环形橡胶支座力学性能试验研究与有限元分析

Experimental study and finite element analysis of mechanical behavior of annular rubber bearings

随着环形橡胶支座在文物及大型设备隔震等方面应用需求的增长,对环形橡胶支座的力学性能的准确掌握越来越重要。目前,虽然部分学者已提出环形橡胶支座的水平与竖向刚度的计算公式,但其对不同参数特征的环形橡胶支座的适应性还未经过试验验证,此外,支座水平与竖向刚度的压应力相关性也亟需进一步研究。因此,聚焦环形橡胶支座的水平与竖向力学性能,通过试验对现有计算公式进行评估,并重点研究支座的水平与竖向刚度的压应力相关性;基于试验建立环形橡胶支座的有限元模型,参数化分析不同特征参数的环形橡胶支座在不同压应力及水平剪应变下的水平刚度、竖向刚度及其内部应力分布变化规律,并量化分析不同压应力与剪应变对支座各项力学性能的影响。研究结果表明:环形橡胶支座的水平与竖向刚度均呈现出显著的压应力相关性;第一形状系数与第二形状系数对环形橡胶支座的水平与竖向力学性能均产生影响,第一形状系数对支座的竖向等效刚度与等效应力影响更大,而第二形状系数对支座的水平等效刚度影响更大;在不同加载工况下,环形橡胶支座内钢板层的Mise等效应力均远大于橡胶层。

With the growth of the application demands of the annular rubber bearings in seismic isolation of cultural relics and equipments,it is more and more important to quantitatively grasp the mechanical properties of the annular rubber bearings.At present,although the formula for calculating the horizontal and vertical stiffness of annular rubber bearings has been proposed,the adaptability of the formula to annular rubber bearings with different parameter characteristics has not been verified by tests,and the compressive stress correlation of the horizontal and vertical stiffness of the bearings also needs further study.Therefore,this paper focuses on the horizontal and vertical mechanical properties of annular rubber bearings,evaluates the accuracy of the existing calculation formula through tests,and studies the compressive stress correlation between the horizontal and vertical stiffness of bearings.Finite element models of annular rubber bearings are established based on the experiment,the parameter analysis is conducted to study the horizontal stiffness,vertical stiffness,and its internal stress distribution variation law of the annular rubber bearings with various parameters under different compressive stress and horizontal shear strain.The influence of the compressive stress and the shear strain on the mechanical properties of the bearing is also quantitatively analyzed.The results show that the horizontal and vertical stiffness of the annular rubber bearings shows a significant compressive stress correlation.The first shape coefficient and the second shape coefficient have an effect on the horizontal and vertical mechanical properties of the annular rubber bearing,while the first shape coefficient has a greater effect on the vertical equivalent stiffness and equivalent stress of the bearing,and the second shape coefficient has a greater effect on the horizontal equivalent stiffness of the bearing.Under different loading conditions,the Mise equivalent stress of the steel plate layer in annular rubber bearing is much larger than that of the rubber layer.