Seismic Performance Research On Fabricated ECC Shear Wall With Small Shear Span-to-depth Ratio

Engineered cementitious composites(ECC)is a new type of fiber reinforced cement composites which exhibits significant tensile strain hardening and fine multiple cracking behavior.It has been proved that ECC can effectively improve seismic performance of structural members,especially for those areas subjected to large deformation and shear load.Shear walls with small shear span-to depth ratio are widely used in the modern high-rise buildings,where shear failure is easy to occur under earthquake action.Use of ECC material in this kind of structures has a strong application prospect and practical significance.Experimental verification,numerical simulation and theoretical analysis are combined in this paper to systematically investigate the seismic performance of precast ECC shear walls with small shear span-to-depth ratio.The main research contents and conclusions of this paper are as follows:In Chapter Two,the plastic damage model of ECC shear members in ABAQUS is established.Meanwhile,experimental study on ECC members with small shear span ratio is carried out in order to verify the reliability of the finite element method.In chapter Three,the finite element simulation method of precast shear wall is verified by the existing RC shear wall test.The finite element simulation of ECC precast shear wall is carried out,the result of which shows that ECC can effectively improve the failure mode of shear walls with small shear span ratio.Based on above research,parameter analysis on precast ECC shear wall is finished by finite element simulation in chapter Four.The analysis results indicate that with the decrease of axial compression ratio and the increase of shear span ratio and hoop ratio,the ductility and energy dissipation performance of shear walls are gradually enhanced,while the efficiency of different parameters is different.In Chapter Five,a theoretical calculation formula for ECC shear wall with low shear span ratio is proposed on the base of the classical MCFT model.The accuracy of the formula is verified by comparing the calculations with test results,which means it can be used to estimate bearing capacity and failure mode.