传统铅阻尼器一般利用相对平动位移的变化使得铅发生塑性变形,以此消耗能量。提出一种基于中心轴转动挤压铅耗能的新型铅挤压阻尼器,可直接用于扭转耗能结构体系中(如梁柱间的相对转角等),或通过相关转换结构(如齿轮等)将常规的相对平动位移的耗能机制转换为相对转角位移的耗能模式。基于平面应变假定,以Abaqus平台建立了扭转挤压铅阻尼器的非线性有限元模型,模拟了单轴、双轴扭转铅挤压阻尼器的转动过程,给出了中心转轴的转角-弯矩滞回曲线,其形状接近矩形,具有很好的耗能效果,说明了所构造阻尼器的可行性与有效性;研究了凸缘截面高度对转动弯矩峰值的影响;建立了该类扭转铅挤压阻尼器转动弯矩峰值的抛物线型估算公式。依此构思,亦可构造多轴扭转铅挤压阻尼器。
Due to efficient energy consumption,good stability and durability,lead extrusion dampers are widely used in passive vibration control of structures. In traditional lead extrusion dampers,the relative translational displacement between lead and shear block causes the plastic deformation of lead,which can consume much energy.In this paper,a new type of torsional lead extrusion damper is proposed,in which the relative rotational moment between the lead and the central shaft is utilized.It is suitable for the vibration control of structures which use relative angular displacement for energy dissipation(such as the relative rotational angle between the beams and columns).It also can transform conventional energy dissipation mechanisms based on relative translational displacement into patterns using relative angular displacement by gears etc.Nonlinear finite element models for this torsional lead extrusion damper are established in ABAQUS based on the plane strain assumption.The simulation of turning processes of uniaxial and biaxial torsional lead extrusion dampers are discussed in detailed.The rectangular hysteresis curves of rotation-moment are presented,which illustrates the feasibility and effectiveness of torsional lead extrusion dampers in energy dissipation.The influence of flange height on maximum rotational moment is investigated.The parabolic evaluation formula of maximum rotational moment is presented for torsional lead extrusion damper.This study provides useful references for the conceiving of multi-axial torsional lead extrusion dampers.