铅芯橡胶支座在极低温度下的力学性能研究

Research on mechanical properties of lead rubber bearing at extremely low temperature

在-40℃、-30℃、-20℃、-10℃和23℃下对铅芯橡胶支座(LRB)进行了拟静力试验,系统地探究了低温变化对支座力学性能的影响及其力学参数的变化规律。试验表明:以支座在室温23℃下的力学性能为基准,各低温下的力学性能与之相比差异较大。支座的等效阻尼比、屈服后刚度、屈服剪力、水平等效刚度和竖向刚度均随着温度的降低非线性增长,其中支座的竖向刚度、水平等效刚度和屈服剪力受低温的影响大,等效阻尼比和屈服后刚度受其影响较小。随着温度的降低,滞回曲线的形状逐渐饱满,面积逐渐增大,且有上翘的趋势。本文结论为冬季温度较低的高烈度地区的隔震设计提供了依据。

Pseudo-static tests were conducted on lead rubber bearings(LRB) at-40 ℃,-30 ℃,-20 ℃,-10 ℃ and 23 ℃.The effect of low temperature changes on the mechanical properties and the changing law of mechanical parameters of the bearing were systematically explored. Tests show that the difference between the mechanical properties of the support at room temperature 23 ℃ and the mechanical properties at low temperatures is large. Generally speaking, the equivalent damping ratio, post-yield stiffness, yield shear force, horizontal equivalent stiffness and vertical stiffness of the bearing increase nonlinearly with the decrease of temperature. Among them, the vertical stiffness, horizontal equivalent stiffness and the yield shear force are greatly affected by low temperature, and the equivalent damping ratio and post-yield stiffness are less. As the temperature decreases, the shape of the hysteresis curve is gradually full, the area gradually increases, and there is a tendency to upturn. It provides a basis for isolation design in high-intensity areas with low winter temperature.