超低硬度橡胶隔震支座水平力学性能相关性试验研究

Experimental study on dependence of horizontal mechanical property of elastomeric isolators with ultra-low hardness

本文目的是研究G值约为0.196MPa的超低硬度天然橡胶隔震支座(LNR)和铅芯橡胶隔震支座(LRB)的水平基本力学性能的各种相关性能变化规律。采用反复加载的试验方法研究了LNR及LRB支座剪切性能的水平剪应变相关性、压应力相关性和水平加载频率相关性、温度相关性、反复加载次数相关性、老化相关性、水平极限应变相关性。通过试验研究,分析了各种相关性因素对支座水平性能的影响,给出了主要相关性变化规律的拟合近似公式,并和有关文献的结果进行了比较。从各种相关性对支座水平性能影响程度来看,水平剪应变、竖向压应力、温度、频率对其有一定程度影响,而老化、反复加载次数、大变形对其影响有限。试验结果还表明,部分文献夸大了应变在低应变阶段对LNR水平刚度的影响,低估了其对LRB屈服后刚度和屈服强度在小应变和大应变阶段的影响。

The intention of this paper is to research the dependence of the horizontal fundamental mechanical property of LRB and LNR with shear modulus about 0. 196 MPa. The cyclic loading method was adopted and a series of tests were performed,which included shear strain dependence,compression dependence,loading frequency dependence,temperature dependence,repeated loading dependence,aging dependence and ultimate shear strain dependence. All kinds of dependence effects on the horizontal property of LNR or LRB were analyzed,some fitting formulas about those change rules were given after tests,and compared to the results of some literatures. Test results show that shear stain,vertical pressure,temperature,loading frequency have some influence on the horizontal mechanical property of LNR or LRB,but there is little effects on them for aging,repeated loading,ultimate shear strain. It also shows that shear strain effect on the horizontal stiffness of LNR at the stage of low strain has been overstated,but its effect on the post-yield stiffness and yield strength of LRB at the stage of small strain and large strain have been underestimated.