Experimental Research On Deformation Limits Of RC Beam And Column

RC beams and columns are the most common components for weight-bearing and resistance to lateral force of structures,their deformation performance is of great importance on seismic performance for the whole structure.The performance-based seismic design method in China’s current seismic code doesn’t provide systematic quantitative deformation performance index for RC beam and column,The codes is unable to assess components’ performance in the elastic-plastic state in detail.It limits the engineers to establish the concept of forcedeformation-damage relationship which corresponded to each other.The theory research of Qi Yongle in our institude put forward a set of quantitative assessment index for RC beams and columns.To further improve the previous study and back it up,the paper indicator an experimental study including the following aspects:(1)Code-based and typical-project-representative specimens of 9 beams and 12 columns are designed and tested under cyclic loading.Detailly records the test process including each loading state of damage and the load-displacement relationship with damage imformation.Concludes the relative position of all phenomena and its skeleton curve.(2)Define and discuss the failure modes of RC beams and columns.Verify and update Qi Yongle’s failure criterion,make it more simple,practical with high accuracy rate.(3)With the reference of domestic and foreign documents,5 failure states are given to describe damage state of RC beam and column.That is intactness, minor damage,light medium damage,medium broken and severe broken.Proposing the method to define the performance limits based on skeleton curves and confirming that the method and the experimental phenomenon are in very good correspondence.Then have a univariate analysis for performance limits,confirm that axial-load ratio,shear and stirrup ratio,shear stress levels are the main parameters that affect the performance limits a lot.(4)Combined with the pre-research of Yang Cheng and Guan Zhuliang.Analysis the performance evaluation of Qi Yongle’s previous study QYL and propose the updated index namely QYL-X.Using 4 sets of index evaluation method(QYL、QYL-X、ASCE、EC8)to evaluate and assess the spaciments.Then compare and analysis the difference of this four methods,demonstrating the effectiveness of QYL-X.