基于低阶特征值的结构分散化损伤识别与整体状态评估

Structural discretized damage detection and integral status assessment based on the lower eigenvalue

针对大型复杂结构状态评估问题,提出了基于低阶特征值的结构分散化损伤识别与整体状态评估方法。首先通过有限元法把实际结构离散成用基本参数表示的分析模型,然后采用主从自由度法把它划分为识别部分和非识别部分,对识别部分定义误差函数并建立状态评估目标函数,推导局部损伤识别的计算公式;在此基础上提出分散化损伤识别的概念,形成服役结构整体状态评估方法。最后通过数值模拟,对识别算法性能进行了详细的分析研究,通过整体平均识别误差指标显示了所提方法的有效性和准确性。

A discretized damage detection and integral status assessment scheme based on the lower eigenvalues is proposed to evaluate the status of a large scale structure.Firstly,a real structure,which was divided into identified part and non-identified part according to principal and subordinate freedom degrees,was parameterized as analytical model by finite-element method.Then error estimator between the real structure and its analytical model was defined,and deduced an algorithm of damage detection.Finally it put out the concept of discretized damage detection and proposes the complete method.To study the error extents of the identified results affected by the number of measured frequency ranks a numerical example was presented in details,which illustrated the effectiveness and usefulness of the proposed procedure.