基于不完备频响函数的结构多损伤定性和定量识别

传统的频响函数损伤探测方法对单损伤识别效果明显,却难于精确识别多损伤情况。为了解决结构的多损伤位置识别和损伤程度的判定问题,将不完备的频率响应函数应用于结构的损伤检测研究,并提出了一种两阶段的损伤识别方法。首先,利用不完备的频率响应函数确定相应的损伤指标,并通过不同节点和自由度处损伤指标的改变来分别初步判断损伤的位置;然后,推导分析了损伤程度计算公式,利用该公式可以精确的计算出相应损伤单元的损伤程度。仿真结果表明,通过自由度损伤指标的改变可以较为精确的识别出损伤的位置,优于节点损伤指标判别法,而通过损伤定量公式不仅可以得到损伤程度的量化值,而且可以更精确的判断损伤的位置。

QUALITATIVE AND QUANTITATIVE IDENTIFICATION OF MULTIPLE DAMAGES BASED ON INCOMPLETE FREQUENCY RESPONSE FUNCTIONS

Conventional methods using frequency response functions are effective to detect single damage, but are difficult to identify multiple damage locations and extents. In order to solve this problem, a two-stage method using incomplete frequency response functions is presented. The damage detection strategy is to localize the damage locations by using damage index of different nodes or degree-of-freedoms, which can be obtained from measured incomplete frequency response functions. A damage quantification formula is then deduced from the reduced degree-of-freedom system to calculate damage extents. The simulation results demonstrate the excellent performance of the proposed two-stage method based on degree-of-freedoms damage index to detect multiple damages as compared with other methods.