Failure Criterion Of Punching Shear And Grid Beam Elements For Reinforced Concrete Slab Column Structures

In the reinforced concrete slab column structure, the experimental study, theoretical analysis and numerical simulation are the common research methods because of the complicated stress of slab column joint. The numerical analysis method of traditional plate column structure or component is based on the solid element modeling analysis,it bring some limitations to the practical application in the machine time and the complexity of modeling. Therefore, this paper establishes modified 3D grid beam model.Using model to carry out numerical analysis based on OPENSEES. Through a large number of numerical analysis, the simulation results are in good agreement with the test results. The rationality and reliability of the model are verified. Provide a theoretical reference for the design of the plate column joints and specification revision.(1) Combinating chinese code GB 50010-2010 with five foreign design codes(ACI318-08,EC4,CSA A23.3-04,DIN 1045-1,JSCE 15), and analsis contrastively with examples. The results show that the results are different, and impact of the critical section perimeter and the ratio of reinforcement are considered in China codes.(2) This paper establishes modified 3D grid beam model and the key parameters of the model are verified and validated. Nonlinear finite element analysis of 15 reinforced concrete slab column middle joints is carried out based on OPENSEES. The simulation results are in good agreement with the test results. The rationality and reliability of the model are verified and then carry out parameter analyses of the ratio of reinforcement,concrete strength and deformation distribution.(3) The failure criterion based on critical shear crack theory that is presented by Muttoni is verified. A total of 39 plate column middle joints from experiments of Elstner and Stefanno are compared and analyzed, and compared with China codes. Chinese code is suggested to be revised and improved about calculation content of punching shear bearing capacity referring to critical shear crack theory and relevant parameters.