极地低温下栓钉连接件受剪性能试验研究及有限元分析

Experimental and analytical study on shear behavior of studs under polar temperature

为研究栓钉连接件在极地低温下的受剪性能,利用复叠式低温冷库、自制保温装置和电液伺服压力试验机对12个栓钉连接试件进行了推出试验,同时采用ABAQUS软件对其进行有限元分析,研究了温度、栓钉直径对低温下栓钉连接件受剪性能的影响。通过试验和有限元分析得到了试件破坏模式、荷载-滑移曲线、栓钉受剪承载力及极限滑移量,结果表明:试件在低温下出现栓钉剪断和栓钉剪断-混凝土压坏混合破坏两种破坏形式;在20～-80℃范围内,随着温度的降低,栓钉受剪承载力增大而极限滑移量减小,在-60～-80℃范围内,温度变化对栓钉连接件受剪性能的影响较小;在极地低温下,随着栓钉直径增大,栓钉连接件的受剪承载力和极限滑移量增加。采用ABAQUS软件考虑低温本构的有限元分析结果与试验结果吻合程度较高,通过试验结果拟合出的荷载-滑移曲线效果良好。

Twelve push-out specimens were tested and three-dimensional nonlinear finite element analysis was conducted to investigate the shear behavior of studs under polar temperature. The equipment included large-scale cold storage, insulation box and pressure testing machine. By changing the investigated parameters including temperatures and stud diameters, the failure modes, load-slip curves, ultimate shear capacity and slip were obtained. The results show that two kinds of failure modes including stud shear and mixed failure can be distinguished. In the temperature range from 20 ℃ to-80 ℃, the shear capacity of studs increases and the ultimate slip decreases with the decrease of temperature. In the temperature range from-60 ℃ to-80 ℃, the temperature has slighter influence on the shear behavior of studs. With the increase of the stud diameter, the bearing capacity and the ultimate slip increase under polar temperatures. By using ABAQUS software and adopting cryogenic constitutive relations, the finite element analysis results and regression curves agree well with the test results.