As one of the most effective non-destructive testing technologies for steel core ropes, electromagnetic detection technology has the advantages of high defect recognition rate and good stability, and has achieved fruitful research results in recent years. However, there are still some problems that need to be solved in non-destructive testing technology of steel wire ropes. Future research needs to focus on the following aspects:
1. The influence of the type and structure of the steel core rope on the test results cannot be ignored.
According to the cross-sectional shape of the strands, steel core rope are divided into round strand steel wire ropes and special-shaped strand steel wire ropes. At present, the research on the defects of steel wire ropes mostly uses round strand steel wire ropes, while there is less research on the defects of special-shaped strand steel wire ropes. Due to differences in twisting methods, rope core materials, and number of braiding layers, even the same type of steel wire rope has large differences in magnetization and defect detection. Therefore, further research is needed on the vibration waveform characteristics and damage identification of different types of wire rope defect signals.
2. Pay attention to the impact of wire rope impact defect shape and spatial distribution on damage identification.
The fracture shape, fracture depth and width of the wire rope impact defect are important factors that affect the accuracy of defect identification. The spatial distribution of impact defects in wire ropes is different, that is, internal/external defects, concentrated defects in the same strand/different strands, etc., which have an important impact on the accuracy of quantitative analysis of defects. Therefore, in-depth research on the shape and spatial distribution of impact defects in wire ropes is of great significance for damage identification and quantitative analysis.
3. Improve the signal-to-noise ratio and calculation speed of the wire rope defect signal.
The non-periodic impact defect signal of the wire rope is mixed with wave noise, vibration noise and background noise, which seriously affects the identification of the defect signal. In particular, the identification and extraction of weak signals from wire ropes under strong noise backgrounds require further research. Studying new methods suitable for identifying and extracting weak signals from steel wire ropes under strong noise background, as well as improving the practicality of existing methods, are the focus of future research. Applying ideas such as population optimization and adaptive optimization to improve the parameter selection of these algorithms can improve the efficiency and accuracy of damage identification.
4. Pay attention to the research on quantitative analysis of wire rope defects and life prediction.
Quantitative analysis of wire rope defects and life prediction are difficult and hot issues in current research. The selection of wire rope structure, defect morphology, signal processing and quantitative analysis methods all have a crucial impact on the accuracy of defect quantification. The evolution of the shape and degree of wire impact defects is usually an important parameter that affects the prediction of wire rope life. Therefore, the quantitative analysis of impact defects and life prediction of steel wire ropes require more in-depth research.
5. Migrate the integrated application of new technologies and new methods.
At present, wire rope electromagnetic detection technology mainly includes three steps: signal preprocessing, feature extraction, qualitative determination of damage, and quantitative analysis. However, the selection and extraction methods of feature values have a great impact on the results of qualitative identification and quantitative analysis, and the steps are cumbersome. Therefore, based on the deep learning method, that is, directly substituting into the deep neural network for training without feature extraction, it will become a research trend in the qualitative judgment and quantitative analysis of wire rope damage. Moreover, a single detection technology cannot solve all wire rope damage problems. It is necessary to study multi-method and multi-index fusion detection technology under multi-detection technology to improve the accuracy of wire rope damage identification and quantitative analysis.
6. Strengthen the transformation and on-site application of theoretical results.
Due to the diversity of wire rope structures, specifications, and mine working conditions, existing non-destructive testing equipment cannot perform universal testing. For the different signal characteristics brought by different wire rope structures, certain algorithms should be studied to weaken the structural characteristics in the signal. For changes in lift-off value caused by different wire rope specifications, a certain algorithm should be studied to compensate or a variable lift-off value adjustment structure should be adopted. Regarding the diversity of on-site working conditions of wire ropes, such as high-speed detection, heavy load detection, offline shutdown detection and online real-time monitoring, in-depth research should be conducted on special working conditions.
