钢筋混凝土梁非线性动力特性试验研究

Test Study on the Nonlinear Dynamic Characteristics of Reinforced Concrete Beams

对钢筋混凝土梁非线性动力特性及其损伤程度之间关系做了试验研究。混凝土梁的非线性动力特性通过对冲击振动位移反应信号的时频分析和共振试验获得。把时频分析和共振试验两种方法结合在一起,通过分析得到合适的时频分析所用窗口宽度,再结合时频分析方法,得到各级加载后混凝土梁的振幅与频率关系曲线。通过分析混凝土梁在各级损伤加载后的振幅与频率关系曲线族,总结了损伤钢筋混凝土梁的非线性动力特性,并分析了用钢筋混凝土梁的非线性动力特性做损伤检测的可行性。

In order to study the relationship between the nonlinear dynamic characteristics of reinforced concrete beam and its impairing degree, we do a time-frequency analysis of the displacement responses from the impact excitation vibration test on a reinforced concrete bearn. First, we get a reasonable window width of time-frequency analysis by combining the results of the time-frequency analysis with the results of the harmonic excitation vibration test; then using time-frequency analysis with moving window, we draw the relationship curve between displacement amplitude and its frequency at each impairing level; after that, by analyzing this group of curves we obtain the nonlinear dynamic characteristics of the impairing reinforced concrete beam; finally, we analyze the possibility of using the nonlinear dynamic characteristics of the damaged reinforced concrete beam to detect its damage levels.