【作者】 杨和振； 李华军； 黄维平；

【Author】 Yang Hezhen Li Huajun Huang Weiping (Engineering College, Ocean University of China, Qingdao, 266071)

【机构】 中国海洋大学工程学院；

【摘要】 本文针对海洋平台等复杂大型土木工程结构物,研究基于动力响应测试的无损检测方法,提出一套利用结构单元模态应变能特性的新损伤诊断方法。该方法是将结构单元的模态应变能分解为拉压模态应变能和弯曲模态应变能,并定义了两个损伤诊断指标,即拉压模态应变能变化率(CMSECR)和弯曲模态应变能变化率(FMSECR)。模态应变能是通过结构不完备振型和结构刚度矩阵计算出的,因此,可以通过动力响应测试得到结构单元的两个损伤指标诊断结构的损伤。为了验证本文所提出损伤诊断方法的正确性,利用海洋平台有限元模型数值模拟了几个具有代表意义的损伤工况。根据损伤诊断结果,本文所提方法能够得到满意的诊断精度,具有一定的实际应用价值。更多还原

【Abstract】 In this paper Nondestructive Damage Detection (NDD) in large/complex structures is investigated via vibration monitoring of offshore platform . A new method of damage detection is presented,which utilizes an invariance property of element modal strain energy .The theory of NDD for frame type structure is formulated. This method was based on assigning element modal strain energy to two parts ,and defined two damage detection indexes . One is compression modal strain energy change ratio (CMSECR).the other is flexural modal strain energy change ratio (FMSECR). The present modal strain energy are obtained by incomplete modal shape and structural stiffness matrix .Structure health monitoring is thus accomplished via monitoring the elemental CMSECR and FMSECR .Several damage cases are simulated by offshore platform numerical model (FEM) ,and presented to illustrate the utility of the proposed method. According to the results, the proposed method is shown to be effective for the complex structural damage detection and has satisfactory precision.更多还原