超弹性本构模型在隔震支座设计中的适用性研究
2017-02-05彭泽友李文华王永祥刘乐
彭泽友 李文华 王永祥 刘乐
摘要:通过对MooneyRivlin本构和Ogden本构进行研究,得出2种典型超弹性本构模型在辅助隔震橡胶支座设计分析中的适用性,并对2种本构模型进行隔震橡胶支座竖向刚度和水平刚度模拟。结果表明:工程应变小于1.33时可选择MooneyRivlin本构模型;工程应变在1.33与4之间可选择Ogden本构模型;MooneyRivlin本构模拟隔震橡胶支座的竖向压缩与Ogden本构模拟隔震橡胶支座水平剪切刚度均与试验结果吻合较好。
关键词:超弹性本构模型;隔震橡胶支座;非线性有限元;应变能密度函数
中图分类号:U443.36文献标志码:B
Abstract: Two typical superelastic constitutive models, MooneyRivlin and Ogden, were studied in regard to their applicability to the design of rubber isolation bearings. Simulation of vertical and horizontal stiffness was conducted on the aforementioned models. The results show that the MooneyRivlin model is applicable when the engineering strain is less than 1.33, while the Ogden model shall be chosen when the engineering strain ranges from 1.33 to 4; both the simulation of vertical compression of rubber isolation bearing with the MooneyRivlin model and simulation of horizontal shear stiffness with the Ogden model are consistent with test results.
Key words: superelastic constitutive model; rubber isolation bearing; nonlinear finite element; strain energy density function
0引言
桥梁作为生命线工程,在地震时保持良好的抗震性能意义重大[1]。传统桥梁抗震是采用加大截面及配筋来增强结构构件的抗震能力,而隔震是通过在梁体与墩、台连接处设置水平柔性支撑和能量耗散装置来延长桥梁结构的周期,并增加结构的阻尼,以减小地震反应,其效果不仅在试验研究和理论分析中得到很好的证明[23],并且经过实际地震的检验[45]。高阻尼橡胶支座是采用高阻尼橡胶材料与钢板等结构件硫化而成的一种橡胶支座,既可以保持普通橡胶支座所具有的良好力学特性,同时具有较高的阻尼,在地震中可以有效地吸收地震能量,减轻地震响应,达到隔震效果。目前,对高阻尼橡胶支座的整体研究较多,但对高阻尼橡胶材料超弹性本构的研究较少。针对这种情况,本文根据橡胶的基本试验曲线,拟合出2种典型的橡胶本构方程……
