基于应变响应二次协方差的梁结构损伤识别研究

Research on Damage Identification of Beam Structures Based on Quadratic Covariance of Strain Responses

提出在时域内建立基于应变响应二次协方差矩阵来识别结构损伤。推导证明了应变响应二次协方差矩阵(QCoS)元素的解析公式,它是结构频率、振型和阻尼等模态参数的函数。基于结构应变响应二次协方差矩阵元素构造损伤特征向量,结合向量置信度准则和应变响应二次协方差矩阵元素差值,对结构的损伤进行检测和定位。通过数值模拟证明了该损伤识别方法的有效性。

It is proposed to construct the quadratic covariance matrix based on strain responses in the time domain to identify the damage to the structure. An analytical formulation for the elements of the quadratic covariance matrix of strain responses (QCoS) is derived. QCoS is proved as a function of modal parameters such as structural frequency, mode shape and damping. The damage eigenvectors are constructed based on QCoS. Through the vector confidence criterion and the difference of QCoS, the damage to a structure is detected and located. Numerical simulation results prove the effectiveness of the proposed damage identification method.