A Study Of Vertically-Loaded Local Transfer RC Joint From Inclined Column To Wall With Finite Element Method

Most of the past research measure about the capability of inclined-column local transferring structure focused on experiment of vertical loading. However, as one of the key points of a high-rise structure, this subject deserves further detailed research based on multiple methods. So in this paper, on the basis of existing experiments results, an comparison is made between the results of nonlinear FEA about inclined-column local transferring structure subject to vertical load using ANSYS and the results of experiments, the comparison contains the appearing and development of crack and crush of concrete, the stress in the concrete of the transferring beam, the stress of the bar in the beam and the strain distribution of the shear wall. The reliability of the application of ANSYS on complex RC joint is evaluated. Then parameters such as the strength of concrete and the angle of inclined column are changed for further analysis whose purpose is to find how and on which degree the change of the parameters influence the mechanical behavior of the structure.In this paper we use the famous ANSYS program, which is extensively used by scientists and engineers. The concrete material is simulated by using the built-in element SOLID65 and CONCRE material definition. The SOLID65 is a hexahedron element with 8 nodes, in the element reinforcement material can be smeared in 3 directions, which is the way of model the reinforce bars in the wall because of their uniformly distribution. Combined with CONCRE, SOLID65 is used to simulate crack and crush of brittle materials like concrete by adopting William-Wamke criteria. LINK8 element is used to model the steel reinforce bar except in the wall. LINK8 can only transfer axial force and has no volume. The stress-strain relationship is defined by adopting MISO model using points attained from the modified Kent-Park model, which is used for its simulation of the increase of concrete strength subject to stirrup confinement. The steel material of the bar is simulated using 2-line BKIN model. No bonding-losing effect is considered in the model.The comparison between the nonlinear FEA and experiment results showed that the two are compatible in different respects such as stress distribution, cracks emergence and development, load transferring path and the final breakage status.Further analysis showed that concrete strength increase will put the structure under better mechanical condition. To increase the height of the inclined column will reducethe load transferring portion of main column, and even the vertical strain distribution in the wall, which is definitely an advantage for the structure. Proper concrete strength and inclined column height, with proper construct measure focus on the mechanical behavior of special position of the structure, will lead to an optimized inclined column transferring structure, whose superiority then is showed by reduced transferring beam height and more usable space.