Open Access

ARTICLE

Inverse Load Identification in Stiffened Plate Structure Based on in situ Strain Measurement

by Yihua Wang¹, Zhenhuan Zhou¹, Hao Xu^1,*, Shuai Li², Zhanjun Wu¹

1 Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian, 116024, China
2 Nantong Ocean and Coastal Engineering Research Institute, Hohai University, Nantong, 226000, China

* Corresponding Author: Hao Xu. Email:

Structural Durability & Health Monitoring 2021, 15(2), 85-101. https://doi.org/10.32604/sdhm.2021.014256

Received 14 September 2020; Accepted 25 December 2020; Issue published 03 June 2021

Abstract

For practical engineering structures, it is usually difficult to measure external load distribution in a direct manner, which makes inverse load identification important. Specifically, load identification is a typical inverse problem, for which the models (e.g., response matrix) are often ill-posed, resulting in degraded accuracy and impaired noise immunity of load identification. This study aims at identifying external loads in a stiffened plate structure, through comparing the effectiveness of different methods for parameter selection in regulation problems, including the Generalized Cross Validation (GCV) method, the Ordinary Cross Validation method and the truncated singular value decomposition method. With demonstrated high accuracy, the GCV method is used to identify concentrated loads in three different directions (e.g., vertical, lateral and longitudinal) exerted on a stiffened plate. The results show that the GCV method is able to effectively identify multi-source static loads, with relative errors less than 5%. Moreover, under the situation of swept frequency excitation, when the excitation frequency is near the natural frequency of the structure, the GCV method can achieve much higher accuracy compared with direct inversion. At other excitation frequencies, the average recognition error of the GCV method load identification less than 10%.

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