Research On The Dissipation Behavior Of Rib-stiffened Shear Panel Dampers Made Of Low Yield Stress Steel

As one of the most common energy dissipation absorbers in buildings,metallic dampers achieve the purpose of energy dissipation and vibration reduction through yielding deformation of metal.Materials commonly used in core energy-dissipating elements of metal dampers include low yield stress steel,lead,copper,aluminum,etc,among which,the mechanical properties of low yield stress steel are excellent: it has a very low yield point,good ductility,and shows good fatigue performance when subjected to reciprocating load;its ultimate strength is not affected by loading strain rate,and gains good impact performance and cold bending performance.In the late 1990 s,scholars at home and abroad began to study the shear plate damper made of low yield stress steel and conducted a series of tests.Based on the research status of low yield stress steel shear plate dampers at home and abroad,a new type of stiffened low yield stress steel shear panel dampers(S-LYSSPD)with transverse stiffening rib was designed in this paper,which was subjected to experimental study,finite element simulation and theoretical analysis.The research contents mainly are showed as follows:(1)The quasi-static monotonic tensile test of low yield stress steel LYP160 is conducted to determine its Young's modulus,yield point,ultimate strength and other basic mechanical properties,and obtain its constitutive relationship.(2)Three S-LYSSPD with transverse stiffening ribs are designed and manufactured.The variation law of parameters and the degradation process of damper bearing capacity are analyzed.Using finite element software ABAQUS,a series of full-scale damper model are established to simulate the cyclic loading process of the test.The results show that shear tear break at the center of the web is the most ideal failure mode in which ensures the full energy dissipation capacity of the web.Finite element analysis can accurately simulate the stress and strain distribution of S-LYSSPD,and the obtained hysteretic loop curve,the law of horizontal bearing capacity and stiffness degradation are in good agreement with the test results.(3)According to Timoshinko's plate and shell theory and elastic stability theory,This paper considers a variety of boundary conditions in order to propose the expression of the critical elastic buckling force of plate subjected to in-plane shear force given,and then the relationship between the ratio of plate width to thickness and the critical buckling force are determined as well.The results show that the buckling of the plate is affected by three factors,which is the ratio of width to thickness,the constitutive parameters of the plate(elastic modulus,shear yield stress)and boundary conditions.It is the stronger restraint,smaller ratio of width to thickness and greater shear yield stress that can reduce the buckling of the plate and make full use of its energy dissipation performance.Combined with test results,finite element simulation results and theoretical models,it can be improved that the adoption of anti-buckling stiffener can effectively alleviate the out-of-plane buckling of the plate to improve the energy dissipation capacity of the web,and also make full use of steel,delaying the damage of the damper.The low-yield-steel shear plate damper reinforced by anti-buckle stiffener is worthy of further study and application.