带缝钢板阻尼器受力性能试验研究

Experimental study on mechanical properties of steel dampers with slits

对4组弯曲单元宽厚比小于5的带缝钢板阻尼器进行了低周往复拟静力试验，研究其力学特性和耗能能力，利用试验结果检验了现有阻尼器的刚度和强度设计公式。建立有限元模型模拟阻尼器破坏的全过程，通过参数分析研究了带缝钢板阻尼器的延性系数、损伤发展机制、超强系数及累积耗能和累积塑性变形。研究表明：带缝钢板阻尼器具有稳定的平面内力学性能、低周疲劳性能和较强的耗能能力，等效黏滞阻尼系数约为0．5；阻尼器延性较好，当弯曲单元高宽比“不小于4时，延性系数受其影响较小，因此不应采用α小于4的阻尼器；带缝钢板阻尼器的超强系数在2．30～2．96之间；累积塑性变形角与d成正比、标准累积塑性耗能率与α成反比，提出的公式可用于指导消能减霹结构设计和阳屁器诜利．

This paper studies the mechanical properties and energy dissipation capacity of steel dampers with slits through low-cycle quasi-static test on four groups of specimens with width-to-thickness ratio less than 5. Available stiffness and strength design equations are examined and calibrated by the experimental results. Then sophisticated finite element models are used to simulate the complete performance of dampers from yield through fracture failure, based on which important performance factors, such as the ductility factor, damage progress, over-strength ratio, and accumulated plastification, are carefully investigated. It is demonstrated that the proposed damper is featured with stable mechanical properties, and good energy-dissipation capacity with the equivalent damping ratio close to 0.5. The ductility factor is larger than 15 and the influence of aspect ratio a is limited if a is larger than 4. The damper with α less than 3 is not recommended because of its lower ductility. The over-strength ratio is between 2.30 and 2.96, which shall be carefully considered during design. It is also observed that the accumulated plastic deformation is proportional to α , while the standardized accumulative energy dissipation ratio is inversely proportional to α.