Experimental study and numerical analysis on heavy-duty cast steel universal hinged supports for large span structures

Heavy-duty cast steel universal hinged supports are gaining increasing usage in modern large-span structures, offering extremely large individual load carrying capacity and universal rotation ability which is preferable to release temperature effects and to improve force conditions of lower structures. This paper presents a full-scale experimental study and elastic-plastic finite element (FE) analysis on the performance of an innovative heavy-duty cast steel support. The support is composed of three main components, i.e. an upper one, a lower one and an intermediate rotation pad. External loads are designed to be passed and transferred through the contact interaction of the three casting parts. The support studied in this paper is expected to possess a higher capacity than existing supports while having the ability of universal rotation under heavy loads. Three full-scale static experiments corresponding to three typical load cases (i.e. tension-shear load case, compression-shear load case, and sheartension load case, respectively) have been carried out employing a multifunctional loading device. A three-dimensional FE model was developed using the commercial software ANSYS, considering the contact behavior between the support components and accounting for both material and geometrical nonlinearities. The model was validated against the experimental results reported in this paper. The performance of this support was evaluated in accordance with a Chinese national code 'Technical specification for application of connections of structural steel casting (CECS 235:2008)'. This study concluded that this type of support performs well and that it could be used for realistic applications.