无檩空间网格结构装配式螺栓球柱节点高温受压性能研究

A Study on the Compressive Bearing Capacity of Prefabricated Bolted Ball-Cylinder Joints at Elevated Temperatures

为了填补螺栓球柱节点在高温受压承载性能研究方面的空缺,借助有限元分析软件ABAQUS开展研究。首先,在校核模型可靠性的基础上,进一步提出了更符合实际情况的节点模型;其次,通过147个模型算例探究节点的破坏机理和各关键参数对节点受压承载性能的影响;最后,推导出节点的高温受压承载力公式。研究结果表明:提出的节点模型不仅更符合实际情况,而且对螺栓球柱节点受压性能的评估也更加保守和安全;当温度在300℃以内时,节点的初始刚度和承载力变化不明显,当温度大于300℃时,节点的初始刚度和承载力出现显著下降;高温下钢材屈服强度的折减系数可以较为准确地预测节点高温受压承载力的变化。

In order to study the compressive bearing capacity of bolted ball-cylinder joints at elevated temperatures,the finite element analysis software ABAQUS is used in this paper. Firstly,for checking the reliability of the model,a more practical joint model is proposed. Secondly,147 model examples are used to evaluate the failure mechanism and the influence of key parameters on the bearing capacity of the joint. Finally,a formula of compressive bearing capacity at elevated temperatures is proposed. The results show that the proposed joint model is not only more consistent with the actual situation,but also more conservative and safe for evaluating the compressive performance of bolted ballcylinder joint. When the temperature is less than 300 ℃,the initial stiffness and bearing capacity of the joint does not change significantly. When the temperature is higher than 300 ℃,the initial stiffness and bearing capacity of the joint decreases significantly. The reduction factor of steel yield strength at elevated temperature can accurately predict the change of compressive bearing capacity of joints at elevated temperatures.