焊接钢筋网疲劳性能试验研究

Experimental Study on Fatigue Properties of Welded Steel Fabric

为研究桥面铺装层冷轧带肋钢筋(CRB550)焊接网的疲劳性能,分别对焊接钢筋网母材试件以及带焊接节点的试件在不同应力水平下进行高周疲劳试验,并在不同应变幅下进行低周疲劳试验。分析了母材试件和带焊接节点试件的疲劳性能,循环硬化软化特性,滞后回线及循环弹性模量衰减规律,并对断口形貌进行扫描电镜分析。得到了焊接钢筋网的S-N曲线以及P-S-N曲线,并进行疲劳可靠性分析。研究表明:母材试件的疲劳寿命明显高于带焊接节点试件的疲劳寿命,并通过扫描电镜证实了焊接对材料有明显损伤,焊接是影响寿命的主要因素;母材试件及带焊接节点试件均出现明显的循环软化特性,且循环软化规律及衰减程度基本相同;循环弹性模量随着循环次数的增加缓慢降低,最后阶段迅速降低至试件断裂。

In order to study the fatigue performance of cold rolled ribbed reinforcement(CRB550) welded mesh for bridge deck pavement,high cycle fatigue tests were carried out on the base metal of welded mesh and specimens with welded joints at different stress levels,and low cycle fatigue tests were carried out at different maximum strains.The high cycle fatigue properties,cyclic hardening and softening characteristics,hysteresis loop and attenuation law of elastic modulus of base metal specimens and specimens with welded joints were analyzed,and the fracture morphology was analyzed by SEM.The S-N curve and P-S-N curve of welded reinforcement mesh are obtained,and the fatigue reliability is analyzed.The results show that the fatigue life of the base metal specimen is significantly higher than that of the specimen with welded joints.The obvious damage of welding to the material is confirmed by SEM.Welding is the main factor affecting the life;Base metal specimens and specimens with welded joints have obvious cyclic softening characteristics,and the cyclic softening law and attenuation degree are basically the same;The cyclic elastic modulus decreases slowly with the increase of the number of cycles,and rapidly decreases to the fracture of the specimen in the last stage.