摘要
研究了平台下部结构的不同位置发生不同程度损伤时 ,利用数值计算可以得到平台结构的固有频率、振型、模态应变能、频响函数等有关参数。利用上述参数变化 ,可以用来识别损伤、损伤位置以及损伤程度。研究表明 ,振型参数可以用来对损伤进行定位 ,模态应变能方法可以发现结构的早期损伤 ,而频响函数可以发现下部结构任何构件的断裂 ;借助于小波变换对频响函数进行分析 ,可以发现早期结构损伤。
Crack detection criteria based on diff erent parameters, such as frequency, modal shape, modal strain energy (MSE) and frequency response function (FRF), are illustrated. When cracks at different loc ations and of different magnitudes exist in the underwater structure, these para meters of the jacket can be obtained numerically. The shift of the parameters ca n be used to identify the crack, its location and its magnitude. Frequency can b e easily measured to detect the existence of a crack in the global detection, bu t the crack location cannot be predicted. Modal parameters can be used to locali ze the crack in the local detection. MSE criteria can predict the very early cra ck. And FRF can be used to predict any breakage of beams in the lower structure. Wavelet transform can be used to predict early cracks.
出处
《上海造船》
2005年第1期27-30,共4页
Shanghai Shipbuilding
