| With the development of energy dissipation technology in China,metal dampers are widely used in engineering practice due to the advantages of economic cost,convenient material extraction and clear working mechanism.However,in view of the cases that most of the existing metal dampers achieve energy dissipation by bending and shearing of steel plate,the energy dissipation efficiency of the damper is low,the size is large,which are difficult to be applied to the critical vertical bearing parts with serious earthquake damage such as the concrete column end or the bottom of bridge pier due to their low energy dissipation efficiency and large size.Therefore,an energy dissipation damper is proposed based on the tensile and compression yielding of the perforation steel plate,and carries out corresponding research on it,the main work completed is as follows:(1)The existing achievements on metal dampers are summarized,the basic structure and composition of steel plate tensile yield type energy dissipation dampers are elaborated,the working principle of steel plate tensile-compression yield type energy dissipation dampers is clarified,and a new and reliable energy dissipation dampers outside the plane constraint method is studied.The calculation method of elastic stiffness and effective stiffness of damper is introduced by means of damper recovery force curve model.(2)Five energy dissipation damper specimens are designed,and the mechanical properties of the specimens are tested by low cycle loading test method to study the hysteretic and fatigue properties of the damper.The results show that:when the out-of-plane stiffness provided by the confinement steel plate and steel bar as the core plate is large,the damper is full of hysteresis curve and has excellent energy consumption ability;the damper is loaded in cycles with different design displacements,and the fatigue performance meets the specification design requirements;under the fatigue and hysteresis reloading mode,the failure of damper is caused by the crack fracture of the core plate long strip hole,and compared with the hysteretic specimen,the damage to the core plate of the fatigue specimen accumulates more,and the fractured parts when the failure occurs are more than those of the hysteretic specimen.(3)Through the ABAQUS finite element software,the energy dissipation damper based on the tension and compression yielding of steel plates proposed in this paper is analyzed and simulated,the results show that:the hysteresis and fatigue curve obtained by finite element analysis and the hysteresis obtained by the test are basically consistent with the fatigue curve,and the finite element modeling method in this paper is more reliable;The stress contours of hysteretic and fatigue specimens simulated by finite element method is consistent with the failure of specimens after loading,both are the middle of the energy consuming core steel plate after perforating;The fatigue performance index of the fatigue specimen simulated by finite element method is very close to the experimental data,with the maximum error less than 10%.through this modeling method,the force characteristics of the energy dissipation damper can be realized.(4)The finite element method is used to analyze the changes of mechanical properties of energy dissipation damper when the main structural parameters of energy dissipation core steel plate are different.and according to the structural form of energy dissipation core steel plate,the theoretical calculation formulas of mechanical performance indexes such as theoretical initial stiffness,theoretical yield load and theoretical yield displacement are deduced and verified by ABAQUS finite element analysis method.The results show that the theoretical calculation methods of mechanical properties of energy dissipation core steel plate are more reliable. |
