栓钉连接件锈蚀后静力性能和抗疲劳性能的试验研究

Experimental study on static and fatigue behaviors of stud connectors for composite beams after corrosion

通过15个标准试件的推出试验,研究栓钉连接件锈蚀后抗剪承载力、变形能力和疲劳寿命的变化规律。按照锈蚀位置和锈蚀量的不同将试件分组,首先采用电化学快速锈蚀试验的方法模拟可能的锈蚀情形,然后对锈蚀后的试件进行静力试验和疲劳试验。通过与无锈蚀栓钉的试验结果对比,分析锈蚀特性参数变化对试件静力工作性能的影响。并用参数拟合的方法建立两类锈蚀栓钉连接件的抗剪承载力和荷载-滑移性能的计算模型。模型分析结果表明,Ⅰ类锈蚀使栓钉极限承载力下降很多,最大达到18%;Ⅱ类锈蚀对承载力影响不大,但对试件的变形影响较大。疲劳试验结果表明,栓钉锈蚀后其疲劳寿命会有一个明显的下降,当栓钉锈蚀率达到20%左右时,其疲劳寿命下降高达40%。

Fifteen push-out specimens of stud connectors were tested to investigate the developing trends of their shearresistant capacity, shear stiffness, load-slip behavior, and fatigue life after corrosion. The possible corrosion conditions are firstly simulated by accelerated deterioration using galvanostatic method, which are categorized into four groups based on corrosion locations and mass loss. A series of static loading experiments and fatigue tests on such corroded specimens were carried out. By comparing the test results with those of the specimens without corrosion, the influences of different corrosion levels on the static behavior of components were addressed. Analytical models of shear capacity and load-slip performances under two corrosion conditions were finally given by parameter fitting method. It can be concluded that the shear capacity of studs with type I corrosion shows a significant decrease with a maximum value of 18% ; however, with type II corrosion has more influence on deflection behavior than the loading capacity. The fatigue test results show that the fatigue life of the studs decreases significantly after corrosion; for instance, the fatigue life decreases almost 40% when the corrosion rate is about 20%.