铅芯橡胶支座多向受力力学性能试验研究

摘要

研究目的:目前,对铅芯橡胶支座力学性能的研究主要是基于支座的水平单向压剪试验,然而,在实际地震中橡胶支座处于多向受力状态下,因而有必要对支座在多向受力状态下的力学性能进行研究.本文采用低周反复循环加载试验方法对铅芯橡胶支座进行水平单向压剪试验和水平双向压剪试验,研究多向受力对支座力学性能的影响,并对水平双向压剪作用下支座的剪切性能进行模拟.研究结论:(1)与水平单向压剪作用下相比,铅芯橡胶支座在水平双向压剪作用下的耗能能力、屈服力、屈服后刚度、水平等效刚度和等效阻尼比均有一定程度的减小;(2)根据铅芯橡胶支座在水平单向压剪作用下剪切性能的经验公式,可以较为有效地模拟支座在水平双向压剪作用下的剪切性能,但在压应力较大时计算值和试验值有较大误差,使用时应予以关注;(3)该研究成果对隔震结构的设计和分析具有参考价值.%Research purposes:At present,the research on the mechanical properties of lead rubber bearing is mainly based on the uni-directional compressive-shear test of the bearings.However,in the actual earthquake,the rubber bearing is in the multi-directional loading state.So it is necessary to study the mechanical properties of the bearings under multi-directional loading.In this paper,the low-cycle cyclic loading test method is used to study the mechanical properties of the lead rubber bearings,the uni-directional and bi-directional compressive-shear tests of the bearings were carried out.The influence of multi-directional loading on the mechanical properties of the bearings was studied,and the shear properties of the bearings under bi-directional compressive-shear state were simulated.Research conclusions:(1) Comparing with the results of the uni-directional compressive-shear tests,the energy dissipation,yield force,post yield stiffness,horizontal equivalent stiffness,and equivalent damping ratio of the lead rubber bearings under bi-directional compressive-shear tests decrease.(2) According to the shear properties empirical formula of the lead rubber bearings under uni-directional compressive-shear tests,the shear properties of the bearings under bi-directional compressive-shear tests can be effectively simulated,but when the compressive stress is larger,the error between the calculated values and experimental values is much bigger,so it should be concerned about this case.(3) The research results are helpful to the design and analysis of the isolated structures.