In this paper, we propose a pre-processing method for the detection of wire-rope signals. This is necessary because of the lack of processing methods that are currently employed. First, we investigated the one-dimensi...In this paper, we propose a pre-processing method for the detection of wire-rope signals. This is necessary because of the lack of processing methods that are currently employed. First, we investigated the one-dimensional discrete morphological and wavelet transform. Then, we developed a pre-processing model that is based on the morphological wavelet-filtering algorithm. We then proposed a modified morphology filtering algorithm. We also designed an experiment platform for wire-rope detection.Eight levels of localized flaws(LFs) and damage were formed in the wire-rope specimen. We performed a series of experimental studies, and the results show that the proposed method can effectively filter the drift signal. The signal-to-noise ratio of the new filtering algorithm was over 26 d B. The signal-to-noise ratio of the existing method is less than 15 d B, and the noise-signal ratio of the new filtering algorithm has improved by 73%. Based on our results, the filtering effect of the proposed method is better than that of the present method. This study has great significance and practical value in engineering applications.展开更多
Various proportional and nonproportional tension-torsion fatigue tests are conducted on aeronautical material-LY12CZ aluminum alloy. The stress and strain states under tension-torsion loading are analyzed by an elasti...Various proportional and nonproportional tension-torsion fatigue tests are conducted on aeronautical material-LY12CZ aluminum alloy. The stress and strain states under tension-torsion loading are analyzed by an elastic-plastic finite element method. The relation between the orientation of crack propagation and each stress and strain component is investigated. Analytical results are compared with experimental data. Results demonstrate that the fatigue cracks tend to be propagated perpendicular to the direction of the largest principle strains under proportional loading, and grow alone one of the maximum shear strain planes under 45° and 90° out-of-phase loadings.展开更多
基金the National Natural Science Foundation of China (No. 51404276)the Fundamental Research Funds for the Central Universities (Nos. 2014QJ01 and 2015QJ04)
文摘In this paper, we propose a pre-processing method for the detection of wire-rope signals. This is necessary because of the lack of processing methods that are currently employed. First, we investigated the one-dimensional discrete morphological and wavelet transform. Then, we developed a pre-processing model that is based on the morphological wavelet-filtering algorithm. We then proposed a modified morphology filtering algorithm. We also designed an experiment platform for wire-rope detection.Eight levels of localized flaws(LFs) and damage were formed in the wire-rope specimen. We performed a series of experimental studies, and the results show that the proposed method can effectively filter the drift signal. The signal-to-noise ratio of the new filtering algorithm was over 26 d B. The signal-to-noise ratio of the existing method is less than 15 d B, and the noise-signal ratio of the new filtering algorithm has improved by 73%. Based on our results, the filtering effect of the proposed method is better than that of the present method. This study has great significance and practical value in engineering applications.
文摘Various proportional and nonproportional tension-torsion fatigue tests are conducted on aeronautical material-LY12CZ aluminum alloy. The stress and strain states under tension-torsion loading are analyzed by an elastic-plastic finite element method. The relation between the orientation of crack propagation and each stress and strain component is investigated. Analytical results are compared with experimental data. Results demonstrate that the fatigue cracks tend to be propagated perpendicular to the direction of the largest principle strains under proportional loading, and grow alone one of the maximum shear strain planes under 45° and 90° out-of-phase loadings.