Structural Damage Detection Based on Measurement Point Layout and Model Updating Method

基於量測點佈局與模型更新方法的結構損傷檢測

李念龍(Nien-Lung Lee)

《中國機械工程學刊》 41卷4期 (2020/08) Pp. 449-456

摘要

In this study, a method is proposed for detecting the structural damage position and extent by combining the measurement point layout and model updating method. Initially, the finite element analysis (FEA) model of the structure is applied to evaluate the appropriate measurement point layout for the modal test. The method proposed in this study is based on the functional complementarity of the integrated modal kinetic energy (MKE) and Hemez methods. The method includes the MKE cumulative value for the number of measurement points and the Hemez method for reasonable positions. Model variables, such as the cross-sectional area and quadratic moment of inertia, are used to represent the geometrical or material properties of the structure. Further, the model updating method takes advantage of the eigensensitivity matrix, and the model variables of the FEA model are updated by iterative calculation. The results demonstrate that the analysis results of the updated model variables of the FEA model can approach the pre-simulated damage positions and extent of the reference model. The measurement and model updating methods developed in this study can be applied for the monitoring and early warning of structural damage.

關鍵字

Iterative methods ； sensitivity-based iterative model updating method ； finite element model ； damage detection

並列摘要

本研究提出了一種結合量測點佈局與模型更新方法作為檢測結構損傷位置與程度的方法。最初，結構的有限元分析（FEA）模型用於評估模態測試的適當量測點佈局。本研究中提出的方法是基於結合模態動能（MKE）與Hemez方法的功能互補性。該方法利用MKE累積值求取量測點數量，及Hemez方法求取合理量測位置。模型變量（例如：橫截面積和二次慣性矩）用於表示結構的幾何或材料特性。此外，模型更新方法利用特徵靈敏度矩陣，並且透過迭代計算以更新FEA模型的模型變量。結果顯示更新FEA模型後，模型變量的分析結果可以逼近參考模型預先模擬的結構損傷位置與程度。這項研究發展的量測與模型更新方法可應用於結構損傷的監測和預警。