniaxial tension-compression loading with total strain control.The cyclic stress response characteristics and relationship between cyclic stress and strain of the steel were measured.The strain-life data from the axial tests were used to derive suitable Coffin-Manson parameters for the test material.The scanning electron microscope(SEM)micrographs reveal that the fatigue cracks initiate from the surfaces of samples.Due to the propagation and connection of the micro-cracks,macro-cracks form and fracture occurs eventually.更多还原