基于改进的传递熵理论,利用高斯白噪声激励下混凝土简支梁上多处相邻节点上的加速度响应信号进行损伤识别.分析中,假定梁结构在各损伤工况下均保持线弹性,且只在主平面内弯曲振动.为保证计算结果的可靠性,在每个损伤工况下均进行多次数据采样,利用不同时间尺度上的传递熵均值进行损伤识别.对传递熵曲面的分析结果表明:不同进程间的传递熵在某些特定的时间延滞上会出现局部最小值,并且该时间延滞将会随着损伤的发生而产生变化.通过对比改进的传递熵与未改进的传递熵,发现前者在损伤识别方面更加敏感,并且当结构的损伤较微弱时,改进的传递熵可能具备损伤定量和定位的能力.改进的传递熵具有相当强的鲁棒性,适合实际应用.
A modified transfer entropy method was proposed to identify the change in a simply supported concrete beam structure by using acceleration signals from different adjacent nodes when the beam was subjected to Gaussian excitation.The beam was assumed to maintain linear elasticity and the vibration only exists in its principal plane throughout the analysis.To ensure the reliability of the results,the acceleration data were sampled several times and the mean of transfer entropy at different time scales was applied to detect the damage.The analysis of transfer entropy surfaces showed that transfer entropy would reach local minima at several special time delays and these time delays would alter while the damage took place.By comparing the modified transfer entropy to unmodified one,the former was found to be more sensitive in damage detection.Besides,the modified transfer entropy may be capable of quantifying and locating the damage in structures while the damage is relatively weak,and this method is suitable for practical application due to its strong robustness.