Numerical analysis of a prefabricated concrete beam-to-column connection with bolted end plates

Abstract

Precast concrete structures have been widely used in China in recent years because of the obvious advantages in construction speed, labor saving and quality control. Many experimental and numerical studies have been performed to investigate the seismic behavior of the precast concrete structures. However, the numerical analysis on prefabricated concrete beam-to-column connection with bolted end plates (PCC) under cyclic loading is still limited. Therefore, in this paper, the developed finite element models (FEM) were established to further study the seismic performance of the PCC specimens. The sensitivity analysis were conducted to ensure the reliability and validity of the FEM. Then, the FE models of the typical specimens were validated by test data such as failure modes, hysteresis curves and steel strain. Parametric analysis was carried out to investigate the effect of the end plate thickness, preload of bolt, concrete strength, etc. The key parameters affecting the seismic behavior of the connections were obtained. Eventually, based on the numerical simulation results, the law between the responses of the connections and the key parameters was determined quantitatively by response surface methodology. According to the yield line theory, the theoretical formula on the bending capacity of the connection with thin end plate was derived. Meanwhile, the formulas on the bending capacity of the unbonded prestressed concrete beam were also obtained. The results indicated that the bearing capacity and initial stiffness of the connection were improved with the increase of end plate thickness and bolt preload. The steel box significantly enhanced the shear capacity of joint region of the PCC specimens. Although the bending capacity of the beam can be improved by increasing the concrete strength, high strength concrete significantly reduced the ductility. The calculated value of the connection matched well with the test or simulation data which may provide a reference for predicting the bending capacity of specimens with different failure modes in subsequent studies.