扭转作用下高阻尼橡胶支座力学性能试验研究

Tests for mechanical performance of high damping rubber bearing under torsion

在隔震建筑向高烈度区、大体量、高层、复杂体型发展的趋势下,隔震支座会出现拉力、压力、弯矩、剪力、扭矩同时发生的复杂受力情况,困扰工程安全及技术推广。针对以上问题,设计了一套扭转加载试验方案,主要对典型尺寸的原型高阻尼橡胶支座(HDRB600)进行了扭转作用下的静力试验研究,得到了试件的力学性能;同时,采用三维散斑测量分析系统对试件的表面应变进行非接触测量。结果表明:竖向力对支座水平剪切性能、扭转性能影响较为明显;绕Z轴扭转滞回曲线呈方形,饱满有规律,加载至扭转角度8.4°未见明显的承载力下降和破坏现象;绕X轴扭转滞回曲线呈平行四边形,较为饱满,规律性强;绕X轴和绕Z轴扭转均会影响支座的水平性能,导致支座水平性能降低。三维散斑测量结果表明:表面橡胶应变云图分布不均匀,呈现出中部大,上下端部小的特点,间接判断其内部橡胶层的受力情况与传统理论有所不同。

With the development trend of isolated buildings to high intensity area,large volume,high-rise and complex shape,isolation bearing can have the complicated load-bearing problem of tensile force,pressure,bending moment,shear force and torque simultaneously occurring,it puzzles the engineering safety and technology promotion.Here,aiming at this problem,a set of torsion loading test schemes was designed,static tests were conducted on the original high damping rubber bearing(HDRB600)with typical size under torsion to obtain the specimen’s mechanical performance.At the same time,non-contact measurement of the specimen’s surface strain was performed using the 3 D speckle measurement and analysis system.The results showed that effects of vertical force on horizontal shear performance and torsional performance of the bearing are more obvious;the torsional hysteretic curve about z-axis is square,full and regular,and there is no obvious load-bearing capacity decline and failure phenomenon when loading to the torsion angle of 8.4°;the torsional hysteretic curve about x-axis is parallelogram,fuller and regular;torsions about x-axis and z-axis can affect horizontal performance of the bearing to reduce its horizontal performance.The results of 3 D speckle measurement showed that the distribution of the surface rubber strain cloud-graph is uneven,it has features of large in middle and small in upper and lower ends,so there is an indirect judgment of the inner rubber layer stress distribution being different from what the traditional theory describing.