基于模型修正理论和频响函数模式置信准则的简支梁损伤动力评估方法

提出了一种基于频响函数模式置信准则的改进模型修正方法，用以识别各部位的损伤指数，从而对简支梁的损伤进行定量评估。加工制作了4片模型简支钢梁，用切割截面的方式模拟了损伤，进行了动力测试，并利用所提方法进行了损伤识别。简支钢梁数值模拟和模型试验结果表明：利用相邻测点间频响函数模式置信准则指数构造目标函数时，可有效增加识别变量的个数；第1阶频率和第2阶频率之间的区段内频响函数对损伤灵敏度较高，可用SAC指数计算和简支梁损伤识别；所提损伤评估方法对测试系统误差和噪声不敏感，可实现对多个位置损伤的同步定位和定量识别；在传感器数量有限的情况下，采用分步识别法可以实现对损伤位置的逐步接近和损伤程度的精细化识别。

Dynamic evaluation method for damage of simply-supported beams based on model updating theory and FRF signature assurance criterion

A revised model updating method based on the frequency response function (FRF) signature assurance criterion is proposed, by which the damage indexes of different parts can be identified, and furthermore the damage of the simply-supported beam can be quantitatively evaluated. Four simply-supported model steel beams were fabricated and damage was simulated by cutting the sections. The dynamic responses of the model beams were tested and damage identification was conducted by the proposed method. The numerical simulation and the model test results of simply-supported steel beams with different damage indicate that when the signature assurance criterion (SAC) indexes of frequency response functions between adjacent points are used to construct the objective functions, the number of identification parameters can be greatly increased. The frequency response function is sensitive to the frequency band between the first-order and the second-order dominant frequencies, so it can be used in the calculation of SAC indexes and the damage evaluation of simply-supported beams. The proposed damage evaluation method is insensitive to systematic test errors and noises, by which both single damage and multiple damages of the bridge can be simultaneously localized and identified. When the number of transducers is limited, the step-by-step method can be used to approach the true damage locations and identify the damage extents precisely.