Papers by Keyword: Structural Damage Identification

Abstract: Based on wavelet transform of strain mode, the damage identification of plane frame was studied in this paper. After solving strain modal parameters of plane frames with cracks by means of the finite element theory, applying the gauss2 wavelet transform to analyze the stain mode of plane frame, and denoising the wavelet coefficients of the strain mode by db3 wavelet, the crack location of the plane frame could be identified by the maximum of wavelet coefficients after denoising. Taking one-story plane frame for example, three finite element models, including a frame beam with a crack, each frame column with a crack, and each frame beam and column with a crack, were set up separately, then the above-mentioned method was applied to identify the location of the crack. The results show the method is effective, and it may be useful in damage identification and diagnosis in structures.

Abstract: As a derivative parameter of the structural displacement mode, damage factor matrix was adopted to investigate the detection of structural crack location and damage. A methodological strategy by combination of the damage factor matrix and the wavelet multi-resolution analysis is presented in the paper, in order to identify structural damages of the cantilevered beam. The results show that damage can be identified by the damage factor matrix and the wavelet multi-resolution analysis, and the damage degree can be estimated by damage frequency band energy of the wavelet analysis. A reference to damage identification in current structure engineering is provided.

Abstract: This paper presents a comprehensive review of computational Intelligence (CI) technology applied in structural damage identification, clarifies the basic principles of computational intelligence techniques, as well as the applicable difficulties that exist in the field of structural damage identification (SDI) from 6 aspects: fuzzy theory, evidence theory, rough set theory, artificial neural networks, support vector machines and evolutionary computation, and then discussed the applicable prospects of computational Intelligence in SDI. It points out that the reasonable cross-fusion of a variety of CI method to specific research object is a necessary means for SDI research. For economy and practicality considerations, CI is suitable for highly integrated complex structural damage identification.

Abstract: With the development of science and technology and the improvement of people's living standard, Natural gas has been widely applied to daily life. But the sharp increase in natural gas explosion accident. In this paper, Analysis of the effects of gas explosion on the structure, and the safety of the structure was evaluated. By detecting the damage phenomena of gas explosion in a civil building, use the characteristics and law of the gas explosion and finite element simulation analysis method.

Abstract: A two-step damage identification method based on elemental modal strain energies and natural frequencies has been presented for a beam-like structure. In the first stage, this method makes use of the change of elemental modal strain energy before and after damage to locate the potential damage regions. And in the second stage, a damage identification algorithm based on the frequency changes is developed to calculate the damage extent and further determine the actual damage locations. The performance of the proposed method is numerically demonstrated by a simply supported beam with two damage cases. Results indicate that the method can identify the damage location and quantify the damage severity accurately in a beam-like structure.

Abstract: The failure of civil engineering structure will lead to heavy losses. So, identifying structural damage is necessary as early as possible. The excellent localization performance of lifting wavelet transform will facilitate significantly damage diagnosis. On the base of wavelet energy distribution of structural acceleration response, taking advantage of characteristics of lifting wavelet and entropy, the structural damage identification method based on lifting wavelet entropy is proposed in this paper. And the lifting wavelet time entropy index and the relative lifting wavelet entropy index are established. The new method and damage indexes are verified in numerical simulation and laboratory test of simple beam. The analysis results show that lifting wavelet time entropy can identify structural damage moment and the relative lifting wavelet entropy can identify structural damage location. The feasibility of method proposed is instructed.

Abstract: In order to improve the accuracy of damage identification of offshore platform, structural damage identification method based on D-S evidence theory is proposed. Firstly, the stiffness matrix damage factor iterative method and modal strain energy method are used to identify the structural damage, and give the decision vectors respectively. Then, the decision vectors are imported into the D-S evidence theory formula, the damage probability of every element would be obtained and the damage location would be determined finally. Offshore platform model experiments show that the results of structural damage identification are more accurate and reliable after D-S evidence theory is used.

Abstract: This paper investigates the sound power radiated from a cracked plate. The sound power is obtained by using a lumped parameters model-based acoustics theory and vibration responses obtained by using the finite element method. It is shown that the vibration mode shapes and crack angle are closely related to the sound radiation characteristics, which can be applied to detect damages such as the cracks generated within a structure.