AH36钢含裂纹板与加筋板低周疲劳裂纹扩展试验

Experimental Study on Low-cycle Fatigue Crack Propagation of Cracked Plate and Stiffened Plate Based on AH36 Steel

对AH36钢含裂纹板与加筋板试样,在恒幅和变幅拉伸循环载荷下进行裂纹扩展试验,探讨有无加强筋以及在基本循环中插入单个拉伸过载情况下的低周疲劳寿命及裂纹扩展速率的规律,结果表明,AH36钢对应力比效应较敏感;恒幅循环载荷下,加强筋能有效增大疲劳寿命;在一定范围内过载比越大,过载迟滞效应也越明显,过载的迟滞效应可有效减小裂纹扩展速率。

The behavior of crack propagation under constant amplitude and variable amplitude tensile cyclic loading was studied for the crack plate and stiffened plate specimens of AH36 steel.The rule of low cycle fatigue life and crack propagation rate under the condition of single tensile overload was inserted into the ring.The test results showed that the AH36 steel is sensitive to the force ratio effect;the reinforcement can effectively increase the fatigue life under the constant amplitude cycle load;the greater the overload ratio in a certain range,the more obvious the overload retardation effect is,and the overload retardation effect reduces the crack propagation rate effectively.