Research On Deformation Limits Of RC Frame Beam Based On Material Strain

Performance-based seismic design method can not only propose the capacity requirement, but also set a desired deformation limit according to the needs of the owner to design the structure. It is the direction of the developing of the seismic code for various countries.Actual earthquake show that there are part of reinforced concrete structure were damaged because of the destruction of frame beams, plastic hinge are formed in the end of frame beam. Therefore, as the important energy consumption component, it is very important to design the RC beams to have good seismic performance in the premise of ensuring safety and reducing economic loss. In this paper, systemic analysis about the impacts of facts on the seismic performance of RC beam is carried out. A classification criterion of RC beam failure mode is proposed based on collected experimental data,the criterion contained two parameters, that are shear span ratioand flexure shear ratio.The reliability and feasibility of the FE model and parameters are verified by simulating 17 RC beamtestspecimens using ABAQUS finite element software, based on this a set of RC beams are designed to do FE analysis and plastic performance limits of RC beam under six performance stages, such as First-yield, Serviceability, Light mid-range damage, Damage control, Life safe and Collapse. The main contents in this paper are as follows:1. Summarize the RC beam seismic performance experimental researches done by internal and abroad scholars, and systemically analysis about the impacts of facts such as shear span ratio, concrete strength, reinforcing conditions on the capacity, deformability and failure mode of RC beam.2. Study the classifications of RC beam failure mode. Analysis the collected experimental data of 80 RC beams and propose a new RC beam failure mode classification criterion which is contained two parameters that are shear span ratioand flexure shear ratio.3. Simulate 17 RC beam specimens tested by scholars using ABAQUS finite element software. Comparison of load-deformation curve and failure modes of the specimens between the calculated result and experimental result is done, finding that the calculated result agree well with the experimental result. It is indicated that the calculated result of RC beam simulated by using ABAQUS is credible when suitable material constitutive models and FE parameters are selected. 4. On the basis of the accuracy and feasibility of FE method, 224 RC beams are designed as the shear span ratio, reinforcement ratio,stirrup ratio and (?), Damage plasticity concrete model is used forconcrete, and perfect elastic-plastic model is used for reinforcing bars. Analysis about the impacts of the four parameters on the plastic deformability and failure mode of RC beam are conducted. The plastic deformation limits of RC beam components in different coditions are proposed based on the analyzed result, it can provide corresponding reference for performance-based seismic design of RC beam.