Theoretical And Experimental Research On Dissipation Of Shear Panel Dampers Made Of Low-Yield-Point Steel

Earthquake is one of sudden natural disasters to endanger people’s lives and property. When suffering the earthquake, traditional structure mainly relies on its own behavior to store and dissipate earthquake energy, and the structure may be damaged devastatingly after the earthquake. Hence, some isolation device or damping component inserted into the structure to change the dynamic characteristics and reduce dynamic response of the structure can effectively enhance the seismic behavior of structure. With the low yield strength, good plastic deformation, stable hysteresis performance and superior low cycle fatigue performance, the low-yield-point steel(LYP) can be made into the energy dissipation damper, and it can enter the plastic stage earlier than main structure to dissipate energy. The paper carries out experimental, simulative and theoretical researches of shear panel dampers made of Low-Yield-Point steel, and main contents are as follow:(1) Through the quasi-static monotonic loading test, the Young modulus, yield strength and ultimate strength of Low-Yield-Point steel are obtained and the constitutive relation is determined. To obtain the cyclic stress-strain curve and hardening parameters, the low cycle fatigue experiments are conducted.(2) Low cyclic load experiment of four non-stiffener low-yield-point steel shear panel dampers(NS-LYPSPD) is conducted to investigate the hysteretic behavior. The simulation of four NS-LYPSPD under low cyclic load is conducted with the finite element program ABAQUS. The study shows that: the most ideal failure mode is core plate center damage which can guarantee the full energy dissipation of core plate. The deformation capacity and energy dissipation capacity of damper is related to loading history, the energy dissipated under increasing amplitude displacement loading and constant amplitude displacement loading is more than random amplitude displacement loading. And the result simulated by ABAQUS is close to result of the experiment, including the deformation, stress distribution, hysteretic curve, horizontal bearing capability, the degradation pattern of stiffness, etc.(3) With the concept of pseudo skeleton curve, based on double linear constitutive relation and R-O cyclic constitutive relation, four damping force models of shear panel damper coupling isotropic hardening with kinematic hardening are proposed. The models are proved to be effective compared with experiment hysteretic curve. The result shows that R-O double linear combination model and coupling R-O model have high degree of agreement with the test curve.(4) A new type of buckling-restrained stiffener low-yield-point steel shear panel damper(S-LYPSPD) is experimented under low cyclic load, and compared with NS-LYPSPD. The result shows that the stiffener limits the out-of-plane deformation of core plate, improve the ductility of the damper and delay the destruction of the damper.The preliminary research proves that low-yield-point steel shear panel damper has an excellent energy dissipation performance, and it has a great application foreground in structure control field and worth a further study.