Multiple Cracks Identification of Free-Free Beam with Uniform Material Property Variation and Noised Frequency Measurement
|關鍵字:||破壞診斷;多裂縫;樑;變異;蒙地卡羅;damage assessment;multiple cracks;beam;variation;Monte Carlo|
It is common to apply damage-sensitive features from vibration response for structural damage assessment. Fewer damage identification algorithms have been taken into account the material variation. The material variation could be caused by many reasons in engineering practice, also there may exists certain level noise in measurement, these variations may affect the features used for structure monitoring and lead to an inaccurate damage assessment. In this research the authors proposed a model to assess statistical structural damage of free-free beam structure. The modal curvature-base feature was used to identify crack location. The statistical database for damage severity assessment was build by applying the Monte Carlo simulation with Latin hypercube sampling. By mapping vibration-sensitive features with noised modal frequency to statistical damage database, the damage probability among various crack depths were then estimated; its statistical significance of damage level were examined by the t-test. Data from simulated beams and experimental modal analysis were used to demonstrate the assessment procedures. From the results, the authors concluded that the proposed algorithm was robust and able to identify the damage of free-free beam under uniform mass density and stiffness variations incorporated with noise in measured frequency.
|Appears in Collections:||Thesis|
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