高竖向承载力MRE支座的试验和力学模型研究

Experimental study and mechanical model of high vertical bearing capacity MRE bearings

磁流变弹性体(magneto-rheological elastomer,MRE)隔震支座竖向承载力低,竖向荷载对支座力学性能影响显著,限制了MRE支座的工程应用。通过增设竖向连杆承担竖向荷载,永磁铁提供恒定磁场,研发了MRE片与钢板交替叠合、剪切刚度双向可调的隔震支座。采用有限元方法分析了MRE片厚度、永磁铁厚度和永磁铁放置位置等对支座磁路的影响,设计制作了芯体直径为60 mm,由26片MRE和25片钢板组成的MRE叠层隔震支座。开展了不同频率、振幅、电流大小和配重下支座力学性能试验,基于试验结果,采用粒子群算法对支座的Bouc-Wen模型进行参数识别,建立了支座的Bouc-Wen模型。结果表明,所设计的MRE支座竖向承载力高,力学性能稳定,Bouc-Wen模型可以准确地描述支座的滞回特性,拟合数据与试验结果吻合较好。

The vertical load-bearing capacity of magneto-rheological elastomer(MRE)isolation bearings is low.However,vertical load has significant influences on the mechanical performance of the MRE bearings,which limits the engineering applications of MRE bearings.By adding vertical rods to bear vertical loads and a constant magnetic field with permanent magnets,an isolation bearing witha structure of MRE sheets and steel plates alternately stacked and bi-directional adjustable shear stiffness was designed and built.The finite element method was used to analyze the effects of MRE layer thickness,permanent magnet thickness,and magnet placement on the bearing’s magnetic circuit.The bearing has a core diameter of 60 mm,consisting of 26 layers of MRE and 25 layers of steel plates.Mechanical performance tests of the bearing were conducted under sinusoidal waves of different frequencies and amplitudes under different currents and weights.Based on the test results,the particle swarm optimization algorithm was used to identify the parameters of the Bouc-Wen model of the bearing.Results show that the MRE bearing has a high vertical load bearing capacity and stable mechanical performance.The Bouc-Wen model can accurately describe the hysteresis characteristics of the bearing,and the fitting data is in good agreement with the experimental results.