结构和构件损伤判别及阻尼比变化规律研究

Research on damage identification and damping ratio variation law of structures and components

基于动力特性的建筑结构健康监测具有操作便捷及高效反馈的特点,是建筑结构健康监测最常用的手段之一。动力特性中的自振频率等内容已被广泛研究和应用,而阻尼比这一重要参数的关注却比较少。研究认为国内外规范设计中将阻尼比值规定为常数的方法,忽略了阻尼比值在弹塑性阶段的变化规律。总结了黏滞阻尼模型、库伦阻尼模型和复阻尼模型这3种常见的阻尼比模型,并着重分析了应用最广泛的黏滞阻尼模型,介绍了损伤状态的判别方法。在此基础上,整理总结了在不同损伤状态下结构和构件阻尼比变化的公式和趋势的探索研究。最后,将黏滞阻尼模型和不同损伤状态下阻尼比变化规律进行了总结,建议将阻尼比和自振频率综合在一起作为损伤指标以更全面评估损伤状态。

Dynamic properties-based structural monitoring is one of the most commonly used health monitoring approaches due to the convenience of operation and data reading.Although the natural frequency of dynamic characteristics has been widely studied and applied,it has been paid less attention to the significant parameter-damping ratio.Research shows that specifying the damping ratio value as a constant in domestic and international design codes ignores the variation law of the damping ratio in the elastic-plastic phase.This paper summarizes the definition and details of three common damping ratio models,including the damping model,Coulomb damping model,and complex damping model respectively.More attention has been focused on the most widely used viscous damping model,and methods for distinguished the damage state are introduced.On this basis,an exploratory study of the equations and trends on the damping ratio changes of structures and components in different damage states is collated and summarized.Eventually,a summary and outlook of the viscous damping model and damping ratio under different damage states are presented,and it is suggested that the damping ratio and the natural frequency could be combined as damage indicators for a more comprehensive assessment of damage states of structures and components.