Generally, the damage of the structure will lead to the discontinuity of the local mode shape, which can be well reflected by the modal curvature of the structure, and the local information entropy of the beam structure will also change with the discontinuity of the mode. In this paper, based on the information entropy theory and combining the advantages of modal curvature index in damage identification of beam structure, the modal curvature utility information entropy index is proposed. The modal curvature curves of nondestructive structures were obtained by fitting the modal curvature curves of damage structures with the gapped smoothing technique to avoid dependence on the baseline data of nondestructive structures. The index comprehensively reflects the damage state of the structure by calculating mutual weight change matrix and the weight-probability coefficient. The performance of the new index was verified by the finite element simulation and model test of simply supported beam, respectively. The results show that the modal curvature utility information entropy index takes advantage of the modal curvature index which is sensitive to damage and can overcome its shortcomings effectively. The index proposed can identify the damage location and damage degree accurately and has certain noise immunity, which provides an effective damage identification indicator for beam structures.

中文翻译：

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基于模态曲率效用信息熵的梁结构损伤识别方法

通常，结构的损坏会导致局部模态形状的不连续性，这可以很好地反映在结构的模态曲率中，梁结构的局部信息熵也会随着模态的不连续性而变化。本文基于信息熵理论，结合模态曲率指标在梁结构损伤识别中的优势，提出了模态曲率效用信息熵指标。通过使用间隙平滑技术对损伤结构的模态曲率曲线进行拟合，以避免依赖于非破坏性结构的基线数据，可以获取非破坏性结构的模态曲率曲线。该指标通过计算相互的权重变化矩阵和权重概率系数，全面反映结构的损伤状态。分别通过有限元模拟和简单支撑梁的模型测试来验证新指标的性能。结果表明，模态曲率效用信息熵指标利用了对损伤敏感的模态曲率指标，可以有效克服其缺点。提出的指标可以准确识别损伤部位和损伤程度，并具有一定的抗噪能力，为梁结构提供了有效的损伤识别指标。结果表明，模态曲率效用信息熵指标利用了对损伤敏感的模态曲率指标，可以有效克服其缺点。提出的指标可以准确识别损伤部位和损伤程度，并具有一定的抗噪能力，为梁结构提供了有效的损伤识别指标。结果表明，模态曲率效用信息熵指标利用了对损伤敏感的模态曲率指标，可以有效克服其缺点。提出的指标可以准确识别损伤部位和损伤程度，并具有一定的抗噪能力，为梁结构提供了有效的损伤识别指标。